4 Material und Umwelt
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In this article, we present two Coptic papyri, P 11934 and P 11935 from the Berlin collection excavated in Ashmunein (ancient Hermopolis) by Otto Rubensohn in 1906. We employ a multi-disciplinary approach that takes into account both their materiality – writing support as well as ink – and their content, as has become ‘best practice’. 1 Material aspects of written documents have traditionally been the purview of papyrologists. Recently developed methods of scientific analysis generate sets of archaeometric data with the potential to improve understanding of the materiality of ancient document production, as well as to yield new evidence for genuine papyrological research questions. To achieve this, a large corpus of comparative data needs to be built. Our contribution offers a first step in this direction. We aim at presenting the papyri, which were selected because of the ink corrosion during conservation work at the Berlin collection, in a format that is exhaustive both for material and textual aspects. The inks from both papyri were analysed using a combination of techniques, contributing to our better understanding of the development of ink technology in Late Antiquity.
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.
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.
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.
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.
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.
Hydrogen plasma treatment of iron ores or iron oxide containing wastes can be an efficient option to produce green iron e.g. for steel production. This way iron oxide is reduced to metallic iron in the liquid form by the highly reactive species that are formed in a hydrogen plasma. Hydrogen plasma can be used at the same time to remove undesired gangue elements. The presentation shows the experimental setup, shows first results of iron ore reduction by hydrogen plasma and gives an outlook for industrial application of the technology.
Half of global material consumption involves mineral material. The circularity is still low so that the enhanced use of secondary building material is required to close loops. Three different secondary building materials are discussed based on exemplary research results: construction and demolition waste (C&D waste), soil-like material, and incineration bottom ash (IBA). Focus was placed on the environmental compatibility of the materials examined mainly by standardized leaching tests. C&D waste was investigated after a wet treatment using a jigging machine, and soil-like material and IBA were characterized with respect to their material composition. Their environmental compatibilities in particular were studied using standard leaching tests (batch tests and column tests).
It was concluded that soil-like material can mostly be utilized even when the precautionary limit values set are exceeded by a factor of less than two. For C&D waste, the fine fraction below 2 mm and the content of brick material is problematic. IBA fulfills quality level “HMVA-2” following German regulations. Improved levels of utilization might be achievable with better treatment technologies.
Wie können industriell synthetisierte Schadstoffe aus einer Stoffklasse quantifiziert werden, deren genauer Umfang unbekannt ist und auf mehrere tausend Verbindungen geschätzt wird? Im Falle der per- und polyfluorierten alkylierten Substanzen (PFAS) stellen sich Wissenschaftler*innen weltweit seit über zehn Jahren diese Frage. Neben der etablierten Methodik der Einzelstoffanalytik (engl. target analytic) existieren Summenparameteranalysen zur Quantifizierung
organisch gebundener fluorierter Verbindungen in Umweltmedien und Konsumprodukten. An der Bundesanstalt für Materialforschung und -prüfung (BAM) beschäftigen wir uns mit der Weiterentwicklung von Summenparametermethoden am Beispiel von PFAS-belasteten Umweltkompartimenten wie Böden, Klärschlämmen und Gewässerproben sowie PFAS-haltigen Konsumgütern. In diesem Beitrag stellen wir zwei ausgewählte Fallbeispiele vor und diskutieren die Vor- und Nachteile der Methoden im Vergleich zur Einzelstoffanalytik.
