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In construction and demolition waste (CDW) recycling, the preference to date has been to apply simple but proven techniques to sort and process large quantities of construction rubble in a short time. This contrasts with the increasingly complex composite materials and structures in the mineral building materials industry. An automated, sensor-based sorting of these building materials could complement or replace the practice of manual sorting to improve processing speed, recycling rates, sorting quality, and prevailing health conditions for the executing staff.
A joint project of partners from industry and research institutions approaches this task by investigating and testing the combination of laser-induced breakdown spectroscopy (LIBS) with near-infrared (NIR) spectroscopy and visual imaging. Joint processing of information (data fusion) is expected to significantly improve the sorting quality of CDW, and may enable the detection and separation of impurities such as SO3-cotaining building materials (gypsum, aerated concrete, etc.)
We present current advances and results about the methodological development combining LIBS with NIR spectroscopy and visual imaging. Here, applying data fusion proves itself beneficial to improve recognition rates. In the future, a laboratory prototype will serve as a fully automated measurement setup to allow real-time classification of CDW on a conveyor belt.
Aschen und Schlacken aus der thermischen Abfallbehandlung enthalten eine Vielzahl von Schwermetallverbindungen. Für Antimon, Chrom, Kupfer, Molybdän und Vanadium werden in der neuen Ersatzbaustoffverordnung (Bundesregierung, 2021) Eluatgrenzwerte für die Verwertung festgelegt. Aschen und Schlacken werden aus der Abfallverbrennungsanlage nass ausgetragen und vor einer Verwertung in der Regel mehrere Wochen gelagert. Dabei finden hydraulische Reaktionen statt und enthaltenes CaO wird zu einem Großteil in Calciumcarbonat umgewandelt. Während wässrige Eluate von frischen Aschen pH-Werte von 12 und höher aufweisen, sind die Eluate nach einigen Wochen weniger stark alkalisch. Die gemessenen Schwermetallkonzentrationen sind daher dann auch deutlich niedriger, mit Ausnahme von Antimon (Sb) und Vanadium (V). Hier steigen die Konzentration mit der Lagerungsdauer. Grund sind sinkende Konzentrationen von Ca-Ionen, die sonst zu einer Ausfällung von Antimonaten und Vanadaten führen. Zu hohe Eluatwerte von Sb und V können jedoch durch Sorption an Eisenoxidverbindungen gemindert werden. Dazu wurden Sorptionsexperimente mit verschiedenen Eisenoxidverbindungen durchgeführt.
Neubewertung von metallenen Dach- und Fassadenmaterialien unter Dauerhaftigkeits- und Umweltaspekten
(2023)
Metallene Dach- und Fassadenmaterialien unterliegen nach ihrer Installation infolge von Korrosions- und Abschwemmprozessen einem Abtrag von Metallionen. Durch Regenereignisse gelangen diese in umliegende Gewässer und Böden. Die verwendeten metallenen Werkstoffe, wie z.B. Kupfer und Zink bilden zeitabhängig schützende Deckschichten aus, die die Dauerhaftigkeit der Werkstoffe gewährleisten und damit den Austrag von Metallionen signifikant begrenzen. Die Geschwindigkeit der Deckschichtbildung sowie die erreichte Schutzwirkung sind von verschiedenen Umwelteinflüssen und klimatischen Bedingungen abhängig. Diese haben sich in den letzten Jahrzehnten in Europa stark verändert, so dass es einer aktuellen Datenbasis für die Bewertung der Dauerhaftigkeit und der Umweltauswirkungen bedarf. Im Rahmen eines Forschungsvorhabens werden aktuell Feldstudien zur Ermittlung des Runoffs und der Schutzwirkung der gebildeten Deckschichten durchgeführt. Ergänzt werden diese durch Laborversuche mit künstlicher Beregnung.
Aschen und Schlacken aus der thermischen Abfallbehandlung enthalten eine Vielzahl von Schwermetallverbindungen. Für Antimon, Chrom, Kupfer, Molybdän und Vanadium werden in der neuen Ersatzbaustoffverordnung Eluatgrenzwerte für die Verwertung festgelegt. Aschen und Schlacken werden aus der Abfallverbrennungsanlage nass ausgetragen und vor einer Verwertung in der Regel mehrere Wochen gelagert. Dabei finden hydraulische Reaktionen statt und enthaltenes CaO wird zu einem Großteil in Calciumcarbonat umgewandelt. Während wässrige Eluate von frischen Aschen pH-Werte von 12 und höher aufweisen, sind die Eluate nach einigen Wochen weniger stark alkalisch. Die gemessenen Schwermetallkonzentrationen sind daher dann auch deutlich niedriger, mit Ausnahme von Antimon (Sb) und Vanadium (V). Hier steigen die Konzentration mit der Lagerungsdauer. Grund sind sinkende Konzentrationen von Ca-Ionen, die sonst zu einer Ausfällung von Antimonaten und Vanadaten führen. Zu hohe Eluatwerte von Sb und V können durch Sorption an Eisenoxidverbindungen gemindert werden. Als besonders wirkungsvoll hat sich Schwertmannit (Eisen-Oxyhydroxysulfat) erwiesen. Es entsteht durch Oxidation von pyrithaltigem Material durch Mikroorganismen und wird deshalb in Gebieten gefunden, in denen Braunkohle abgebaut wurde, z.B. in der Lausitz. Weitere untersuchte Eisenoxidverbindungen waren Hämatit und Schlämme aus der Abtrennung von Eisen und Mangan in Wasserwerken.
A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9-69% of spiked compounds using LC-HRMS and 20-60% of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participants’ own suspect lists led to putative identification of on average ~145 and ~20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ~42 and ~56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GC-HRMS). The compounds identified had log octanol/water partition coefficient (KOW) values ranging from -9.9 to 16 and mass-to-charge ratio (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples.
Neben Ressourceneinsparungen in der Produktion sorgen moderne Leichtbauwerkstoffe und -technologien für Energieeinsparungen in der Nutzungsphase. Auf diese Weise sowie als Enabler für eine Vielzahl an Zukunftstechnologien, wie zum Beispiel erneuerbare Energien, Elektromobilität und die Wasserstoffwirtschaft, ist Leichtbau fundamental für die Entkopplung des Wirtschaftswachstums vom Ressourcenverbrauch, die Erreichung der Ziele des Green Deals und eine Nachhaltige Zukunft. Um marktnahe Potentiale für Klima- und Ressourcenschutz vollständig zu heben und Herausforderungen wie die Kreislauffähigkeit im Leichtbau aktiv zu adressieren, fördert das BMWK marktnahe Innovationen im Leichtbau mit den Technologietransfer-Programm Leichtbau (TTP LB) Auch für die BAM bietet das TTP LB interessante Möglichkeiten, Forschungsvorhaben umzusetzen. Derzeit werden vier Projekte mit BAM-Beteiligung gefördert. In diesem Webinar stellen wir Ihnen die gesamte Breite des Leichtbaus vor und zeigen Ihnen damit direkte Anknüpfungspunkte zu Ihrer Forschung. Dafür wird das TTP LB vorgestellt, werden wertvolle Einblicke zur Antragstellung gegeben und der Weg zum Erfolg wird am Beispiel des BAM-Projektes SmartWeld skizziert. Neben der Erläuterung von technischen Details und formalen Anforderungen des Förderprogramms möchten wir ebenfalls versuchen, einen kleinen Ausblick auf mögliche zukünftige Entwicklungen zu geben.
Obwohl der Leichtbau mit carbonfaserverstärkten Kunststoffen (CFK) einen wichtigen Beitrag zum Klimaschutz und zur Ressourceneffizienz liefert, stellt der wachsende Abfallstrom von aktuell 62 kt/a eine große Herausforderung dar. Weil die Produktion von Carbonfasern (CF) überwiegend auf fossilen Rohstoffen basiert und sehr energieintensiv ist, werden nachhaltige Recyclinglösungen dringend benötigt.
Hier geben wir einen Überblick über aktuelle Recyclingprozesse und diskutieren deren Limitierungen. Darüber hinaus zeigen wir eine Möglichkeit zur sicheren chemischen Nutzung von CF-haltigen Reststoffen auf, die nicht zur Wiederverwertung geeignet sind. Das Projekt CF Pyro untersucht deren Einsatz als Sekundärrohstoff in der Pyrometallurgie und setzt besondere Schwerpunkte bei der Reaktivität von CF, der Prozessstabilität und der Vermeidung von Emissionen gesundheitsschädlicher WHO-Fasern. Neben der Vorstellung von wichtigen fundamentalen experimentellen Erkenntnissen wird ihre Bedeutung für den Wandel zum zirkulären Wirtschaften diskutiert.
The increasing use of carbon fiber reinforced polymers (CFRP), as lightweight materials essential for the transformation, demands for a safe treatment option of carbon fiber (CF) containing waste streams. Because of their low reactivity towards oxidation processes, CF can neither be treated in a conventional nor hazardous waste incineration plant. Even the extremely high temperature in a cement rotary kiln does not lead to full conversion. To increase the sustainability of CF, other processes need to be investigated. Opening other reaction pathways, using CF waste streams as secondary resource in pyrometallurgy to replace fossil carbon, can be a solution for a safe and sustainable treatment. To support the industrial application, experiments on different scales were conducted. Here, results of thermochemical investigations, reactivity studies, crucible experiments and pilot plat trials are reported.
The increasing use of carbon fiber reinforced polymers (CFRP), as lightweight materials essential for the transformation, demands for a safe treatment option of carbon fiber (CF) containing waste streams. Because of their low reactivity towards oxidation processes, CF can neither be treated in a conventional nor hazardous waste incineration plant. Even the extremely high temperature in a cement rotary kiln does not lead to full conversion. To increase the sustainability of CF, other processes need to be investigated. Opening other reaction pathways, using CF waste streams as secondary resource in pyrometallurgy to replace fossil carbon, can be a solution for a safe and sustainable treatment. After first small scale experiments, CF containing waste streams were used as reductant in a semi-industrial scale electric arc furnace (EAF). First results and impressions are presented.
Inputs of plastic impurities into the environment via the application of fertilizers are regulated in Germany and the EU by means of ordinances. Robust and fast analytical methods are the basis of legal regulations. Currently, only macro- and large microplastic contents (>1 mm) are measured. Microplastics (1–1,000 µm), are not yet monitored. Thermal analytical methods are suitable for this purpose, which can determine the mass content and can also be operated fully automatically in routine mode. Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS) allows the identification of polymers and the determination of mass contents in solid samples from natural environments. In accordance with the German or European Commission (EC) Fertiliser Ordinance, composting plants should be monitored for microplastic particles with this method in the future. In this context a compost plant was sampled. At the end of the rotting process, the compost was sieved and separated in a coarse (>1 mm) and a fine fraction (<1 mm). The fine fraction was processed using density separation comparing NaCl and NaI as possible salt alternative and screened for microplastic masses by TED-GC/MS with additional validation and quality assurance experiments. With TED-GC/MS total microplastics mass contents of 1.1–3.0 μg/mg in finished compost could be detected with polyethylene mainly. What differs much to the total mass of plastics in the coarse fraction with up to 60 μg/mg, which were visually searched, identified via ATR-FTIR and gravimetrically weighted.
Woodworms, carpet beetles, clothes moths and termites are well known pests on artifacts of cultural importance. Lately also silverfish have gained importance. Protection of our cultural heritage for future generations is not a new task but the methods have changed. Conventional use of pesticides in the past has preserved precious objects up to the presence, which otherwise probably would have been lost over time due to the destruction by insects and microbes. However, several of the objects were contaminated with poisons in such a manner that they became unsafe to be handled and thus are useless for exhibitions or scientific studies.
Today, the concept of Integrated Museum Pest Management (IMPM) provides guidance for non-residue treatments of infested objects, followed by save storage or display under pest free (or maximum pest reduced) environments. Inert fumigants, physical and biological control measure, precise monitoring, threshold evaluations and detailed knowledge of the pest`s biology are key elements within IMPM.
Woodworms, clothes moths and termites, however, are not always considered as only pests. Some professionals have also used them to produce new pieces of art or for the installation of ephemeral displays. Under more or less controlled conditions, the insects´ destructive nature on wood or textiles has been turned around to a process of creation with aesthetic or philosophical messages.
Destructive or creative - it just depends on the point of view!
Kunststoffdichtungsbahnen (KDB) aus PE-HD (Polyethylen hoher Dichte) werden häufig zur Abdichtung von Bauwerken in der Geotechnik verwendet. Diese Produkte werden aus einem Kunststoff mit relativ komplexer Zusammensetzung hergestellt. Um eine Aussage über die Haltbarkeit von KDB aus PE-HD treffen zu können, muss das Materialverhalten berücksichtigt werden. In diesem Zusammenhang sind die wichtigsten Aspekte der Dauerhaftigkeit die Spannungsrissbeständigkeit und die Beständigkeit gegen Oxidation. Verschiedene PE-Sorten weisen eine unterschiedliche Spannungsrissbeständigkeit auf. Um dieser Eigenschaft von PE-HD zu begegnen, werden nur KDB aus sehr hochwertigen Rohstoffen zugelassen. Auf der anderen Seite werden hohe Anforderungen an die umgebenden Schichten, wie Auflager und Schutzschicht gestellt, um möglichst geringe Spannungen zu erzeugen und damit Dehnungen die Dehnungen der KDB gering zu halten. Bestimmte Medien, die bei den betreffenden Prüfungen verwendet werden, dürfen nicht mehr in der EU in Verkehr gebracht werden. Im Folgenden sollen die Zusammenhänge in Kürze dargestellt werden.
Darüber hinaus sollen Diskussionen und Änderungen im Zusammenhang mit der Zulassungsrichtlinie für KDB vorgestellt werden. Der aktuelle Stand der Diskussion im Zusammenhang mit den verwendeten Tensiden in Bezug auf die Spannungsrissprüfung und weiterer Prüfungen wird aufgezeigt. Änderungen der Fremdprüfung von sogenannten Sandschutzmatten, des Standards zur Qualitätsüberwachung (SQÜ) von Kunststoff Dränelementen (KDE) und der Anpassung der Formulierungen zum Überbau der in Abdichtungen verwendeten Produkte werden in Kürze aufgezeigt.