For the first time, µ-X-ray fluorescence (µ-XRF) mapping combined with fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy was applied to depict per- and polyfluoroalkyl substances (PFAS) contamination and inorganic fluoride in samples concentrations down to 100 µg/kg fluoride. To demonstrate the matrix tolerance of the method, several PFAS contaminated soil and sludge samples as well as selected consumer product samples (textiles, food contact paper and permanent baking sheet) were investigated. µ-XRF mapping allows for a unique element-specific visualisation at the sample surface and enables localisation of fluorine containing compounds to a depth of 1 µm. Manually selected fluorine rich spots were subsequently analysed via fluorine K-edge µ-XANES spectroscopy. To support spectral interpretation with respect to inorganic and organic chemical distribution and compound class determination, linear combination (LC) fitting was applied to all recorded µ-XANES spectra. Complementarily, solvent extracts of all samples were target-analysed via LC-MS/MS spectrometry. The detected PFAS sum values range from 20 to 1136 µg/kg dry weight (dw). All environmentally exposed samples revealed higher concentration of PFAS with a chain length >C8 (e.g. 580 µg/kg dw PFOS for Soil1), whereas the consumer product samples showed a more uniform distribution with regard to chain lengths from C4 to C8. Independent from quantified PFAS amounts via target analysis, µ-XRF mapping combined with µ-XANES spectroscopy was successfully applied to detect both point-specific concentration maxima and evenly distributed surface coatings of fluorinated organic contaminants in the corresponding samples.
We present how mesoporosity can be engineered in transition metal phosphate (TMPs) materials in a template-free manner. The method involves the transformation of a precursor metal phosphate phase, called M-struvite (NH4MPO4·6H2O, M = Mg2+, Ni2+, Co2+, NixCo1−x2+). It relies on the thermal decomposition of crystalline M-struvite precursors to an amorphous and simultaneously mesoporous phase, which forms during degassing of NH3 and H2O. The temporal evolution of mesoporous frameworks and the response of the metal coordination environment were followed by in situ and ex situ scattering and diffraction, as well as X-ray spectroscopy. Despite sharing the same precursor struvite structure, different amorphous and mesoporous structures were obtained depending on the involved transition metal. We highlight the systematic differences in absolute surface area, pore shape, pore size, and phase transitions depending on the metal cation present in the analogous M-struvites. The amorphous structures of thermally decomposed Mg-, Ni- and NixCo1−x-struvites exhibit high surface areas and pore volumes (240 m2 g−1 and 0.32 cm−3 g−1 for Mg and 90 m2 g−1 and 0.13 cm−3 g−1 for Ni). We propose that the low-cost, environmentally friendly M-struvites could be obtained as recycling products from industrial and agricultural wastewaters. These waste products could be then upcycled into mesoporous TMPs through a simple thermal treatment for further application, for instance in (electro)catalysis.
Vortrag über die Regelungen der AbfKlärV bezüglich P-Rückgewinnung. Diskussion der Auswirkung einer konzentrationsbezogenen Grenze auf die Pflicht zur P-Rückgewinnung. Diskussion der nach AbfKlärV zulässigen analytischen Verfahren zur Bestimmung von P in Klärschlamm und Ableitung von Empfehlungen. Vorstellung der Ergebnisse eines Ringversuchs mit 28 Laboren.
Besides classical per- and polyfluorinated alkylated substances (PFAS), side-chain fluorinated polymers (SFPs) are widely applied as efficient anti-wetting and anti-greasing coatings in various daily applicated consumer products such as outdoor apparel, carpetry or paper-based food contact materials. Although the fluorinated sidechains are chemically bound to a base polymer, their release can be triggered by environmental influences or wear-off, thus contribute as significant sources of PFAS in the environment. Since only little knowledge of PFAS and SFP composition in consumer products is available, a comprehensive analytical approach might be beneficial.
Per- and polyfluoroalkyl substances (PFAS) are a group of anionic, cationic and zwitterionic synthetic products, in which the hydrogen atoms on the carbon skeleton of at least one carbon atom have been completely replaced by fluorine atoms and which include more than 4730 compounds, depending on the definition. As a result of continuous and prolific use, mainly in aviation firefighting foams, thousands of industrial and military installations have been found to contain contaminated soil, groundwater and surface water. Furthermore, current decontamination strategies of PFAS-burdened soils mainly consist of adsorption methods using adsorbents for fixation of PFAS in the ground. 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. In this presentation the advantages of fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy for various environment samples are shown.
In Deutschland fallen aktuell pro Jahr über 5 Mio. Tonnen Hausmüllverbrennungs-aschen (HMVA) an. Eine Verwertung dieser Aschen und Schlacken ist in Deutschland möglich und findet überwiegend im Deponiebau statt. Für die Verwertung sind in der Ersatzbaustoffverordnung Eluatgrenzwerte für Schwermetalle und einige andere Parameter vorgesehen.
Der Umgang mit HMVA könnte durch eine Einstufung als gefährlicher Abfall erschwert werden. Maßgeblich für die Einstufung eines Abfalls als gefährlich oder ungefährlich sind die gefahrenrelevanten Eigenschaften HP 1 bis HP 15 nach Anhang III der Richtlinie 2008/98/EG über Abfälle mit dort festgelegten Konzentrationsgrenzen. Für HMVA ist im Wesentlichen nur der Parameter HP 14 (Ökotoxizität) von Bedeutung. Dafür sind entscheidend die Gehalte an chemischen Verbindungen mit den Gefahrenhinweiscodes (hazard statement code, HSC) H400, H410, H411, H412 und H413. Eine detaillierte Diskussion zu den übrigen Gefahreneigenschaften bei HMVA findet sich in der Literatur. Die Einstufung als gefährlicher Abfall erfolgt nach festgelegten Rechenregeln.
Die BAM bearbeitet ein durch das UBA gefördertes Forschungsprojekt zur Erfassung und Bewertung von Analysedaten zu Aschen und Schlacken aus Abfallverbrennungsanlagen. Die Ergebnisse des Vorhabens sollen bei der Weiterentwicklung des vorhandenen Konzeptes für eine bundeseinheitlichen Untersuchung und abfallrechtlichen Einordnung von Aschen und Schlacken aus deutschen Abfallverbrennungsanlagen unterstützend herangezogen werden. Im Vortrag werden Verfahren zur quantitativen Bestimmung der einstufungsrelevanten Verbindungen vorgestellt: 1.) der Praxisleitfaden von ITAD und IGAM, 2.) Methode basierend auf der Bioverfügbarkeit und 3.) Methode basierend auf Speziierungsanalyse.
Metarhizium robertsii DSM 1490 is a generalist entomopathogenic fungus.
The mechanisms of pathogenesis of such fungi in insects like termites are not completely understood. Here, we report the draft genome sequence, as sequenced on the Oxford Nanopore platform. The genome has a GC% of 47.82 and a size of 45,688,865 bp
Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was
found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism.
Fused filament fabrication (FFF) is a material extrusion-based technique often used in desktop 3D printers. Polymeric filaments are melted and are extruded through a heated nozzle to form a 3D object in layers. The extruder temperature is therefore a key parameter for a successful print job but also one of the main emission driving factors as harmful pollutants (e.g., ultrafine particles) are formed by thermal polymer degradation. The awareness of potential health risks has increased the number of emission studies in the past years. However, studies usually refer their calculated emission data to the printer set extruder temperature for comparison purposes. In this study, we used a thermocouple and an infrared camera to measure the actual extruder temperature and found significant temperature deviations to the displayed set temperature among printer models. Our result shows that printing the same filament feedstocks with three different printer models and with identical printer set temperature resulted in a variation in particle emission of around two orders of magnitude. A temperature adjustment has reduced the variation to approx. one order of magnitude. Thus, it is necessary to refer the measured emission data to the actual extruder temperature as it poses a more accurate comparison parameter for evaluation of the indoor air quality in user scenarios or for health risk assessments.
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 der Zulassungsrichtlinie für Schutzschichten im und durch den Fachbeirat vorgestellt werden.
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 der Zulassungsrichtlinie für Schutzschichten im und durch den Fachbeirat vorgestellt werden.