Der Vortrag stellt den aktuellen Stand des Forschungsprojekts RUNOFF vor. Dabei liegt der Fokus auf die Neubewertung der Dauerhaftigkeit von Zink und feuerverzinktem Stahl. Unter bewitterten Bedingungen erreichen beide Materialien stabile, karbonathaltige Deckschichten bereits nach einer Auslagerungszeit von zwei Monaten. In den parallel zu den Feldversuchen laufende Laborversuche werden aktuell der Einfluss dreier Faktoren (Ph-Wert, Winkel des Probenmaterials, Niederschlagsintensität) auf das Abschwemmverhalten von Zinkionen mithilfe eines an der BAM konstruierten Niederschlagsimulators untersucht.
Kunststoffdichtungsbahnen (KDB) aus PE-HD (Polyethylen hoher Dichte) werden häufig zur Abdichtung von Bauwerken in der Geotechnik verwendet. Diese Produkte werden aus einem Kunststoff mit relativ komplexer Zusammensetzung hergestellt. Um eine Aussage über die Haltbarkeit von KDB aus PE-HD treffen zu können, muss das Materialverhalten berücksichtigt werden. In diesem Zusammenhang sind die wichtigsten Aspekte der Dauerhaftigkeit die Spannungsrissbeständigkeit und die Beständigkeit gegen Oxidation. Verschiedene PE-Sorten weisen eine unterschiedliche Spannungsrissbeständigkeit auf. Um dieser Eigenschaft von PE-HD zu begegnen, werden nur KDB aus sehr hochwertigen Rohstoffen zugelassen. Auf der anderen Seite werden hohe Anforderungen an die umgebenden Schichten, wie Auflager und Schutzschicht gestellt, um möglichst geringe Spannungen zu erzeugen und damit Dehnungen die Dehnungen der KDB gering zu halten. Bestimmte Medien, die bei den betreffenden Prüfungen verwendet werden, dürfen nicht mehr in der EU in Verkehr gebracht werden. Im Folgenden sollen die Zusammenhänge in Kürze dargestellt werden.
Darüber hinaus sollen Diskussionen und Änderungen im Zusammenhang mit der Zulassungsrichtlinie für KDB vorgestellt werden. Der aktuelle Stand der Diskussion im Zusammenhang mit den verwendeten Tensiden in Bezug auf die Spannungsrissprüfung und weiterer Prüfungen wird aufgezeigt. Änderungen der Fremdprüfung von sogenannten Sandschutzmatten, des Standards zur Qualitätsüberwachung (SQÜ) von Kunststoff Dränelementen (KDE) und der Anpassung der Formulierungen zum Überbau der in Abdichtungen verwendeten Produkte werden in Kürze aufgezeigt.
Das Recycling von gemischten Baustoffen führt neben der Herstellung von Gesteinskörnungen parallel zu einem stärker schadstoffbelasteten Stoffstrom, der circa ein Drittel der ursprünglichen Masse ausmacht. Dieser sogenannte Brechsand endet derzeit in der Deponierung und wird somit der Kreislaufwirtschaft entzogen. Der vorliegende Beitrag untersucht nun die Aufbereitung dieses Materials unter Verwendung einer Setzmaschine im Pilotmaßstab. Hierbei wird die Eignung dieser Technik evaluiert und das Aufbereitungsprodukt als möglicher Ersatzbaustoff untersucht.
Wir zeigen, dass bei homogenen ausgeprägt sandartigen Böden mit statistisch ermittelten Korrelationen die dynamischen Bodensteifigkeiten mit einer Genauigkeit abgeschätzt werden können, die mit der Ungenauigkeit der seismischen Verfahren übereinstimmt. Mit zunehmenden Feinkornanteil werden die Unsicherheiten der statistischen Korrelationen größer. Bei stark überkonsolidierten glazialen Böden sollte von der Anwendung empirischer Korrelationen Abstand genommen werden.
Despite the increasing concern about the harmful effects of micro- and
nanoplastics (MNPs), there are no harmonized guidelines or protocols yet available for MNP ecotoxicity testing. Current ecotoxicity studies often use commercial spherical particles as models for MNPs, but in nature, MNPs occur in variable shapes, sizes and chemical compositions. Moreover, protocols developed for chemicals that dissolve or form stable dispersions are currently used for assessing the ecotoxicity of MNPs. Plastic particles, however, do not dissolve and also show dynamic behavior in the exposure medium, depending on, for example, MNP physicochemical properties and the medium’s conditions such as pH and ionic strength. Here we describe an exposure protocol that considers the particle-specific properties of MNPs and their dynamic behavior in exposure systems. Procedure 1 describes the top-down production of more realistic MNPs as representative of MNPs in nature and particle characterization (e.g., using thermal extraction desorption-gas chromatography/mass spectrometry). Then, we describe exposure system development for short- and long-term toxicity tests for soil (Procedure 2) and aquatic (Procedure 3) organisms. Procedures 2 and 3 explain how to modify existing ecotoxicity guidelines for chemicals to target testing MNPs in selected exposure systems. We show some examples that were used to develop the protocol to test, for example, MNP toxicity in marine rotifers, freshwater mussels, daphnids and earthworms. The present protocol takes between 24 h and 2 months, depending on the test of interest and can be applied by students, academics, environmental risk assessors and industries.
Heterogeneous construction and demolition waste can be used as raw material to produce lightweight aggregates (LWA) similar to expanded clays. In the joint research project “REALight”, LWA were produced from masonry rubble in a thermal expanding process using a pilot production plant with a rotary kiln. Our research focuses on the characterisation of the novel LWA and their use in different hydraulically bound applications.
Infra-lightweight concrete (ILC) was produced with the novel LWA, which accounts for two thirds of total aggregate volume, and Celitement, which is a hydraulic binder with a low carbon footprint. Its dry bulk density is ≤ 800 kg/m³. Strength and durability properties are comparable to ILC data from the literature.
Lime-based repair mortars (LRM) containing LWA are beneficial for sandstone conservation due to their similar properties regarding porosity, water absorption and strength. A two-layer repair mortar system, which consists of a filling mortar to fill large voids and a covering mortar to modulate the surface texture to the historic sandstone, was developed.
In our contribution, we present results of the LWA characterisation according to the European standard EN 13055:2016. Requirements and challenges of the use of the novel LWA in ILC and LRM are discussed.
Melanins are organic pigments produced by most fungi. These organisms either fix these pigments in their cell wall or secrete them into their extracellular environment to protect themselves against an array of physicochemical stresses (e.g., UV irradiation, desiccation, ...). Melanin can adsorb metals like Fe. How this affects fungal uptake of Fe and deterioration of Fe-containing minerals and metals is however less known. To study this, we use the model fungi Knufia petricola A95, a rock-inhabiting fungus known to deteriorate minerals and have melanised cell walls, and Amorphotheca resinae, able to contaminate fuel tanks, secrete melanin and corrode metals. In K. petricola, we have deleted genes involved in melanin production and Fe uptake using CRISPR/Cas. Through comparison of the geochemical signatures of these gene deletion mutants with those of the wild type (WT), we explore the specific mineral/metal deterioration mechanisms of melanised fungi.
Fe isotope signatures of the biomass of melanin- and Fe uptake-deficient mutants of K. petricola revealed that Fe adsorbed either directly onto melanin or after being reduced by Fe reductases. Importantly, once adsorbed to melanin, Fe could not be mobilised and taken up into the cell: both the WT and its melanin-deficient mutant, previously grown at Fe replete conditions, showed similar growth at Fe deficient conditions.
Olivine dissolution experiments revealed that Fe oxidation inhibits dissolution. K. petricola was able to enhance dissolution when this inhibition is strongest (at pH 6) and prevented dissolution when this inhibition is weakest (at pH 4). The fungus therefore dissolves olivine by interacting with the oxidised Fe at the olivine surface. However, Fe uptake did not seem to be involved: mutants deficient in various Fe uptake mechanism dissolved olivine at the same rate as the WT. This indicates that Fe adsorption onto melanin might play a key role. This is also shown by K. petricola’s ability to enhance olivine dissolution even further if secreting a melanin precursor and A. resinae’s corrosion of carbon steel whilst secreting melanin. Combined, our results imply that the Fe adsorbed to melanin cannot be taken up but enables fungi to deteriorate Fe-containing substrates at a higher rate.
Steelmaking slag is a by-product of steel production of which 4.5 Mt were produced in 2020 in Germany alone. It is mainly used in road construction, earthwork and hydraulic engineering. A smaller part is returned to the metallurgical circle, used as fertilizer or landfilled.
With this use, iron oxides still contained in steelmaking slag are lost. In addition, the possibility of producing higher-grade products from steelmaking slag is foregone. In recent decades, many researchers have investigated the production of Portland cement clinker and crude iron from basic oxygen furnace slags (BOFS) via a reductive treatment. Carbothermal treatment of liquid BOFS causes a reduction of iron oxides to metallic iron, which separates from the mineral phase due to its higher density. Simultaneously, the chemical composition of the reduced slag is adapted to that of the Portland cement clinker.
In this study, German BOFS was reduced in a small-scale electric arc furnace using petrol coke as a reducing agent. The resulting low-iron mineral product had a similar chemical composition to Portland cement clinker and was rich in the tricalcium silicate solid solution alite (Ca3SiO5). Based on its chemical and mineralogical composition, similar to that of Portland cement clinker, the reduced BOFS has the potential to react comparably. In our study, the reduced BOFS produced less heat of hydration compared to OPC and its hydraulic reaction was delayed. However, adding gypsum has been shown to accelerate the hydration rate of the reduced BOFS compared to that known from the calcium silicates of Portland cement clinker.
Further research to improve the hydraulic properties of the reduced slag is essential. If successful, producing a hydraulic binder and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry.
Biocides are used for a wide range of purposes, including disinfectants or preservatives. They play a major role in the prevention of microbial infections in healthcare and animal husbandry. The use of biocides often leads to the discharge of active biocidal substances into wastewater streams, causing the exposure of wastewater microbial communities to subinhibitory concentrations. In turn, it is known that wastewater treatment plants (WWTP) are hotspots for antibiotic resistant bacteria. Since similar mechanisms confer resistance to biocides and antibiotics, exposure to biocides can result in co-selection of antibiotic resistant bacteria in WWTP Here, we want to investigate co-selection processes of antibiotic resistance in natural WWTP microbial communities upon biocide exposure. Microbial communities were sampled at the WWTP Ruhleben in Berlin and characterized regarding their susceptibility against different clinically relevant antibiotics. To investigate the link between biocide exposure and antibiotic resistance, changes in the susceptibility level after exposure to environmentally relevant concentrations of the commonly used biocide didecyldimethylammonium chloride (DDAC) will be determined by enumerating resistant and non-resistant E. coli on selective plates with and without antibiotics and DDAC. In case of antibiotics, clinical breakpoint concentrations according to EUCAST will be used to discriminate between susceptible and resistant strains. In case of DDAC (and biocides in general), clinical breakpoints do not exist. Therefore, we determined a cut-off concentration at which the majority of naturally-occurring E. coli strains cannot grow anymore based on (I) the MIC (minimal inhibitory concentration) distribution, and (II) by plating wastewater communities onto selective indicator agar plates loaded with increasing DDAC concentration. Additionally, antibiotic cross-resistance will be determined by spotting single colonies, isolated from DDAC-selective plates onto antibiotic plates. The results of our experiments will help to determine selective concentrations and to estimate the risk of antibiotic co-selection and cross-resistance in microbial WWTP communities upon biocide exposure.
Im Verbundprojekt R-Rhenania wird eine industrielle Demonstrationsanlage am Standort der Monoverbrennungsanlage Altenstadt der Firma Emter errichtet und im Jahr 2024 den Betrieb aufnehmen. Die vorhandene Rostfeuerung-Monoverbrennung wird so umgebaut, dass ein neues thermochemisches Verfahren integriert werden kann, welches hochwirksame und schadstoffarme Dünger produziert (bis zu 17.000 t/a). Die thermochemischen Produkte werden in Gefäß- und Feldversuchen im ökologischen Landbau auf ihre Düngewirkung getestet. Die Umweltverträglichkeit der Demonstrationsanlage wird untersucht, wie auch die Übertragbarkeit des Verfahrens auf weitere Regionen.
Background. Disinfection is an important mitigation strategy to control and prevent the spread of infections. Incomplete or incorrect usage of disinfection may promote evolution of resistance against disinfectants and antibiotics. Ideally, disinfection reduces the number of surviving bacteria and the chance for resistance evolution. Resistance describes the ability to grow in previously inhibitory concentrations of an antimicrobial, whereas tolerance is associated with enhanced survival of lethal doses. Individual bacteria from the same population can display considerable heterogeneity in their ability to survive treatment (i.e. tolerance) with antimicrobials, which can result in unexpected treatment failure.
Objective. In this study, we investigated six active substances of disinfectants, preservatives, and antiseptics against a population of E. coli to identify the presence of a tolerant subpopulation.
Methods. We performed time-kill experiments and analyzed the data with a mathematical model to statistically infer whether the data is best explained by the presence of a tolerant subpopulation.
Results. The analysis identified bimodal kill kinetics for benzalkonium chloride, didecyldimethylammonium chloride, and isopropanol. In contrast, kill kinetics by chlorhexidine, glutaraldehyde, and hydrogen peroxide were best explained by unimodal kill kinetics. These findings have implications for the risk of disinfection failure. In addition, we are currently performing adaptive laboratory evolution (ALE) experiments with the different disinfectants to investigate the potential consequences of tolerant sub-populations for the evolution of antimicrobial resistance and tolerance.
Background. Disinfection is an important mitigation strategy to control and prevent the spread of infections. Incomplete or incorrect usage of disinfection may promote evolution of resistance against disinfectants and antibiotics. Ideally, disinfection reduces the number of surviving bacteria and the chance for resistance evolution. Resistance describes the ability to grow in previously inhibitory concentrations of an antimicrobial, whereas tolerance is associated with enhanced survival of lethal doses. Individual bacteria from the same population can display considerable heterogeneity in their ability to survive treatment (i.e. tolerance) with antimicrobials, which can result in unexpected treatment failure.
Objective. In this study, we investigated six active substances of disinfectants, preservatives, and antiseptics against a population of E. coli to identify the presence of a tolerant subpopulation.
Methods. We performed time-kill experiments and analyzed the data with a mathematical model to statistically infer whether the data is best explained by the presence of a tolerant subpopulation.
Results. The analysis identified bimodal kill kinetics for benzalkonium chloride, didecyldimethylammonium chloride, and isopropanol. In contrast, kill kinetics by chlorhexidine, glutaraldehyde, and hydrogen peroxide were best explained by unimodal kill kinetics. These findings have implications for the risk of disinfection failure. In addition, we are currently performing adaptive laboratory evolution (ALE) experiments with the different disinfectants to investigate the potential consequences of tolerant sub-populations for the evolution of antimicrobial resistance and tolerance.
Surfaces of metallic copper and copper alloys effectively inactivate microorganisms and viruses. However, the exact inactivation mode is still under debate. Main factors are assumed to include direct contact with the metallic surface, influx of Cu(I)/Cu(II) ions and the generation of reactive oxygen species (ROS). Laser-induced periodic surface structures (LIPSS) are frequently reported to act antibacterial, mainly by prevention of bacterial adhesion due to a limited number of possible adhesion points or by increasing the overall surface of intrinsically antibacterial materials. In time-kill experiments with E. coli and S. aureus we analyzed the impact of LIPSS on the toxicity of metallic copper and brass. We also conducted ROS accumulation assays and conclude that the application of LIPSS is not generally straight forward to obtain or improve antibacterial surfaces. Thus, the antibacterial effects of LIPPS.
Generation of Cryomyces antarcticus mutants to explore the importance of DHN melanin for survival
(2023)
Cryomyces antarcticus, a cryptoendolithic melanized fungus endemic to Antarctica (phylum Ascomycota, class Dothideomycetes incertae sedis), has demonstrated high capability to survive extreme environmental conditions like those found in space (e.g., ionizing radiation, vacuum, microgravity), thus fueling fundamental astrobiological questions like “the search for life beyond Earth”. Its extraordinary resilience has been attributed to the presence of thick, highly melanized cell walls, which may contain both DHN and DOPA melanins. To better understand the contribution of DHN melanin to the overall resilience of C. antarcticus, we decided to generate melanin-deficient mutants by genetic engineering. For this, the melanin-PKS (polyketide synthase)- encoding ortholog was identified in the C. antarcticus CBS 116301 genome and used to design primers for re-sequencing of the capks1 locus in the strain CCFEE 515. Based on the genetic toolkit developed for the black fungus Knufia petricola, we designed a strategy for mutating capks1. Protoplasts of C. antarcticus CCFEE 515 were generated and co-transformed with a circular AMA-containing plasmid for expression and in-vivo assembly of Cas9 and two capks1-specific sgRNAs and a PCR-generated donor DNA i.e., a hygromycin resistance cassette flanked by ~75-bp-long sequences homologous to the capks1 locus. Transformation of C. antarcticus is challenging because of its very slow growth and uncertain gene copy number. It took six months from obtaining enough biomass for cell wall lysis to transferring the putatively resistant transformants for genotyping, but we eventually managed to generate three independent non-melanized (whitish) Δcapks1 mutants! We are now awaiting first complemented strains as ultimate genetic transformation control. They are considered to have a wild-type-like pigmentation due to the reintroduction of the wild-type capks1 into the Δcapks1 mutant.
Bacteria are ubiquitous and colonize all types of surfaces, including those in close proximity to humans, such as skin, food, and everyday objects. This raises the question of whether their presence represents a problem to be mitigated or a potential source of benefit to be harnessed, thereby stimulating scientific inquiry into the role of surface-associated bacteria in diverse domains ranging fromhuman health to industrial biotechnology. Aim: The objective of this project is to explore the impact of modifying surface topography on bacterial adhesion behavior. By manipulating the physical characteristics of the substrate, the attachment and detachment dynamics of bacteria can potentially be modified, leading to novel strategies for controlling bacterial colonization in various applications, such as medical devices. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested on LIPSS-covered Fused Silica samples.
Human-made systems, also called “build environment” or “technosphere”, sustain human comfort as well as our industrial activities. These systems have become particularly widespread since the Industrial Revolution, i.e., since the 17th century. At the same time, these technical systems – buildings, monuments, energy production, transformation and transmission, water purification and supply systems - serve as new habitats for living organisms.
Life is ubiquitously present on our planet since a very long time: the Earth is 4.54 billion years old and microbial communities have played a key role on our planet for 3.7 billion years. Once human-made system appeared, microorganisms became an integral part of all types of technosphere infrastructure as well.
Here we will illustrate biosphere-technosphere interactions using a specific example of the black fungi and their impact on the efficiency of solar (photovoltaic) panels. This expanding renewable infrastructure for electricity generation is growing on all continents - and create a specific, arid habitat for stress-tolerant black fungi.
Black fungi were once discovered in hot and cold natural deserts – and now belong to the persistent colonisers of human-made deserts of solar parks. This new niche is evolving an impressive biodiversity. So far more than 60 isolates of black fungi belonging to Arthoniomycetes, Eurotiomycetes and Dothideomycetes were obtained from solar panels in Europe and Americas. Here we will present the analysis of this emerging anthropogenic biodiversity.
Opportunities for future research in the field include quantification of the microbial load on technosphere surfaces – along with characterisation of the corresponding microbial diversity. The strategy of precise measurement and characterisation will enable us to reliably determine the beneficial and harmful functions that living microorganisms play in the functioning of energy-generating systems – and technosphere in general.
This presentation was held in an OECD Webinar introducing the newly developed and published OECD TG 125 on particle size and size distribution. The presentation is explaining the structure if the TG 125 and addresses all included methods and methodologies in a short and understandable way for the broader public. The presentation includes sections about nano-particles and nano-fibres.
Each year, an immense amount of plastic debris enters marine ecosystems, much of which ends up in the Great Pacific Garbage Patch (GPGP). The plastic fragments are home to a diverse community of microorganisms, and while researchers have gained a better understanding of these marine plastic biofilms, we lack insights into the physiology and genomic potential of the bacteria that colonize them. Examining the lifestyle of plastic colonizers from the GPGP is particularly intriguing, as the high concentration of plastics in this accumulation zone might allow for a microbial adaptation to this unique man-made habitat. A range of pigmentation was observed in 67 isolated strains obtained directly from plastic pieces sampled from the GPGP surface water. Sequence comparison between the cultivated bacterial strains and the 16S rRNA gene amplicon dataset confirmed that most of the cultivates could also be captured through DNA-only methods. Whole genome analysis of four taxonomically diverse representatives revealed multiple carotenoid pathways, including those to produce less common glycosylated carotenoids, like sarcinaxanthin glucoside. Further, we identified a potentially new Rhodobacteraceae species containing a photosynthetic gene cluster (PGC). Absorption analysis confirmed the actual production of the carotenoids and bacteriochlorophyll a. Floating plastics represent a habitat with strong UV-light exposure, making the protection with antioxidant carotenoids as well as the ability to use light as an energy source highly beneficial traits for plastic colonizers. Our findings indicate, that the production of pigments is a common adaption mechanism for plastic-associated bacteria, and that plastic biofilms present a so far overlooked source of rare carotenoids and light-harvesting mechanisms.
Glutaraldehyde (GTA) is commonly used to disinfect medical equipment, in animal husbandry and in hydraulic fracturing. Its wide use bears the risk that microorganisms in different environments are exposed to potentially non-lethal doses of glutaraldehyde. To date, little is known about the effects of glutaraldehyde on the susceptibility of bacteria to antibiotics and its role in the selection of tolerant phenotypes.
Objectives
• To determine the effect of glutaraldehyde exposure on the survival of E. coli, S. aureus and P. aeruginosa to antibiotics
• To find the mechanistic basis for antibiotic tolerance upon glutaraldehyde exposure
Materials & Methods
Four bacterial isolates were exposed to sub-inhibitory glutaraldehyde. Antibiotic tolerance was determined by time-kill assays. Regrowth dynamics (lag times) were determined with ScanLag. E. coli was further investigated, using RNAseq to identify genes and processes involved in antibiotic tolerance. Mutants of candidate genes were screened for their antibiotic tolerance and heterogeneous target gene expression under stressed and unstressed conditions.
Results
Short-term exposure to sub-inhibitory levels of glutaraldehyde induced tolerance to high doses of bactericidal antibiotics. Tolerance to antibiotics was associated with highly heterogeneous regrowth dynamics and global transcriptome remodeling. Differentially expressed genes represented diverse biological functions and cellular components, including antibiotic efflux, metabolic processes, and the cell envelope. The heterogeneous regrowth dynamics and the diversity of the differentially expressed genes are likely related to the unspecific mode-of-action of glutaraldehyde. Among the many differentially expressed genes, several genes were identified that were not previously associated with antibiotic tolerance or persistence, which, when overexpressed alone, increased antibiotic tolerance.
Conclusion
Our results highlight how the big advantage of a disinfectant, its unspecific mode-of-action, can induce transient tolerance to antibiotics in bacteria. These findings have implications for 1.) settings where disinfectants and antibiotics are used in proximity, such as hospitals and animal husbandry, and 2.) for the selection dynamics of tolerant bacteria in fluctuating environments because of the trade-off that arises from overcoming the lag phase as fast as possible and maintaining antibiotic tolerance.
Fungal biofilms on materials: describing and modelling growth of the black fungus Knufia petricola
(2023)
Fungi that grow as biofilms are associated with clinical settings as well as various cases of material fouling and material damage. Black fungi as biofilm formers have been rarely studied so far. Their conspicuous dark pigmentation, EPS production, adhesion capabilities and adaptations to stresses allow black fungi to develop biofilms on materials under harsh conditions. For example, rock-inhabiting black fungi withstand sun irradiation and dehydration and are therefore ubiquitous on arid surfaces like solar panels and marble monuments.
To understand and control their ability to colonise and deteriorate materials, one should assess and model black fungi’s growth patterns. But so far, no mathematical model has been developed to describe their growth. Knufia petricola A95, representing rock-inhabiting fungi from Chaetothyriales, is genetically amenable and can serve as a model for biofilm studies in black fungi. The primary objective of this project is to develop a growth model for K. petricola A95 which will enable to define and predict material colonisation of black fungi.
Dedicated experimental work with K. petricola will allow the quantitative assessment of the impact of environmental conditions (e.g. pH, nutrients, etc.) on the growth behaviour at the biofilm and single cells level. Data which will be used to validate and develop an individual-based model (based on the iDynoMICS modelling platform) that explains how fungal biofilms form, colonise materials, and cause deterioration.
Thus far, research has been conducted on the impact of different concentrations and sources of major elements (e.g. C, N, …), as well as trace elements (e.g. Cu, Mg, …), on the colony shape and biomass of Knufia petricola A95 biofilms. To study the behaviour of single cells, the length of the cell cycle in different growth media has been determined via the combined use of microfluidic devices and confocal microscopy.
The exponential rise in the number of fungal genomes sequenced by next-generation sequencing techniques makes it necessary to increase efforts to correctly annotate and assign gene functions. There are two possibilities to explore a genome and its gene functions. The hypothesis-based method proves the function of already existing gene/allele candidates by targeted mutagenesis - so called reverse genetics. The basis of forward genetics approaches is the random mutagenesis of the genome, followed by screening of obtained mutants for the phenotype of interest, and identification of the mutated genes in the respective mutants. This strategy is hypothesis-generating, means it is necessary to verify the relationship between the detected mutations and the observed phenotype by targeted mutagenesis of the identified gene. We developed a toolbox for editing the genome of the rock inhabitant Knufia petricola [Eurotiomycetes, Chaetothyriales] that allows the study of the phenotypic characteristics of black fungi such as the regulation of pigment synthesis, general stress responses, oligotrophy, and the unusual modes of cell division by advanced reverse and forward genetics approaches. The toolbox includes the annotated genome sequence of strain A95, efficient strategies for CRISPR/Cas9-based genome editing and live-cell imaging using genetically encoded fluorescent proteins, as well as protocols for -omics approaches and for simulation of mineral weathering. A forward genetics approach using transposon mutagenesis is currently developed for identifying essential genes. The established protocols and knowledge gained from K. petricola form a starting point for making other fungi from extreme environments accessible to genetic manipulation.
Dihydroxynaphthalene (DHN) melanin is produced by diverse Ascomycetes via slightly differing biosynthetic routes. The polyketide synthases (PKS) release the heptaketide YWA1, the hexaketide AT4HN or the pentaketide T4HN. The first two products are deacetylated by ‘yellowish-green’ hydrolases to T4HN, and T4HN is further converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases. DHN melanogenesis is often regulated in a spatial and temporal fashion resulting e.g., in melanized reproduction and survival structures of the foliar plant pathogen Botrytis cinerea (Schumacher 2016, Mol Microbiol). In contrast, a polyphyletic group of Ascomycetes (microcolonial fungi/ black yeasts) dwelling in hostile habitats such as bare rock surfaces in hot and cold deserts, exhibits constitutive melanogenesis. Here, DHN melanin builds a protective layer around all vegetative cells thus contributing to the survival of diverse environmental stresses even without specialized reproduction structures. For studying the relevance of constitutive DHN melanogenesis for tolerance of abiotic and biotic stresses, adhesion to substrates and subsequent damage of colonized surfaces, the rock-inhabiting fungus Knufia petricola was chosen as gene functions in this fungus can be studied by CRISPR/Cas9-based genome editing. The putative melanogenic genes were identified in the genome of K. petricola, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Phenotypes of DHN-deficient mutants are studied. Here, we will discuss the role of the DHN melanin layer on the outer cell wall in tolerating UV irradiation.
Dihydroxynaphthalene (DHN) melanin is produced by diverse Ascomycetes via slightly differing biosynthetic routes. The polyketide synthases (PKS) release the heptaketide YWA1, the hexaketide AT4HN or the pentaketide T4HN. The first two products are deacetylated by ‘yellowish-green’ hydrolases to T4HN, and T4HN is further converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases. DHN melanogenesis is often regulated in a spatial and temporal fashion resulting e.g., in melanized reproduction and survival structures of the foliar plant pathogen Botrytis cinerea (Schumacher 2016, Mol Microbiol). In contrast, microcolonial black fungi exhibit constitutive melanogenesis. Here, DHN melanin builds a protective layer around all vegetative cells thus contributing to the survival of diverse environmental stresses even without specialized reproduction structures. For studying the regulation and relevance of DHN melanogenesis for tolerance of abiotic and biotic stresses, adhesion to substrates and subsequent damage of colonized surfaces, the rock-inhabiting fungus Knufia petricola was chosen as gene functions in this fungus can be studied by CRISPR/Cas9-based genome editing. The putative melanogenic genes were identified in the genome of K. petricola, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Phenotypes of deletion mutants are studied for specifying the functions of DHN melanin in K. petricola.