The roles of DHN melanin and the stress-activated MAP kinase in the rock inhabitant Knufia petricola
(2023)
Black fungi/yeasts exhibit high stress tolerance, yeast‑like or meristematic growth, and constitutive 1,8-dihydroxynaphthalene (DHN) melanin formation. Due to their slow growth, robust cell walls and the lack of sexual cycles and genetic tools, the underlying mechanisms of their phenotypic traits have remained largely unexplored. Using recently developed genetic tools, it is now possible to manipulate the genome of the rock-inhabiting model fungus Knufia petricola. Thus, gene functions and the cell biology of black fungi can be studied using CRISPR/Cas9-based genome editing and live-cell imaging with genetically encoded fluorescent proteins. Here, we are addressing the question to which extent constitutive pigment formation (melanin and carotenoids) and responses mediated by the stress-activated mitogen-activated protein (MAP) kinase contribute to the observed extremotolerance of K. petricola. The mutations of pks1, phs1 and both genes result in melanin-free (pink), carotenoid-free (black) and pigment-free (white) strains, respectively. The other putative melanogenic genes were identified in the genome, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Sak1 encoding the stress-activated MAP kinase was deleted in the wild-type and different pigment-deficient backgrounds. Growth of the obtained single, double and triple deletion mutants was tested by droplet tests on media supplemented with different stress-inducing agents. The Δsak1 mutants show slightly reduced growth rates even without environmental pressure and are hypersensitive to different stresses: e.g. osmotic, oxidative, membrane, pH and heat stress. Melanin-free Δsak1 mutants are more sensitive than black Δsak1 mutants to some but not all stress conditions, suggesting that melanin and the SAK1 pathway have complementary roles in protecting K. petricola from stress.
Iron is arguably the most essential metal in living organisms. For rock-inhabiting fungi its acquisition might be unconventional as they (1) tend to inhabit iron-deficient, oxygen-rich surfaces like marble monuments and solar panels and (2) produce the black, iron-adsorbing pigment melanin. We used a range of analytical methods, ongoing mineral dissolution experiments and gene deletion mutants of the model rock-inhabiting fungus Knufia petricola to figure out the mechanisms and substrate deteriorating effects of iron uptake by these organisms. To study both siderophore-mediated and reductive iron assimilation (RIA), genes like sidC, encoding a putative siderophore synthetase and ftr1 and fet3 encoding the subunits of an iron permease-oxidase were deleted.
At iron deficient conditions, growth of the wild type (WT) and ΔsidC mutant was similar, whereas growth of the Δftr1-fet3 mutant and the double mutant ΔsidC/Δftr1-fet3 was diminished and absent, respectively. We were not able to detect the siderophore of K. petricola and the WT and mutants were not able to grow at low concentrations of strong iron chelators. However, in a cross-feeding experiment, an overexpression strain of sidC allowed more growth of ΔsidC/Δftr1-fet3 on iron deficient medium than the WT, whereas the ΔsidC mutant could not do so at all. Compared to the WT, the sidC overexpression strain also withstood oxidative stress better and had a shorter lag time and higher growth rate. Combined, these results indicate that K. petricola relies more on RIA than siderophore-mediated uptake as it likely excretes low quantities of a primarily intracellular siderophore. Interestingly, Δftr1-fet3 had a higher iron content than the WT at iron deficient conditions. This difference disappeared upon deletion of melanin synthesis (Δpks1 vs. Δpks1/Δftr1-fet3): melanin-bound iron can likely not be used without RIA. K. petricola’s chelation incapacity implies a habitat free of competition for iron while offering us a mitigation strategy.