Mobile proximal gamma-ray spectrometry (GS) is an emerging approach to estimate soil texture directly in the field. It relies on gamma radiation emitted during the natural decay of potassium-40 (K-40) and other isotopes. The K-40 counts are correlated with total K content, mineralogical soil composition and therefore with soil texture. Yet, it is not clear if K fertilisation impacts the ratio of K-40 to total K which would necessitate to take the fertilisation history into account for soil sensing applications. To elucidate this question, a well-documented long-term experiment was selected. The soils of the Rengen grassland experiment (55 plots) were investigated for total K (XRF-K) and for K-40 via mobile proximal GS. No significant differences in XRF-K and K-40 were found between the treatments with and without K fertilisation, although formely published results point to negative and positive K balances, respectively. Fertiliser analysis revealed a ratio of K-40 to total K that was almost identical to the natural abundance of 0.0117%. It was concluded that it is not necessary to take K fertilisation history into account when predicting soil texture from mobile proximal GS on agricultural land for, e.g., precision farming purposes.
Sustainable product policy is one pillar of the European Green Deal and the Circular Economy Action Plan. The European Commission is to begin to address recycling, recycled content and repair under the Ecodesign Directive and very likely in the announced European Sustainable Products Regulation. In addition, initiatives on recyclability and other aspects of sustainable products can be observed in France under the Ecomodulation Approach for some electrical and electronic products. Neither the Commission's ambitions nor the Ecomodulation Approach have so far led to a crucially better ecodesign of products.
Therefore, at the EU level, indices for reparability (already developed for smartphones and tablets), recyclability and recycled content of products are being discussed within the Ecodesign legislative framework in an attempt to achieve better ecodesign through advanced consumer purchasing decisions. The product standards requested by the European Commission to assess the recyclability (EN4555) and recycled content (EN4557) of energy-related products have already been published, but are purely based on a mass-based approach. Material-specific aspects such as the environmental impact or the financial, technical and redesign efforts required by manufacturers to facilitate the recycling and use of recycled materials are not addressed. Materials that are easy to recycle and use and have a high recycled content, such as copper, are treated in the same way as plastics that are difficult to recycle and use in products as post-consumer recycled plastics. Including such aspects would be essential to trigger environmentally relevant and significant improvements in product design.
Der Vortrag fasst die Schnittmenge zwischen Normung und Politik bezüglich einer zirkulären Wirtschaft (Circular Economy) zusammen. Es wird an konkreten Schlüsselgremien und praktischen Beispielen gezeigt, wie Circular Economy bereits heute durch Normung gelingen kann und welche Zuarbeit durch die Politik von den Normungsgremien erbeten wird.
Understanding the fundamentals of bioreceptivity enables the developement of functionalized materials. Concrete as the most used building material worldwide is of special interest as microbially greened panels may represent an alternative to classic façade greening with plants.
As standards are not ye established, material characterization in context as well as bioreceptivity assessment itself has been proven to be difficult. The presentation reviews first results of methods adapted for this application.
Over the past century, a range of synthetic compounds have been produced to improve humanity’s quality of life. These include pharmaceuticals, plastics, and other chemical compounds that possess properties making them potentially harmful when released to the environment (e.g., ecological and health impacts to humans and animals). Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals used in the formulations of thousands of consumer goods, including aqueous film-forming foams used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment, and plastic and leather products. Because of the recent regulations and restrictions on the use of long chain (≥C8) PFAS a significant shift in the industry towards short (C4-C7) and ultrashort (C1-C3) chain alternatives has been recognized the last years. Due to the high polarity and water solubility of ultrashort PFAS, the potential for bioaccumulation is low. However, the high persistence of ultrashort-chain PFAS will result in environmental accumulation, especially in aquatic environments, leading to potential risks for aquatic organisms and increased human external exposure through drinking water. Ultrashort PFAS like trifluoroacetic acid (TFA) are low to moderately toxic to a range of organisms. In addition, ultrashort PFAS can penetrate natural and anthropogenic barriers and eventually reach drinking water sources. Because common drinking water treatment techniques do not sufficiently remove them, they may reach human consumption. In the project we are focusing on detecting and removing PFAS, especially ultrashort-chain PFAS from contaminated groundwater. We are designing passive sampling devices, which can collect and monitor the temporal profile of PFAS species in groundwater. This will allow us to analyze PFAS contaminations in German and Israeli groundwater using state-of-the-art and novel analytical techniques and understand the extent of contamination. In addition to quantification, PFAS contaminated groundwater will be treated via a two-stage process to produce PFAS-free drinking water. As ultrashort-chain PFAS are difficult to analyze with the current target (LC-MS/MS) and sum parameter (AOF, EOF) analysis methods, we additionally using gas chromatography – mass spectrometry (GC-MS). Therefore, an analytical method based on GC-MS is in development to analyze the volatile ultrashort-chain PFAS (TFA, PFPrA, TFMS, PFEtS, PFPrS, trifluoroethanol, pentafluoropropanol and hexafluoro isopropanol) directly in contaminated groundwater samples with the headspace technique and in eluates of organic solvents from the developed passive sampler after direct injection. Moreover, a two-stages process is designed to increase the low concentrations found in groundwater using novel membranes processes such as closed-circuit reverse osmosis (CCRO) and mixed matrix composite nanofiltration membranes (MMCM). Next, the rejected streams containing higher concentrations of PFAS will be treated by coagulation, and the remaining PFAS adsorbed onto carbonaceous nanomaterials (CNMs). The DEFEAT-PFAS project will result in the development of novel tools to detect, quantify, and remove PFAS, especially ultrashort-chain PFAS from contaminated groundwater, and will acquire a new understanding of the extent of these contaminations.
Per- and polyfluoroalkyl substances (PFAS) are chemicals which were developed to improve humanity’s quality of life. Due to their high chemical stability and resistance to degradation by heat or acids, PFAS were used in a variety of consumer products. The continuous use of PFAS in household products and the discharge of PFAS from industrial plants into the sewer system resulted in the contamination of effluents and sewage sludge from wastewater treatment plants (WWTPs) (Roesch et al. 2022). Since sewage sludge is often used as fertilizer, its application on agricultural soils has been observed as a significant entry path for PFAS into the environment, specifically in our food chain. In Germany the sewage sludge/biosolid application on agricultural land was banned with the amendment of the German Sewage Sludge Ordinance and by 2029 sewage sludge application will be totally prohibited. However, phosphorus (P) from sewage sludge should still be recycled in WWTPs of cities with a population larger than 50,000 residents. To produce high-quality P-fertilizers for a circular economy, PFAS and other pollutants (e.g. pesticides and pharmaceuticals) must be separated from sewage sludge. Due to the strong diversity of industrial PFAS usage it is not clear if a safe application of novel recycled P-fertilizers from WWTPs can be guaranteed. Therefore, we analyzed various sewage sludges and wastewater-based fertilizers. Sewage sludge (SL) samples from various WWTPs in Germany and Switzerland, six sewage sludge ashes (SSA) from Germany, six thermally treated SL and SSA samples with different additives (temperatures: 700-1050 °C), two pyrolyzed SL samples (temperature: 400 °C) and two struvite samples from Germany and Canada were analyzed. The goal was to quantify PFAS in sewage sludges and wastewater-based P-fertilizers with the sum parameter extractable organic fluorine (EOF) by combustion ion chromatography (CIC). The results were compared with data from classical LC-MS/MS target analysis as well as selected samples by HR-MS suspect screening. The EOF values of the SLs mainly range between 154 and 538 µg/kg except for one SL which showed an elevated EOF value of 7209 µg/kg due to high organofluorine contamination. For the SSA samples the EOF values were lower and values between LOQ (approx. 60 µg/kg) and 121 µg/kg could be detected. For the pyrolyzed SLs no EOF values above the LOQ were detected. Moreover, the two wastewater-based struvite fertilizers contain 96 and 112 µg/kg EOF, respectively. In contrast to the EOF values, the sum of PFAS target values were relatively low for all SLs. Additional applied PFAS HR-MS suspect screening aimed to tentatively identify PFAS that could contribute to the hitherto unknown part of the EOF value. The majority of the detected fluorinated compounds are legacy PFAS such as short- and long-chain perfluorocarboxylic acids (PFCA), perfluorosulfonic acids (PFSA), polyfluoroalkyl phosphate esters (PAPs) and perfluorophosphonic acids (PFPA). Moreover, fluorinated pesticides, pharmaceutical as well as aromatic compounds were also identified, which are all included in the EOF parameter. Our research revealed that the current PFAS limit of 100 µg/kg for the sum of PFOS + PFOA in the German Fertilizer Ordinance is no longer up to date. Since the number of known PFAS already exceeds 10,000, the ordinance limit should be updated accordingly. Recent regulations and restrictions on using long-chain PFAS (≥C8) have resulted in a significant shift in the industry towards (ultra-)short-chain alternatives, and other, partly unknown, emerging PFAS. Ultimately, also fluorinated pesticides and pharmaceuticals, which end up as ultrashort PFAS in the WWTPs, have to be considered as possible pollutants in fertilizers from wastewater, too.
Solid wastewater-based fertilizers were screened for per- and polyfluoroalkyl substances (PFAS) by the extractable organic fluorine (EOF) sum parameter method. The EOF values for ten sewage sludges from Germany and Switzerland range from 154 to 7209 mg kg−1. For thermal treated sewage sludge and struvite the EOF were lower with values up to 121 mg kg−1. Moreover, the application of PFAS targeted
and suspect screening analysis of selected sewage sludge samples showed that only a small part of the EOF sum parameter values can be explained by the usually screened legacy PFAS. The hitherto unknown part of EOF sum parameter contains also fluorinated pesticides, pharmaceutical and aromatic compounds. Because these partly fluorinated compounds can degrade to (ultra-)short PFAS in wastewater treatment plants they should be considered as significant sources of organic fluorine in the environment. The combined results of sum parameter analysis and suspect screening reveal the need to update current regulations, such as the German fertilizer ordinance, to focus not solely on a few selected PFAS such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) but
consider an additional sum parameter approach as a more holistic alternative. Moreover, diffusion gradient in thin-films (DGT) passive samplers were utilized as an alternative simplified extraction method for PFAS in solid wastewater-based fertilizers and subsequently quantified via combustion ion chromatography. However, the DGT method was less sensitive and only comparable to the EOF values
of the fertilizers in samples with >150 mg kg−1, because of different diffusion properties for various PFAS, but also kinetic exchange limitations.
The phylogeny of the Blattodea boasts a wide degree of sociality spanning from solitary cockroaches to advanced ecosystem-dominating higher termite societies. The emergence of sociality in the termites was associated with the acquisition of a diverse range of social structures and differential expression of specific gene network. Previous work has found evidence for a caste-specific social defence system in termites leading to an immune system that may favour group over individual defence. While preliminary work suggests a correlation between social transitions and a reduction of immune gene family diversity, the lack of available high-quality termite genomes hampers complete knowledge of the true diversity of immune gene evolution across termite phylogeny. Here, we report on the sequencing and assembly of 50 high-quality long-read-based genomes and 180 caste- and sex-specific brain transcriptomes across major termite and cockroach sister-branch lineage. We investigate the diversity and evolutionary history of immune genes across genomes, and the potential gene networks that have evolved with the emergence of termite sociality and some aspect of immune related behaviours.
Adipokinetic hormone (AKH) is a neuropeptide produced in the insect corpora cardiaca that plays an essential role in mobilizing carbohydrates and lipids from the fat body to the hemolymph. AKH acts by binding to a rhodopsin-like G protein-coupled receptor (GPCR), the adipokinetic hormone receptor (AKHR). In this study, we tackle AKH ligand and receptor gene evolution as well as the evolutionary origins of AKH gene paralogues from the order Blattodea (termites and cockroaches). Phylogenetic analyses of AKH precursor sequences point to an ancient AKH gene duplication event in the common ancestor of Blaberoidea, yielding a new group of putative decapeptides. In total, 16 different AKH peptides from 90 species were obtained. Two octapeptides and seven putatively novel decapeptides are predicted for the first time. AKH receptor (AKHRs) sequences from 18 species, spanning solitary cockroaches and subsocial woodroaches as well as lower and higher termites, were subsequently acquired using classical molecular methods and in silico approaches employing transcriptomic data. Aligned AKHR open reading frames revealed 7 highly conserved transmembrane regions, a typical arrangement for GPCRs. Phylogenetic analyses based on AKHR sequences support accepted relationships among termite and cockroach lineages to a large extent, while putative post-translational modification sites do not greatly differ between solitary and subsocial roaches and social termites. This study provides important information not only for AKH and AKHR functional research but also for further analyses interested in their development as potential candidates for biorational pest control agents against invasive termites and cockroaches.
Insecta is one of the most diverse phyla in the animal kingdom, with species living in all types of habitats encountering an even greater diversity of pathogens and parasites. Defence strategies against such harmful threats led to a variety of molecular mechanisms, ecological shifts, and genetic innovations. Gene families underlying the molecular basis of the immune responses have evolved within the boundaries given by the species ecology. Here, we explore the evolution of some emblematic immune gene families throughout the Insecta phylum shedding light on remarkable genetic events such as gene duplication or gene loss. We followed a workflow based on the Hidden Markov model to search for immune genes in 55 high-quality genomes of insects. We highlight the emergence of group defence in social species as an ecological shift that released selection pressure on immune gene families notably in Blattodea. Further, we draw attention to certain gene families and the link between their diversity and the specificities of the species’ microbiota. Overall, we report data on immune gene diversity in insects.
Harnessing near-chromosome level quality genomes to explore the evolution of termite immunity
(2023)
The phylogeny of the Blattodea boasts a wide degree of sociality spanning from solitary cockroaches to advanced ecosystem-dominating higher termite societies. The emergence of sociality in termites was associated with the acquisition of a diverse range of social structures. Previous work has found evidence for a caste-specific social defence system in termites leading to an immune system that may favour group over individual defence. While preliminary work suggests a correlation between social transitions and a reduction of immune gene family diversity, the lack of available high-quality termite genomes hampers complete knowledge of the true diversity of immune gene evolution across termite phylogeny. Here, we report on the sequencing and near-chromosome level assembly of 48 high-quality long-read-based genomes across major termite and cockroach sister-branch lineages. We investigate the diversity and evolutionary history of immune genes across genomes, focusing particular attention on correlations between immune gene evolution and transitions in sociality over termite phylogeny.
The accelerating climate crisis results in a rising demand for ecologically driven concepts. Regarding construction, this does not only include environmentally friendly materials but also the establishment of greenery in urban regions.
This contribution presents the progress of two projects in which textured concrete slabs were designed to grow a stable biofilm of photosynthetic eukaryotic organisms. The greened panels represent an alternative to classic fa9ade greening with plants. Current literature suggests that the development of bioreceptive surface materials in the construction sector is difficult because there are no standardized methodological approaches for measuring said bioreceptivity. Therefore, the long-term. ahn is proposing a suitable measurement concept combining material Science and biology. Among other things, the intrinsic Substrate property pH value is expected to have a significant influence on biological colonization. In the current contribution the focus lies on the theoretical approach and design of experiment regarding this parameter.
Available experimental data will be presented.
Gene-V protein (G5P/GVP) is a single-stranded (ss)DNA-binding protein (SBP) of bacteriophage f1 that is required for DNA synthesis and repair. In solution, it exists as a dimer that binds two antiparallel ssDNA strands with high affinity in a cooperative manner, forming a left-handed helical protein–DNA filament. Here, we report on fluorescence studies of the interaction of G5P with different DNA oligonucleotides having a hairpin structure (molecular beacon, MB) with a seven base-pair stem (dT24-stem7, dT18-stem7), as well as with DNA oligonucleotides (dT38, dT24) without a defined secondary structure. All oligonucleotides were end-labeled with a Cy3-fluorophore and a BHQ2-quencher. In the case of DNA oligonucleotides without a secondary structure, an almost complete quenching of their strong fluorescence (with about 5% residual intensity) was observed upon the binding of G5P. This implies an exact alignment of the ends of the DNA strand(s) in the saturated complex. The interaction of the DNA hairpins with G5P led to the unzipping of the base-paired stem, as revealed by fluorescence measurements, fluorescence microfluidic mixing experiments, and electrophoretic mobility shift assay data. Importantly, the disruption of ssDNA’s secondary structure agrees with the behavior of other single-stranded DNA-binding proteins (SBPs). In addition, substantial protein-induced fluorescence enhancement (PIFE) of the Cy3-fluorescence was observed.
Per- and polyfluoroalkyl substances (PFAS) are a large, ever-growing and widely used class of chemicals. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment.
In recent years, many ‘hot spot’ sites with high PFAS contaminations in soil have been distinguished, but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions.
Due to the complexity and variety of different PFAS compounds, one needs to apply a broad spectrum of different techniques to capture most of the PFAS content in one sample.
In the framework of this project, 600 soil samples are taken at different sites all over Germany. The concentration of 30 PFAS - 13 carboxylic acids (C4-C18), 5 sulfonic acids (C4-C10) and 12 precursor substances) - is determined in these soil samples using three different sample preparation approaches: 1) ultrasonic extraction of the soil samples with Methanol; 2) preparation of eluates to test the leaching behaviour of the PFAS and 3) TOP assays following the method published by Houtz & Sedlak.
Targeted LC-MS/MS is used to determine PFAS concentration after all three preparation steps.
For the TOP-assay, the concentration of all 30 PFAS is compared prior to and after the oxidation reaction.
Besides the ‘classic’ TOP-Assay, two other TOP-Assay approaches, the dTOP Assay and the photoTOP-Assay, are tested and the results of all three approaches are compared. First, all three TOP-Assay approaches will be tested on a reference soil spiked with a solution including all 30 PFAS measured in the project. Later, soil samples taken in the frame of the priorly described project will be tested.
This poster will focus on the results of the experiments comparing the three different TOP Assay approaches in spiked reference soil. Additionally, some of the results of the other sample preparation methods, extraction and eluate preparation will be presented.
Fused filament fabrication (FFF) on desktop 3D printers is a material extrusion-based technique often used by educational institutions, small enterprises and private households. Polymeric filaments are melted and extruded through a heated nozzle to form a 3D object in layers. The extrusion temperature is therefore a key parameter for a successful print job, but also one of the main driving factors for the emission of harmful air pollutants, namely ultrafine particles and volatile organic gases, which are formed by thermal stress on the polymeric feedstock. The awareness of potential health risks has increased the number of emission studies in the past years. However, the multiplicity of study designs makes an objective comparison of emission data challenging because printer hardware factors such as the actual extruder temperature (TE) and also feedstockspecific emissions are not considered. We assume that across the market of commercial low- and mid-price FFF printers substantial deviations between actual and set extruder temperatures exist, which have a strong effect on the emissions and hence may bias the findings of exposure studies. In our last publication, we presented a standardized feedstock-specific emission test method and showed that for each investigated feedstock an increase in actual extruder temperature was accompanied by an increase in particle emissions (Tang and Seeger, 2022). Therefore, any systematic discrepancy between set and actual extruder temperature matters. In this study, we used a thermocouple and an infrared camera to measure the actual extruder temperatures at different heights. We found significant under- and overestimation of the actual extruder temperatures by the respective set temperatures in three commercial printers. This caused a broad variation of the measured total numbers of emitted particles (TP), even when the same feedstock was operated. For the determination of TP, we followed the DE-UZ 219 test guideline. In a second round we repeated the tests with all printers adjusted to exactly the same extruder temperatures, i.e., to TE=230°C for ABS and TE=210°C for PLA. All measurements were conducted in a 1 m³ emission test chamber. Particle emissions in the size range between 4 nm and 20 μm were detected. Printing on three different printer models without temperature adjustment resulted for each of the investigated feedstocks in a variation in TP of around two orders of magnitude. After temperature adjustment, this was substantially reduced to approx. one order of magnitude and hence minimizes the bias of printer hardware on the emissions. Our findings suggest that adjustment of the extruder temperature should be mandatory in emission testing standards. It also poses a more accurate benchmark and provides more reliable emission data for evaluation of indoor air quality or for health risk assessments. In addition, a proper temperature setting is in the interest of the user. Some commercial FFF printers may have a higher actual extruder temperature than displayed and unintended overheating may not only impair the print quality but may cause unnecessarily increased exposure to particle emissions.
Basic oxygen furnace slag (BOFS) is a by-product of steelmaking of which about 10.4 Mt are produced annually in the EU. BOFS is mostly used in road construction, earthwork and hydraulic engineering. However, in this use, the iron bound in BOFS is lost and the opportunity to produce higher value products from BOFS is forgone.
In recent decades, many researchers have investigated the production of both Portland cement clinker and crude iron from BOFS via a thermochemical reductive treatment. The reductive treatment of liquid BOFS causes a reduction of iron oxides to metallic iron, which separates from the mineral phase due to its higher density and can be recovered. An advantage of this process is that simultaneously the chemical composition of the reduced BOFS is adapted to that of Portland cement clinker and the hydraulic reactive mineral alite (Ca3SiO5) is formed.
In this study, German BOFS was reduced in a small-scale electric arc furnace and a low-iron mineral product rich in alite was produced. Despite a chemical and mineralogical composition similar to that of Portland cement clinker, the reduced BOFS produced less heat of hydration, and its reaction was delayed compared to Portland cement. However, adding gypsum accelerated the hydration rate of the reduced BOFS.
Further research to improve the hydraulic properties of the reduced BOFS is essential. If successful, the production of a hydraulic material and crude iron from BOFS could have economic and ecological benefits for both the cement and steel industry.
Kaltwasserzirkulationssysteme haben sich in diversen Bereichen (Kliniken, Hotels, Schiffsbau usw.) etabliert. Die hydraulische Funktionsweise und das Berechnungsverfahren orientieren sich an der bewährten Warmwasser-Zirkulation, dennoch besteht für dieses „neue System“ eine gewisse Einführungsskepsis. Die elementare Anforderung der Trinkwasserverordnung (TrinkwV) besteht darin, dass „Trinkwasser […] so beschaffen sein [muss], dass durch Genuss oder Gebrauch eine Schädigung der menschlichen Gesundheit […] nicht zu besorgen ist.“ Diese Anforderung gilt als erfüllt, wenn mindestens die allgemein anerkannten Regeln der Technik (a.a.R.d.T.) bei Planung, Bau und Betrieb einer Trinkwasser-Installation eingehalten werden, das Trinkwasser den mikrobiologischen, chemischen, radiologischen Anforderungen der TrinkwV entspricht und es rein und genusstauglich ist. Da die Kaltwasserzirkulation aktuell noch dem Stand der Technik zuzuschreiben ist und die Einhaltung chemischer Anforderungen in Bezug auf erhöhte Schwermetallmigration in der Diskussion steht, wurden entsprechende chemische Parameter in Bestandsanlagen untersucht. Die Ergebnisse werden nachfolgend vorgestellt und sollen Betreibern, Fachplanern und ausführenden Fachunternehmen die Vorteile des Systems aufzeigen und Unsicherheiten ausräumen.
The European Commission adopted an EU Energy Label for smartphones and tablets in June 2023. For the first time, the EU Energy Label will depict, among energy efficiency, also a reparability score, battery endurance, battery lifetime, drop resistance and dust and water ingress protection.
However, does the multitude of parameters bear the risk to confuse consumers instead of triggering environmentally sustainable purchase decisions? In a survey in Germany, consumers were asked to make a choice when the label does not clearly identify the environmentally better product. Instead, energy efficiency has to be valued against reparability, reliability against energy efficiency, and reparability against reliability. The sustainability lever of the different aspects is not the same, as e.g. lifetime extension has a much more positive environmental impact than energy efficiency in case of mobile devices. Therefore, the question remains, whether consumers intuitively make the right choice. Results of the survey indicate that consumers interpret the complex label in the desired manner and value those aspects higher, which indeed have a more positive effect on the environment.
Design and construction of a rainfall simulator to test metal runoff at atmospheric conditions
(2023)
A rainfall simulator was presented as an environmental assessment tool to quantify wash-off concentrations from metallic materials. It is part of the RUNOFF-project, which studies and re-assesses the durability of roofing and facade materials under current atmospheric conditions in Germany.
Studying building materials is important as they have a significant impact on achieving a variety of goals and targets within the sustainable developments goals (SDGs). The durability of materials is essential to reach sustainability. However, the durability of metallic materials is strongly depended on climate conditions, which have changed as a result of technical measures in industry, climate change and increasing urbanisation. In Germany at least, the data base is not up-to-date leading to prediction models regarding corrosion resistance and durability of metallic materials which can no longer be trusted and therefore need to be re-assessed and updated. Also, not only the demand for sustainable but also environmentally friendly building materials has increased dramatically. A number of construction materials produce chemical hazards, and therefore have negative impacts on water quality, soils health and ecosystems. To limit these impacts, environmental assessment methods and tools are needed to measure and quantify the inputs and outputs of building materials throughout their lifetime.
Occupational health is an important topic, especially in industry, where workers are exposed to airborne by-products (e.g., dust particles and gases). Therefore, continuous monitoring of the air quality in industrial environments is crucial to meet safety standards. For practical and economic reasons, high-quality, costly measurements are currently only carried out sparsely, both in time and space, i.e., measurement data are collected in single day campaigns at selected locations only.
The project “Robot-assisted Environmental Monitoring for Air Quality Assessment in Industrial Scenarios” (RASEM) addresses this issue by bringing together the benefits of both – low- and high-cost – measuring technologies enabling cost-efficient long-term air quality monitoring in realtime: A stationary network of low-cost sensors that is augmented by mobile units carrying high-quality sensors. By mapping the distribution of gases and particles in industrial environments with the proposed RASEM system, measures can be identified to improve on-site working conditions much faster than using traditional methods.
In this presentation, we detail the technical aspects of RASEM and introduce the mobile platforms used.
Materials that support natural biodiversity on their surfaces can compensate for human activities that have a negative impact on nature and thus contribute to a carbon-neutral and nature-positive world. Specifically designing bioreceptive materials which favor the growth of biofilms on their surface is an approach complementing conventional, macroscopic green façades. But what exactly characterizes a bioreceptive substrate and how do biofilm and substrate interact? How and why does a spontaneous colonization and the formation of biofilms take place? What are biofilms and how can they be established in a laboratory setting? How can this existing knowledge be transferred to the artificial stone concrete so that this material can be tuned to increase (or decrease) its bioreceptivity?
This review paper aims at summarizing the existing state of knowledge on bioreceptive concrete and pointing out inconsistencies and contradictions which can only be removed by more interdisciplinary research in the field.
Current decontamination strategies of PFAS-burdened soils mainly consist of adsorption methods using adsorbents for fixation of PFAS in the ground. A second option is the utilization of a “pump and treat” process, cycling polluted soils through a washing plant leading to the concentration of the pollutants in the fine fraction. Only a subsequent, high-energy consuming pyrolysis process guarantees the total destruction of all fluorinated organic contaminants. These approaches are cost-intensive and not intended for the direct decomposition of all PFAS contaminants. Hence, there is a great demand for innovative developments and chemical treatment technologies, dealing with new strategies of tackling the PFAS problem. Thus, we investigated mechanochemical treatment of PFAS contaminated soils with various additives in a ball mill and analyzed the PFAS defluorination with gas chromatography mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively, as well as the fluoride mineralization by ion chromatography (IC) and fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy.
On the use of Carbograph 5TD as an adsorbent for sampling VVOCs: validation of an analytical method
(2023)
A standardised method for the analysis of very volatile organic compounds (VVOCs) in indoor air is still missing. This study evaluates the use of Carbograph 5TD as an adsorbent for 60 compounds (47 VVOCs + 13 VOCs) by comparing their recoveries with different spiking modes. The influence of the spiking of the tubes in dry nitrogen, humidified air or along the whole flushing duration mimicking real sampling was investigated. 49 substances (36 VVOCs from C1 to C6) had recoveries over 70% on the adsorbent in humidified air and were validated. The linearity of the calibration curves was verified for every spiking mode and the limits of detection (LOD) and quantification (LOQ) were determined. The LOQs were lower than the existing indoor air guideline values. The robustness of the method was considered by studying the influence of the sampling volume, the sampling flow rate, the humidity level and the storage of the tubes. In general, the most volatile or polar substances were the less robust ones. The combined measurement uncertainty was calculated and lies below 35% for a vast majority of the substances. An example of an emission chamber test using polyurethane foam is shown: Carbograph 5TD performs much better than Tenax® TA for VVOCs and emissions from n-butane were quantified with combined measurement uncertainty.
The presentation gives general information about the European Standard EN 16516 “Construction products – Assessment of release of dangerous substances – Determination of emissions into indoor air”. This test standard was developed based on the mandate M/366 of the European commission and is a horizontal reference method for the determination of volatile organic compounds (VOC) from different classes of construction (building) products. Specific test conditions are to be selected by the product TCs (technical committees) in a way that a product is tested under its intended condition of use.