Cryomyces antarcticus – a cryptoendolithic black fungus endemic to Antarctica – is taxonomically classified in phylum Ascomycota, class Dothideomycetes incertae sedis. C. antarcticus has shown high capability to survive extreme environmental conditions like those found in space (ionizing radiation, vacuum, microgravity), thus fueling fundamental astrobiological questions like “searching for life beyond Earth” (Onofri et al. 2020, Extremophiles Astrobiol Model). Its extraordinary resilience has been attributed to the presence of thick, highly melanized cell walls, which may contain both DHN and DOPA melanins (Pacelli et al. 2020, Appl Microbiol Biotechnol). To better understand the contribution of DHN melanin to the overall resilience of C. antarcticus, we initially adopted chemicals e.g., tricyclazole to inhibit the DHN melanin synthetic pathway; however, these studies gave inconclusive results. Eventually, we decided to generate melanin-deficient mutants by genetic engineering. Using the genetic toolkit developed for the black fungus Knufia petricola (Voigt et al. 2020, Sci Rep; Erdmann et al. 2022, Front Fungal Biol), we designed a strategy for mutating the key enzyme (polyketide synthase)-encoding gene capks1 by transient delivery of Cas9 and capks1-specific sgRNA from AMA-containing plasmids and PCR-generated donor DNA i.e., resistance cassettes flanked by ~75-bp-long sequences homologous to capks1. For this, the melanin-PKS encoding ortholog was identified in the C. antarcticus CBS 116301 genome (mycocosm.jgi.doe.gov) and used to design primers for re-sequencing of the capks1 locus in the strain CCFEE 515. Transformation of C. antarcticus is challenging because of its very slow growth; we expect that 4-6 months are needed from obtaining enough biomass for cell wall lysis until transferring putatively resistant transformants for genotyping. Important parameters were evaluated: protoplasts can be generated, and they survive the transformation procedure, and suitable concentrations of selective agents have been identified. Nowadays, we are waiting for the first C. antarcticus mutants considered to be deficient in DHN melanogenesis.
Microcolonial black fungi ubiquitously inhabit sun-exposed natural and man-made surfaces of our planet. To promote genetic studies, which are hindered by slow growth, lack of sexual cycles and transformation difficulties, CRISPR/Cas9-based genetic tools were implemented (Erdmann et al. 2022, Front Fungal Biol). Now efficient targeted mutagenesis of the rock inhabitant Knufia petricola (Eurotiomycetes/Chaetothyriales) - as a representative of the polyphyletic group of black fungi - enables the elucidation of extremotolerance, oligotrophism, unusual types of cell division, mineral weathering and symbiotic interactions. Still more progress on assigning functions to yet unknown genes can be expected if a forward genetics approach is available. We chose the two-component Activator/ Dissociation (Ac/Ds) transposon system from maize for generating a collection of insertional mutants by in-vivo mutagenesis of K. petricola. For the optimal use of this genetic tool, an inducible promoter for the expression of the Ac transposase (AcTPase) and by this the regulatable transposition of the resistance cassette-containing Ds transposon is desired. However, endogenous promoters for nitrate assimilation and galactose catabolism - often used in fungi for regulatable gene expression - are not inducible by their substrates in K. petricola suggesting that the regulatory networks for nutrient acquisition differ significantly in oligotrophic fungi. Therefore, the metabolism-independent Tet-on system was combined with the AcTPase coding sequence and subsequently transformed into Ds-carrying K. petricola strains. In total, four auxotrophic Ac|Ds starter strains containing the Ds transposon at different position of ade2 or ura3 were generated. The cultivation of these strains with doxycycline for induction of TET::Ac and subsequent selection of cells on ADE/URA-lacking media resulted in prototrophic colonies (revertants) for some but not all Ac|Ds strains. Currently, the transposition events in the obtained revertants are studied to validate the procedure. First amplicon sequencing of excision sites revealed footprint patterns, proving the transposon jumped.
DHN (1,8-dihydroxynaphthalene) melanin is produced by Ascomycetes via slightly differing synthetic routes. Polyketide synthases release YWA1, AT4HN or T4HN. YWA1 and AT4HN are deacetylated by ‘yellowish-green’ hydrolases, and T4HN is converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases. The melanogenic genes are tightly, partially or not clustered in the genomes, and are often regulated in a spatial and/or temporal fashion. By contrast, microcolonial fungi/black yeasts – a polyphyletic group of Ascomycetes dwelling in hostile habitats such as bare rock surfaces – feature constitutive DHN melanogenesis. Here, we report on the DHN melanogenic genes of Knufia petricola (Eurotiomycetes/Chaetothyriales).