The test is based on the use of emission test chambers which are operated at constant air change rate and climate (23°C, 50 % r.h.) over 28 days. The standard defines the conditions and requirements for the measurement including loading factor, air change rate, sampling, analysis and calculation of emission rates of the substances. A 30 m³ reference room is described which is used to calculate air concentrations from the determined emission rates.
The standard EN 16516 enables the evaluation of construction products regarding their emissions into indoor air under defined and comparable conditions. The evaluation includes the determination of identified target compounds, non-identified target compounds, volatile carcinogenic compounds and the sum values TVOC, TSVOC and R.
Microbiologically influenced corrosion (MIC) is a phenomenon of increasing concern which affects various materials and sectors of society. MIC describes the effects, often negative, that a material can experience due to the presence of microorganisms. Unfortunately, although several research groups and industrial actors worldwide have already addressed MIC, discussions are fragmented, while information sharing and willingness to reach out to other disciplines is limited. A truly interdisciplinary approach, that would be logical for this material/biology/chemistry-related challenge, is rarely taken. In this review we highlight critical non-biological aspects of MIC that can sometimes be overlooked by microbiologists working on MIC but are highly relevant for an overall understanding of this phenomenon. Here, we identify gaps, methods and approaches to help solve MIC related challenges, with an emphasis on the MIC of metals. We also discuss the application of existing tools and approaches for managing MIC and propose ideas to promote an improved understanding of MIC. Furthermore, we highlight areas where the insights and expertise of microbiologists are needed to help progress this field.
Volatile organic compound (VOC) emissions from consumer products contribute to human inhalation exposure and may cause adverse health effects. Existing methods to determine long-term VOC emissions from e.g. building products need to be verified for their suitability to reliably detect initial VOC emissions from consumer products within the first hours and days of use, which would facilitate realistic inhalation exposure assessments. To investigate this issue, VOCs emitted from a test sample were determined in a large-scale emission test chamber and in two micro-chambers of different volumes, and the results were compared.
Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance.
Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance.
Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance.
Sustainability has become the conscientious and future-oriented principle of modern resource management and environmental protection because caring for the future is tantamount to providing manageable and healthy surroundings for ourselves. For the foreseeable future, geotechnical and environmental engineers must therefore be concerned with ensuring a healthy balance between extraction, processing, manufacturing, utilization, recycling, and disposal of materials and products.
VOC-emissions and their odours from building products and furnishings present indoors should not have an impact on personal well-being or health. Odours can be measured by applying the standard ISO 16000-28. Indoor air determination of odour emissions from building products using test chambers. One of the described procedures is the assessment of perceived intensity using a comparative scale by a group of panellists. In this paper, the perceived intensity sampling procedure and its evaluation method are investigated and shown to need improvement. New technical developments in the methodology used to increase the reproducibility of measurement results are discussed. Since odour tests are used for labelling, they have a major influence on the assessment of construction products, similar to the procedure of the German Committee for Health Evaluation of Building Products (AgBB). In the original ISO standard, the evaluation is typically performed using a sampling container separated from the emission chamber. For a better sample presentation, an adapter was developed to connect the emission test chamber to the evaluation funnel and thus enable an odour assessment which is comparable to a direct measurement. The investigations show that losses of odourous substances can be greatly reduced, which is very desirable when seeking to obtain reliable results in odour measurement. Another experimental series was carried out to reduce the measurement effort in the evaluation of perceived intensity. Application of the developed greater than or less than/equal to. query could be helpful here. The results show that the query mostly leads to the same result as the evaluation of the perceived intensity using the method according to the standard but is much easier to perform. Overall, the results can contribute to improving the acceptance of the evaluation of perceived intensity using ISO 16000-28 and to determining odours from building materials increasingly more precisely.
Outer membrane lipopolysaccharides (LPS) play a crucial role in determining attachment behavior and pathogenicity of bacteria. The aim of this study was to develop a simple procedure for anchoring bacterial lipopolysaccharides to polystyrene (PS) microparticles as a model system for in situ attachment studies. By using a swellcapture methodology, commercially available LPS of Pseudomonas aeruginosa (strain ATCC 27316 serotype 10.22) was anchored onto PS microparticles in a proof-of-concept study. A detailed chemical and morphological characterization has proven the success of LPS incorporation. It was shown that the coverage and structure of the LPS film was concentration dependent. The procedure can easily be adapted to LPS of other bacterial strains to generate a synthetic model toolkit for attachment studies.
Growth factors are a class of proteins that play a role in the proliferation (the increase in the number of cells resulting from cell division) and differentiation (when a cell undergoes changes in gene expression becoming a more specific type of cell) of cells. They can have both positive (accelerating the normal healing process) and negative effects (causing cancer) on disease progression and have potential applications in gene therapy and wound healing. However, their short half-life, low stability, and susceptibility to degradation by enzymes at body temperature make them easily degradable in vivo. To improve their effectiveness and stability, growth factors require carriers for delivery that protect them from heat, pH changes, and proteolysis. These carriers should also be able to deliver the growth factors to their intended destination. This review focuses on the current scientific literature concerning the physicochemical properties (such as biocompatibility, high affinity for binding growth factors, improved bioactivity and stability of the growth factors, protection from heat, pH changes or appropriate electric charge for growth factor attachment via electrostatic interactions) of macroions, growth factors, and macroion-growth factor assemblies, as well as their potential uses in medicine (e.g., diabetic wound healing, tissue regeneration, and cancer therapy).
Specific attention is given to three types of growth factors: vascular endothelial growth factors, human fibroblast growth factors, and neurotrophins, as well as selected biocompatible synthetic macroions (obtained through standard polymerization techniques) and polysaccharides (natural macroions composed of repeating monomeric units of monosaccharides). Understanding the mechanisms by which growth factors bind to potential carriers could lead to more effective delivery methods for these proteins, which are of significant interest in the diagnosis and treatment of neurodegenerative and civilization diseases, as well as in the healing of chronic wounds.
BPA is a chemical commonly used in the production of polymer-based materials that can have detrimental effects on the thyroid gland and impact human reproductive health. Various expensive methods, such as liquid and gas chromatography, have been suggested for detecting BPA.
The fluorescence polarization immunoassay (FPIA) is an inexpensive and efficient homogeneous mix-and-read method that allows for high-throughput screening. FPIA offers high specificity and sensitivity and can be carried out in a single phase within a timeframe of 20–30 min. In this study, new tracer molecules were designed that linked the fluorescein fluorophore with and without a spacer to the bisphenol A moiety. To assess the influence of the C6 spacer on the sensitivity of an assay based on the respective antibody, hapten–protein conjugates were synthesized and assessed for performance in an ELISA setup, and this resulted in a highly sensitive assay with a detection limit of 0.05 µg/L. The lowest limit of detection was reached by employing the spacer derivate in the FPIA and was 1.0 µg/L, working range from 2 to 155 µg/L. The validation of the methods was conducted using actual samples compared to LC–MS/MS, which served as the reference method. The FPIA and ELISA both demonstrated satisfactory concordance.
Per- and polyfluoroalkyl substances (PFAS) are widely used for durable water-repellent finishing of different fabrics and textiles like outdoor clothing, carpets, medical textiles and more. Existing PFAS extraction techniques followed by target analysis are often insufficient in detecting widely used side-chain fluorinated polymers (SFPs) that are barely or non-extractable. SFPs are typically copolymers consisting of a non-fluorinated backbone with perfluoroalkyl side-chains to obtain desired properties. We compared the accessible analytical information and performance of complementary techniques based on oxidation (dTOP assay, PhotoTOP), hydrolysis (THP assay), standard extraction, extractable organic fluorine (EOF), and total fluorine (TF) with five functional textiles and characterized 7 further textiles only by PhotoTOP oxidation. The results show that when applied directly to textile samples, oxidation by dTOP and PhotoTOP and also hydrolysis by the THP are able to capture large fractions of the TF in form of perfluoroalkyl side-chains present in the textiles while methods relying on extracts (EOF, target and non-target analysis) were much lower (e.g., factor ~25-50 lower). The conversion of large fractions of the measured TF into PFCAs or FTOHs from fluorinated side chains is in contrast to previous studies. Concentrations ranged from <LOQ to over ~1000 mg F/kg after oxidation/hydrolysis and <LOQ to over 2000 mg F/kg for TF, while EOF and target PFAS in extracts were detected at much lower concentrations (up to ~ 60 mg F/kg) (amount of fluorine in the order: extraction << EOF << oxidation/hydrolysis ≤ TF). Perfluoroalkyl carboxylic acids (PFCAs) and fluorotelomer alcohols (FTOHs) from THP and PhotoTOP both represented the chain-length distribution in the textiles showing that long-chain SFPs are still used in current textiles. Further advantages and disadvantages of the applied methods are discussed.
By tracing sustainability impacts along the supply chain, certification schemes and labels are crucial to unlock the potential of bio-based systems in achieving several SDGs. However, the rapid proliferation of certification schemes and labels led to questioning their effectiveness and robustness and to what extent they deliver important outcomes, in line with sustainability policy priorities. The STAR4BBS project develops indicators and a monitoring system for assessing the effectiveness and robustness of existing certification schemes and labels, applicable to biological feedstock and bio-based materials and products.
Une transition mondiale vers des systèmes énergétiques plus durables, abordables et fiables a été initiée par l’accord de Paris et l’Agenda 2030 des Nations unies pour un développement durable. Il s’agit là d’un défi industriel majeur car les systèmes et infrastructures énergétiques résilients au changement climatique exigent de se positionner pour le long terme. Se pencher sur le comportement dans la durée des matériaux structurels - principalement des métaux et des alliages - s’impose alors comme une nécessité. Dans cette optique, « La corrosion : un défi pour une société durable »présente une série de cas montrant l’importance de la tenue à la corrosion et de la protection anticorrosion des métaux et des alliages pour le développement de systèmes durables, économiques et fiables de production d’énergie.
Understanding the fundamentals of bioreceptivity enables the developement of functionalized materials. Concrete as the most used building material worldwide is of special interest as microbially greened panels may represent an alternative to classic façade greening with plants. This project includes extensive outdoor experiments, in which eight differently structured concrete panels are weathered under different conditions, aiming to grow a stable biofilm of photosynthetic eukaryotic organisms. Documentation and data analysis of this experiment will be demonstrated using an example of one of the surfaces.
Adipokinetic hormone (AKH) is a neuropeptide produced in the insect corpora cardiaca that plays an essential role in mobilising carbohydrates and lipids from the fat body to the haemolymph. AKH acts by binding to a rhodopsin-like G protein-coupled receptor (GPCR), the adipokinetic hormone receptor (AKHR). In this study, we tackle AKH ligand and receptor gene evolution as well as the evolutionary origins of AKH gene paralogues from the order Blattodea (termites and cockroaches). Phylogenetic analyses of AKH precursor sequences point to an ancient AKH gene duplication event in the common ancestor of Blaberoidea, yielding a new group of putative decapeptides. In total, 16 different AKH peptides from 90 species were obtained. Two octapeptides and seven putatively novel decapeptides are predicted for the first time. AKH receptor sequences from 18 species, spanning solitary cockroaches and subsocial wood roaches as well as lower and higher termites, were subsequently acquired using classical molecular methods and in silico approaches employing transcriptomic data. Aligned AKHR open reading frames revealed 7 highly conserved transmembrane regions, a typical arrangement for GPCRs.
Phylogenetic analyses based on AKHR sequences support accepted relationships among termite, subsocial (Cryptocercus spp.) and solitary cockroach lineages to a large extent, while putative post-translational modification sites do not greatly differ between solitary and subsocial roaches and social termites. Our study provides important information not only for AKH and AKHR functional research but also for further analyses interested in their development as potential candidates for biorational pest control agents against invasive termites and cockroaches.
Climate change is becoming one of the greatest challenges facing our society, particularly due to the continued use of fossil fuels. The steadily increasing demand for energy and the continuously growing world population will further intensify these challenges. The development of renewable energies is therefore of central importance. The 2020 EU Energy Roadmap aims to increase the share of renewable energies (gross energy consumption) to 55% by 2050.
Hydrogen (H2) has the highest potential to become the primary renewable energy source. It is envisioned that by 2050 up to 24% of the total energy demand of Europe is to be ensured by H2. However, a decisive disadvantage of the climate friendly alternatives is the massive containment demand, which needs to be highly secure, cost efficient and easily extractable.
Underground geological formations (UGF) represent a seemingly optimal alternative to meet the rapidly increasing storage demand. In this context, many studies are currently underway to determine the feasibility and risks of UGF. However, little or no consideration is being given to microbiology. Therefore, in this Research Topic we will focus on achieving a greater understanding of the impact microorganisms exert on UGF, with a particular emphasis on interdisciplinary studies.
As many subsurface microbial communities can use H2 as an electron donor, production of seemingly undesirable metabolic byproducts, such as hydrogen sulfide, methane, and acids, are also to be expected. However, the rate of the H2 conversion by the microorganisms, how their metabolic activities impact the UGF on a short-term and long-term scale, the extent of damages microorganisms exert on the infrastructure, or potential use of microorganisms to enhance UGF are just a few questions that require urgent research to assess the role of microorganisms in this new anthropogenic use of the subsurface environment. These and many questions can be addressed in this article collection. In particular, understanding microbial community changes and activity rates will help assess operational and environmental risks, develop mitigation strategies and provide new insights on life under extreme conditions (i.e., pressure, salinity).
In this Research Topic, the editorial team particularly welcomes Original Research, Hypothesis and Theory, Method, and Review manuscripts that deal with the latest advances in microbiology in formations that are planned or currently prepared for hydrogen storage, from both fundamental and practical points of view. The ultimate objective is to promote a deeper understanding into the sustainability of UGF and generate interdisciplinary research involving microbiologists, reservoir engineers, geologists, chemists, physicists.
The topics of interest include, but are not limited to:
• Microbial diversity in different underground hydrogen storage sites or formations currently being considered for hydrogen storage
• Mechanism and impact of microbial growth under high H2 pressure
• Potential role of microorganisms in the short-term and long-term storage of hydrogen
• Potential influences of microorganisms on the hydrogen storage infrastructure systems, e.g., microbiologically influenced corrosion, biofilm growth
• Hydrogen-solid-microorganism interactions, including the influence of microbial growth on UGF geological parameters
• Mechanism and modelling of microbial impact on hydrogen storage
UGF relevant for this Research Topic include porous media, salt caverns, deep aquifers, hard rock caverns and depleted oil/gas reservoirs.
Larven und adulte Käfer von Korynetes caeruleus (DE GEER 1775) (Coleoptera: Cleridae) wurden in alten Kirchen gesammelt und im Labor auf Kulturen von Anobium punctatum (DE GEER 1774) (Coleoptera, Ptinidae, früher Anobiidae) aufgezogen. Der Bruterfolg von K. caeruleus war gering, aber es wurden grundlegende Parameter des Entwicklungszyklus dieser Art ermittelt. Bei 21 °C und 75 % relativer Luftfeuchtigkeit und einer viermonatigen Kälteperiode bei 4 °C dauerte die Entwicklung von K. caeruleus vom Ei bis zum erwachsenen Tier 2 Jahre. Das Puppenstadium kann nach eineinhalb Jahren erreicht und abgeschlossen werden.
Die Larven von K. caeruleus ernährten sich von den Larven von A. punctatum. Die Nahrungsaufnahme ist eine Kombination aus Saugen von Hämolymphe und Verzehr von Körperteilen. Die sichelartigen Mandibeln der Larven von K. caeruleus durchdringen die Cuticula der Beutetierlarven, gefolgt von pumpenden und saugenden Körperbewegungen.
Erwachsene Käfer von A. punctatum wurden von K. caeruleus-Larven nicht angegriffen. Das Fressverhalten von erwachsenen K. caeruleus wurde nicht untersucht.
In den Zeiten der Globalisierung und der beschleunigten technologischen Entwicklungen lassen sich in den Industrieländern nur mit einer entsprechenden Innovationsdynamik und -dichte die Herausforderungen im Hinblick auf Wachstum, Beschäftigung und Strukturwandel erfüllen. Grundvoraussetzung hierfür ist eine leistungsfähige Forschung. Um die Forschungsinfrastruktur in der Bundesrepublik zu erhalten und global wettbewerbsfähig zu bleiben, sind verstärkte Investitionen des Staates und der Wirtschaft notwendig. Mit den Investitionen im Rahmen der Hightech-Strategie hat die Bundesregierung einen wichtigen Schritt zur Förderung des wissenschaftlich-technischen Fortschritts in Deutschland getan. Die Investitionen in die Forschungsinfrastruktur des Landes sind nun von den Forschungseinrichtungen und Universitäten effektiv und effizient zu nutzen.
Für einen möglichst wirksamen Einsatz der Forschungsetats sind Forschungsprogramme sowohl für die Forschungseinrichtung als auch für die Mittelgeber ein wichtiges Instrument im Hinblick auf die Darstellung der Aktivitäten. Dies gilt insbesondere für die Ressortforschungseinrichtungen des Bundes, zu denen die Bundesanstalt für Materialforschung und -prüfung (BAM) zählt. Diese Einrichtungen verfügen über einen klaren Auftrag und ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Forschungsprogramme dienen daher besonders in diesen Einrichtungen dazu, Perspektiven im Bereich ihres Aufgabenfeldes sowie ihre Forschungsaktivitäten transparent darzustellen und politisch vertretbar zu machen.
Das vorliegende Forschungsprogramm der BAM gibt einen Überblick über die in den nächsten Jahren aktuellen Forschungsthemen und die hierfür erforderlichen Ressourcen und Rahmenbedingungen.
Disinfectants are important to prevent the transmission of pathogens, especially in the face of the current antibiotic resistance crisis. The crisis is further exacerbated by phenotypically tolerant persister subpopulations that can survive transient antibiotic treatment and facilitate resistance evolution. Despite the transient nature of disinfectant application, persistence to disinfectants and its role for the evolution of tolerance and cross-resistance to antibiotics has not been studied. Our work shows that E. coli displays persistence against several widely used disinfectants, including benzalkonium chloride (BAC), didecyldimethylammoniumchlorid (DDAC) and isopropanol. The molecular mechanism of BAC persistence is triggered in stationary phase and affected by several antibiotic persister genes (hipA, tisB, tolC, relA, spoT). Experimental evolution and population dynamic modeling show that repeated failure of disinfection due to persisters rapidly selects for BAC tolerance underpinned by reduced cell surface charge due to mutations in genes related to lipid A acylation (lpxML). Furthermore, evolved BAC tolerance affects the susceptibility to antibiotics, leading to positive selection of disinfectant tolerant strains at environmentally relevant antibiotic concentrations and variations in evolvability of antibiotic resistance due to epistatic effects. These results highlight the need for faithful application of disinfectants to steward their efficacy and the efficacy of antibiotics. A better understanding of the bacterial response to disinfectants is crucial to understand and avert the ongoing antimicrobial resistance crisis.
Excessive discharge of quaternary ammoniumdisinfectants such as benzalkonium chloride (BAC) into aquatic systems can trigger several physiological responses in environmental microorganisms. In this study, we isolated a less-susceptible strain of Aeromonas hydrophila to BAC, designated as INISA09, froma wastewater treatment plant in Costa Rica. We characterized its phenotypic response upon exposure to three dierent concentrations of BAC and characterizedmechanisms related to its resistance using genomic and proteomic approaches. The genome of the strain, mapped against 52 dierent sequenced A. hydrophila strains, consists of approximately 4.6Mb with 4,273 genes. We found a massive genome rearrangement and thousands of missense mutations compared to the reference strain A. hydrophila ATCC 7966.
We identified 15,762 missense mutations mainly associated with transport, antimicrobial resistance, and outer membrane proteins.
In addition, a quantitative proteomic analysis revealed a significant upregulation of several efflux pumps and the downregulation of porins when the strain was exposed to three BAC concentrations.Other genes related tomembrane fatty acid metabolism and redox metabolic reactions also showed an altered expression.
Our findings indicate that the response of A. hydrophila INISA09 to BAC primarily occurs at the envelop level, which is the primary target of BAC. Our study elucidates the mechanisms of antimicrobial susceptibility in aquatic environments against a widely used disinfectant and will help better understand howbacteria can adapt to biocide pollution. To our knowledge, this is the first study addressing the resistance to BAC in an environmental A. hydrophila isolate. We propose that this bacterial species could also serve as a new model to study antimicrobial pollution in aquatic environments.
Silver nanoparticles (AgNPs) nowadays appear in close to 24% of consumer products that contain engineered nanomaterials. Thus, they are expected to be released into the environment, where their fate and effect are still undetermined. Considering the evidenced efficacy of the single particle Inductively Coupled Plasma – Mass Spectrometry (sp ICP-MS) technique in the study of nanomaterials, this work reports on the use of sp ICP-MS along with an online dilution sample introduction system for the direct analysis of untreated and spiked seawater samples, as part of a larger scale experiment studying the fate of Ag (ionic and nanoparticles) in seawater mesocosm systems. Silver nanoparticles coated with branched polyethyleneimine (BPEI@AgNPs) or ionic silver (Ag+) were introduced gradually into the seawater mesocosm tanks at very low, environmentally relevant concentrations (50 ng Ag L− 1 per day, for 10 consecutive days, up to a total of 500 ng Ag L− 1 ), and samples were collected and analyzed daily, within a consistent time window. Using very low detector dwell time (75 μs) and specialized data treatment, information was obtained on the nanoparticles’ size distribution and particle number concentration, as well as the ionic silver content, of both the AgNPs and the Ag+ treated seawater mesocosm tanks. The results for the AgNP treated samples indicated the rapid degradation of the added silver particles, and the subsequent increase of ionic silver, with recoveries close to 100% for the first days of the experiment. On the other hand, particle formation was observed in the Ag+ treated seawater tanks, and even though the number concentration of silver-containing nanoparticles increased throughout the experiment, the amount of silver per particle remained relatively constant from the early days of the experiment. In addition, the online dilution sample introduction system for the ICP-MS proved capable of handling the untreated seawater matrix without significant contamination issues and downtime, while the low dwell time and data treatment procedure developed were shown to be suitable for the analysis of nanomaterials at the low nm-scale, despite the complex and heavy matrix introduced into the ICP-MS.
Im Verbundprojekt RUSEKU wurde die Probenahme von Wasserproben entscheidend weiterentwickelt. Wichtig ist hierbei zu gewährleisten, dass genügend Merkmalsträger in jeder Probe untersucht werden. Es muss daher eine für den Probenahmeort repräsentative Beprobung hinsichtlich des Wasservolumens in Abhängigkeit der Partikelanzahl gewährleistet sein.
Das Hauptaugenmerk lag im vorliegenden Projekt auf einer praxisnahen Beprobungsstrategie. Es wurden verschiedene Konzepte ausprobiert.
• Grundsätzlich hat sich gezeigt, dass eine Stichprobe eine Momentaufnahme des MP-Massengehaltes zeigt. Es wird eine hohe Statistik, also eine Vielzahl an Messungen am gleichen Probenahmeort, benötigt, um eine valide Aussage über den MP-Gehalt zu machen.
• Es zeigt sich, dass eine integrale Probenahme über mehrere Wochen mit dem SK routinemäßig möglich ist. Die erfassten MP-Massen sind reproduzierbar und robust.
• Die DFZ ist für Stichproben geeignet. Partikel < 50 µm werden eventuell unterschätzt
• Die fraktionierte Filtration kann für Stich- und Mischproben direkt im Feld genutzt werden. Fraktionen von 10 und 5 µm werden später im Labor Vakuum filtriert. Es erfolgt eine Fraktionierung der Probe mit Siebmaschenweiten von 1000, 500, 100, 50, 10 und 5 µm.
• Die fraktionierte Filtration kann auch anschließend an die Beprobung mit dem SK zur Anwendung kommen. Wird die mit dem SK gewonnene Wasserprobe fraktioniert filtriert, kann neben einem MP-Gesamtgehalt auch eine Einschätzung über die Partikelgrößen gewonnen werden.
• Für Wässer mit geringen Partikelzahlen wurde ein Messfiltertiegel entwickelt. Dieser hat eine Maschenweite von 6 µm. Seine Anwendung kann mögliche Verluste beim Transferieren vom Probenahmetool zum Messgefäß und mögliche Kontaminationen reduzieren.
Die Optimierung der Probenahmestrategie wurde durch Modellversuche und Simulationen unterstützt. Modellversuche zum Sinkverhalten und Simulationen von MP in realen Gewässern verdeutlichten das komplexe Verhalten der Partikel. Es konnte gezeigt werden, dass Partikel ab einer bestimmten Größe (und kleiner) bei genügend starker Turbulenz sich in der Wassersäule unabhängig von ihrer Dichte verhalten und so auch MP mit kleiner Dichte (z.B. PE) in der gesamten Wassersäule zu finden sind. Es konnte mit dem TEM die Existenz von NP gezeigt werden.
Ein wesentlicher Aspekt des RUSEKU Projektes war die Beprobung realer Kompartimente. Beprobt wurde neben Oberflächengewässern, das urbane Abwassersystem der Stadt Kaiserslautern, Waschmaschinenabwasser und Flaschenwasser.
• In Oberflächengewässern wurde hauptsächlich PE gefunden. Je nach Probe und Gewässer konnten auch PP, PS, PET, PA, SBR und Acrylate nachgewiesen werden.
• Im urbanen Abwassersystem der Stadt Kaiserslautern konnte an allen Probenahmestandorten MP nachgewiesen werden. Es wurde hauptsächlich PE, neben geringeren Mengen an PP, PS und SBR gefunden. Nach einem Regenereignis war der SBR Anteil deutlich erhöht.
• Die Beprobung eines realen Wäschepostens, bestehend aus T-Shirts und Hemden mit PA/CO oder PES/CO Mischgewebe, zeigte einen PA- und PES-Austrag im Waschwasser. Der überwiegende Teil der detektierten Fasern ist aber auf Baumwolle zurückzuführen. Reine gravimetrische Messungen zur Detektion von MP führen zu einer starken Überschätzung.
• In Flaschenwasser (PET-Flaschen) konnte MP detektiert werden. PET wurde nur im stillen Mineralwasser, nicht in Mineralwasser mit Kohlensäure gefunden werden. Teilweise wurde auch das MP-Material des Verschlusses im Wasser detektiert.
• Für Luftproben konnte ein Aufbau zur größenselektiven Beprobung getestet werden.
Neben der Probenahme hat das Projekt auch gezeigt, dass die TED-GC/MS geeignet für die MP-Detektion im Routinebetrieb ist. Die TED-GC/MS konnte weiter optimiert werden. Es wurden MP-Massen bestimmt.
Im Projekt wurden erste realitätsnahe Referenzmaterialien für die MP Detektion hergestellt. Die Herstellung von realitätsnahen Polymeren in ausreichender Homogenität und Menge hat sich als große Herausforderung herausgestellt.
Der Vortrag stellt das Forschungsvorhaben RUNOFF vor, welcher auf der zweitägigen Veranstaltung „24. Projekttage der Bauforschung“ gehalten wurde. Die Präsentation erläutert zunächst die Bedeutung der Abschwemmung von Metallionen für die Bauindustrie und Umwelt. Dabei werden Faktoren, welche den Schadstofftransport im urbanen Raum begünstigen sowie Stadtentwässerungstypen vorgestellt. Anschließend folgen Folien zum wissenschaftlichen Hintergrund zur Ausbildung von Deckschichten, aktuellen Wissensstand sowie Lücken in der Korrosionsforschung von metallenen Werkstoffen unter atmosphärischen Bedingungen. Nach einer kurzen Übersicht zu den Hauptzielen des Forschungsvorhabens wurde detaillierter auf die Versuchsdurchführung sowie fünf der acht Arbeitspakete mitsamt Zwischenergebnissen eingegangen.
Bisphenol A (BPA) is used in Polycarbonate (PC), polyacrylic resins (PAR), polysulfones (PSU), epoxy resins (ER), and polyetherimides (PEI). It is also applied in recycled polyvinyl chloride (PVC). Many outdoor applications are made from these BPA-based materials which are exposed to a variety of environmental impacts, like temperature, global radiation, rain, and others. This could lead to damaging and aging of the material which might cause leaching or migration of pollutants into the environment.
Understanding the fate and behavior of the released pollutants is very important. Therefore, different transformation products (TP) will be generated and analyzed:
1. To investigate the behavior of various bisphenols in wastewater treatment plants, possible technical TP are generated by UV irradiation. Simulation of Industrial wastewater treatment is realized by using the Fenton reaction, an advanced oxidation process.
2. To study the transformation of bisphenols in surface waters, global radiation will be simulated by using UVA lamps.
3. To simulate phase 1 metabolism, an electrochemical cell coupled to a mass selective detector is applied.
The analysis of metabolites and TP are achieved by a variety of gas and liquid chromatographic techniques coupled with mass spectrometry. The elucidation of the exact structure of the obtained TP and metabolites are done by 1H- and/or 13C-NMR experiments.
Per- and polyfluoroalkyl substances (PFAS) are a large and ever-growing class of chemicals that are widely used. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonic acid (PFOS) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment.
In recent years, many ‘hot spot’ sites with high PFAS contaminations in the soils have been distinguished,but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions.
600 soil samples are freshly taken at different sites all over Germany. PFAS are extracted from all samples. The extracts are analysed using LC-MS/MS with 30 PFAS as target compounds. Eluates are produced and analysed using targeted LC-MS/MS. To determine the amount of precursor substances not included in the targeted list, total oxidisable precursor (TOP) assays are performed with different approaches. Additionally, 50 samples taken at the same locations in 2012 are analysed to determine temporal trends of PFAS contamination. The determination of total extractable organically bound fluorine (EOF) is planned for comparison.
The aim of the project is to obtain a broad overview of the status and development of the PFAS contamination in soil in Germany. By the preparation and analysis of eluates, the leaching behaviour of the analytes and thereby their mobility in the environment is investigated, helping to understand the transport of PFAS from contaminated soil to water. The use of different TOP assay methods allows to compare their results and usability in routine analysis, thereby giving insights into the amount of PFAS contamination hidden to targeted analysis and helping inspire future analysis strategies. The future comparison of these results to EOF analysis may further underline this point. The large number of samples and the geographic distribution of the sampling is unprecedented in Germany and allows to determine high-risk sites and ‘hot spots’. In the future, the insights from the project may be used as a guide for the political regulation of uses of PFAS.
Die voranschreitende Digitalisierung, die Globalisierung sowie die daraus resultierende beschleunigte technologische Entwicklung bringen heute für die Industrieländer Herausforderungen im Hinblick auf Wachstum, Beschäftigung und Strukturwandel mit sich, denen nur mit einer entsprechenden Innovationsdynamik und -dichte begegnet werden kann. Grundvoraussetzung hierfür ist eine leistungsfähige Forschung und Entwicklung ebenso wie Wissens- und Technologietransfer zur Umsetzung von Forschungsergebnissen in marktfähige Produkte und Dienstleistungen. Europa hat sich im Rahmen des Lissabon-Prozesses zum Ziel gesetzt, den Anteil der Forschungsausgaben am Bruttoinlandsprodukt auf 3 % zu steigern. Um die Forschungsinfrastruktur in der Bundesrepublik zu stärken und global wettbewerbsfähig zu bleiben, hat die Bundesregierung mit der Hightech-Strategie 2025 einen weiteren wichtigen Schritt zur Förderung des wissenschaftlich-technischen Fortschritts in Deutschland getan.
Forschungsprogramme sind sowohl für Forschungseinrichtungen als auch für Mittelgeber ein wichtiges Instrument für die Darstellung und Steuerung ihrer Aktivitäten. Dies gilt auch für die Bundeseinrichtungen mit Forschungs- und Entwicklungsaufgaben, zu denen die Bundesanstalt für Materialforschung und -prüfung (BAM) zählt. Die BAM verfügt über einen klaren gesetzlichen Auftrag für die Sicherheit in Technik und Chemie. Ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Das Forschungsprogramm zeigt Perspektiven im Bereich ihres Aufgabenfeldes sowie ihrer damit verbundenen Forschungsaktivitäten transparent und politisch nutzbar auf und dient darüber hinaus der Koordinierung der Ressortforschung. Das Forschungsprogramm der BAM wird alle zwei Jahre aktualisiert. Es gibt einen Überblick über die aktuellen und zukünftigen Forschungsthemen und die hierfür erforderlichen Rahmenbedingungen.
Die von der Europäischen Kommission im Jahr 2021 empfohlene, systematische Abwasserüberwachung mittels PCR-Techniken wird als ein wirksames Früh-warnsystem für künftige Pandemien durch Viren und andere Krankheitserreger betrachtet. Ein generelles Problem bei jeder quantitativen Messung von Parametern im Abwasser ist die starke Schwankung des Abwasservolumens und seiner Zusammensetzung im Tages- und Jahreszeitenverlauf. Um die Konzentrationsbestimmungen von Krankheitserregern im Abwasser in Korrelation mit menschlichen Einträgen setzen zu können, könnten sog. "anthropogene Marker" eine herausragende Rolle spielen, deren Eintrag ins Abwasser menschlichen Ursprungs sind. Im Projekt werden mittels ELISA die Konzentrationen ausgewählter anthropogener Marker in deutschlandweit gesammelten Abwasserproben erhoben und analysiert.
Die Europäische Kommission präsentierte am 11. Dezember 2019 den European Green Deal, ein Konzept mit dem Ziel, bis zum Jahr 2050 als erster Kontinent Klimaneutralität zu erreichen. Mit Inkrafttreten der Verordnung (EU) 2021/1119 des Europäischen Parlaments und des Europäischen Rates am 29. Juli 2021 zur Schaffung des Rahmens für die Verwirklichung der Klimaneutralität („Europäisches Klimagesetz“), ist dieses, sowie das Ziel der Reduzierung der Nettotreibhausgasemissionen um mindestens 55 % bis 2030 in der Gesetzgebung der Europäischen Union verankert. Die Stahlindustrie in der Europäischen Union mit ca. 57 Mio. t Nettotreibhausgasemissionen im Jahr 2020, die annähernd 2 % der Emissionen der Europäischen Union ausmachen (Inklusive Energie: 127 Mio. t; 4 %), bekennt sich zur erheblichen Reduzierung der CO2-Emissionen bis zum Jahr 2030 und zum Erreichen der Klimaneutralität bis zum Jahr 2050. Als Schlüsselwege zur Verwirklichung dieser Zielstellung hat sie zum einen Smart Carbon Usage (SCU) und zum anderen Carbon Direct Avoidance (CDA) in einer Roadmap formuliert. SCU umfasst CO2-reduzierende Maßnahmen in bestehenden Eisen- und Stahlproduktionsprozessen, Carbon Capture and Storage- (CCS) sowie Carbon Capture and Usage-Technologien (CCU). Wohingegen bei CDA CO2-Emissionen durch erneuerbare elektrische Energie sowie wasserstoffbasierte Reduktion des Eisenerzes gar nicht erst entstehen sollen. Der CDA-Weg, der voraussichtlich beschritten werden muss, um eine klimaneutrale Stahlproduktion zu erreichen [38], geht mit einer kostenintensiven Transformation der Stahlproduktion einher, die bereits von vielen Unternehmen der Stahlindustrie eingeleitet wurde und von der im Wesentlichen die beiden in Europa vorherrschenden Stahlproduktionsrouten Hochofen-Konverter-Route und Elektrolichtbogenofen-Route betroffen sind. Die CO2-Emissionen der Hochofen-Konverter-Route, von denen der überwiegende Anteil auf den Hochofen fällt, liegen laut einer für das Jahr 2015 erstellten Studie bei 1921 kg CO2/t Rohstahl inklusive der CO2-Last der Pellets als Einsatzmaterial sowie der Emissionen der nachgelagerten Stranggießanlagen und Walzwerke. Im Hochofen wird das Eisenerz durch Kohlenstoff (C) bzw. Kohlenstoffmonoxid (CO) – welche größtenteils aus dem Koks, der dem Hochofen zusammen mit dem Möller über die Gicht zugeführten wird, stammen – unter Entstehung von Roheisen und Kohlenstoffdioxid (CO2) reduziert. Das neben dem CO2 im Prozessgas enthaltene CO wird zum Beispiel zur Energiegewinnung in peripheren Prozessen ebenfalls unter Bildung von CO2 verbrannt. Zusätzlich zur Reduktion hat der Koks unter anderem physikalische Aufgaben, wie die Errichtung eines Stützgerüstes und die Gewährleistung der Permeabilität im Hochofenprozess. Somit ist eine vollkommene Substitution des Kokses zur Vermeidung der CO2-Emissionen im Hochofen nicht denkbar. Viele Strategien der Stahlunternehmen zum Erreichen der Klimaziele verfolgen daher den Wechsel von der Rohstahlproduktion aus der Hochofen-Konverter-Route hin zur Rohstahlproduktion im Elektrolichtbogenofen (EAF – Electric Arc Furnace) mit dem Einsatz von direkt reduziertem Eisen (Eisenschwamm, DRI – Direct Reduced Iron) aus vorgelagerten Direktreduktionsanlagen, die mit Wasserstoff (H2) als Reduktionsmittel betrieben werden können. Dabei ist die Elektrostahlerzeugung kein neuer Prozess und nimmt in der europäischen Union bereits jetzt einen Anteil von ca. 44 % der Rohstahlproduktion ein, jedoch überwiegend mit Schrott als Einsatzmaterial. Bei der Elektrostahlerzeugung mit Schrotteinsatz fallen laut der oben genannten Studie von Lüngen für das Jahr 20152 410 kg CO2-Emissionen pro Tonne Rohstahl an, von denen der Großteil auf die CO2-Last der fremd bezogenen elektrischen Energie zurückzuführen ist und daher nicht im Produktionsprozess selbst entsteht. Auch die Direktreduktion wird schon seit 1972 in der weltweit zweiten und bis heute in Westeuropa einzigen Direktreduktionsanlage in Hamburg betrieben. Während hier noch mit einem Reduktionsgas gearbeitet wird, das hauptsächlich aus einem aus Erdgas gewonnenen Wasserstoff-Kohlenstoffmonoxid-Gemisch besteht, liegt eine aktuelle Kernherausforderung in der Bereitstellung des in der Größenordnung der von der Transformation betroffenen Rohstahlproduktionskapazitäten notwendigen, mit erneuerbarer elektrischer Energie hergestellten Wasserstoffs. Wird zusätzlich der Strom für das Einschmelzen im Elektrolichtbogenofen aus erneuerbaren Quellen gewonnen und werden schließlich als Brennstoff verwendete Kohle und als Brennstoff verwendetes Erdgas durch CO2-neutrale Bio-Brennstoffe ersetzt, sind sowohl für den Einsatz von mit Wasserstoff reduziertem und auf Pellets ohne CO2-Last basiertem Eisenschwamm als auch für den Einsatz von Schrott CO2-Emissionen von jeweils nur 60 kg CO2/t Rohstahl erreichbar, was eine Reduktion der Emissionen, ausgehend von der Konverter-Hochofen-Route um 97 % und ausgehend von der Schrott-Elektrolichtbogenofen-Route um 85 % bedeuten würde.
Der Betrieb von Elektrolichtbogenöfen macht die an den Standorten vorhandenen Konverter sowie die Infrastruktur für Behandlung und Transport des Roheisens überflüssig. Die fortwährende Nutzung dieser bestehenden Anlagenstruktur dient daher unter anderem als Motivation für die Entwicklung einer zweiten Transformationsstrategie, die einen sogenannten Einschmelzer (SAF – Submerged Arc Furnace) als der Direktreduktionsanlage nachgelagerten Prozess vorsieht, in dem wiederum Roheisen erschmolzen wird, das anschließend im Konverter zu Rohstahl veredelt wird.
Die Transformation der Stahlindustrie beeinflusst einen weiteren CO2-intensiven Industriesektor, nämlich die Zementindustrie die verantwortlich ist für rund 4 % der CO2-Emissionen in der EU. Etwa zwei Drittel dieser Emissionen entfallen als Prozessemissionen auf die Entsäuerung des Rohstoffs Kalkstein (CaCO3), also auf die Abspaltung von CO2 unter Entstehung des für die Herstellung von Zementklinker notwendigen Branntkalks (CaO) als Zwischenstufe bei der Bildung der hydraulischen Phasen Tri- und Dicalciumsilikat. Als eines der fünf Themenfelder (5C-Ansatz: Clinker, Cement, Concrete, Construction, Carbonation), welche die europäische Zementindustrie entlang ihrer Wertschöpfungskette zum Erreichen der gesetzlichen Vorgaben der europäischen Union erarbeitet hat, umfasst das Feld "Cement" zum größten Teil die Reduzierung des Klinker-Zement-Faktors. Im Jahr 2017 betrug er 77 %, das heißt, dass 23 % des Klinkers durch alternative Materialien ersetzt wurden. Bis zum Jahr 2030 wird ein Faktor von 74 % und bis zum Jahr 2050 von 65 % angestrebt. Den größten Anteil an den Klinkersubstituten hat mit 33 % der Hüttensand aus der Stahlindustrie. Bei der Roheisenproduktion im Hochofen entsteht als Nebenprodukt Hochofenschlacke, die unter Zugabe von Schlackebildnern die Gangart des Möllers und mineralische Koksbestandteile abbindet, sowie weitere unerwünschte Begleitelemente wie Schwefel und Alkalien aufnimmt. Allein in Deutschland wurden im Jahr 2021 6,90 Mio. t – das entspricht 90 % der gesamten produzierten Hochofenschlacke – zu glasig erstarrtem Hüttensand granuliert. Dieser Hüttensand besitzt latent hydraulische Eigenschaften und wird daher seit mehr als 140 Jahren als Zementbestandteil eingesetzt, wodurch in Deutschland jährlich rund 4,5 Mio. t CO2-Emissionen eingespart werden. Alle Transformationsstrategien der Stahlindustrie beinhalten die notwendige Außerbetriebnahme der CO2-intensiven Hochöfen. Dies hat unter anderem zur Folge, dass die Hochofenschlacke als Nebenprodukt der Rohstahlerzeugung im Hochofen nicht mehr zur Verfügung stehen wird, wodurch die weitere Reduzierung des Klinker-Zement-Faktors erhebliche Zusatzmengen alternativer Materialien benötigen wird. Derzeit ist noch unklar, ob z.B. calcinierte Tone im benötigten Umfang erzeugt werden können.
Der Fachbereich Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung der Bundesanstalt für Materialforschung und -prüfung (BAM) und das Institut für Baustoffforschung FEhS forschen zusammen mit Industriepartnern und weiteren Forschungseinrichtungen im Rahmen zweier Projekte in den Kooperationssphären der Stahl- und Zementindustrie, die zur Bewältigung dieser Herausforderungen beitragen. Im Projekt SlagCEM wird die Produktion eines hydraulischen Zementbestandteils durch Reduktion von Konverter- bzw. Linz-Donawitz-Schlacke (LDS) untersucht. Die mit den zusätzlich aufgenommen Lichtbogenofenkapazitäten steigenden Mengen an Elektrolichtbogenofenschlacke (EOS, engl. electric arc furnace slag, EAFS) werden im Projekt DRI-EOS behandelt, welches die Produktion eines latent hydraulischen Hüttensandsubstituts zum Ziel hat.