In industrialised countries more than 80% of the time is spent indoors. Products, such as building materials and furniture, emit volatile organic compounds (VOCs), which are therefore ubiquitous in indoor air. Different VOC combinations may, under certain environmental and occupational conditions, result in reported sensory irritation and health complaints. A healthy indoor environment can be achieved by controlling the sources and by eliminating or limiting the release of harmful substances into the air. One way is to use materials proven to be low emitting. Meanwhile, a worldwide network of professional commercial and non-commercial laboratories performing emission tests for the evaluation of products for interior use has been established. Therefore, comparability and metrological traceability of test results must be ensured. A laboratory’s proficiency can be proven by internal and external validation measures that both include the application of suitable reference materials. The emission test chamber procedure according to EN 16516 comprises several steps from sample preparation to sampling of test chamber air and chromatographic analysis. Quality assurance and quality control (QA/QC) must therefore be ensured. Currently, there is a lack of suitable reference products containing components relevant for the health-related evaluation of building products.
The EU-funded EMPIR project 20NRM04 MetrIAQ (Metrology for the determination of emissions of dangerous substances from building materials into indoor air) aims to develop 1) gaseous primary reference materials (gPRM), which are used for the certification of gaseous (certified) reference materials (gCRM) and 2) emission reference materials (ERM).
Most commercial gas standards of indoor-relevant compounds are not certified due to the lack of primary reference materials to which the project aims to contribute. The gPRM under development is a gas-phase standard containing trace levels of VOCs in nitrogen or air from the check standard according to EN 16516 (n-hexane, methyl isobutyl ketone, toluene, butyl acetate, cyclohexanone, o-xylene, phenol, 1,3,5-trimethylbenzene) with a target uncertainty of 5 %. The gPRM can be sampled into sorbent tubes to obtain transfer standards in the form of gCRM.
The well characterised ERM represents a sample of a test specimen, e.g. building material, that is loaded into the emission test chamber for a period of several days and is used to evaluate the whole emission test chamber procedure. It shall have a reproducible and temporally constant compound release of less than 10 % variability over 14 days. Different approaches for retarded VOC release, such as the encapsulation of pure compounds and the impregnation of porous materials, are being tested to reach this aim. Furthermore, the design of the ERM is accompanied by the development of a numerical model for the prediction of the emissions for each of the target VOCs. The current progress of the work on both materials will be presented.
In 2005, a team of Polish archaeologists discovered three Coptic codices, two on papyrus and one on parchment, in the rubbish dump of a hermitage at Sheik Abd el-Gurna, Egypt. While the parchment codex and the remains of the bindings of the papyrus ones have been conserved, the text blocks of the papyrus codices were opened and disassembled and after being disinfected remained untouched for nearly 15 years, until the current project started. Currently, all three books are stored in the collection of the Coptic Museum in Cairo. Our team undertook the conservation of and archaeometric research on the papyrus codices. The first of the books contains the Canons of Pseudo-Basil, while the second is an Encomium of St. Pisenthios. Both codices have been palaeographically dated to the seventh-eighth centuries CE. In this paper, we describe our project and present the results of the work carried out on the Canons of Pseudo-Basil. Our work involved photography in transmitted light, measurements of the thickness of the papyrus leaves, and digital microscopy under three-light illumination. These measurements allowed us to determine the types of the inks and characterize the papyrus writing substrate. For conservation, we used a novel method developed in the Egyptian Museum in Berlin that comprises suspending papyrus folios on a translucent, extremely thin Japanese paper inside glass frames without the use of adhesives.In 2005, a team of Polish archaeologists discovered three Coptic codices, two on papyrus and one on parchment, in the rubbish dump of a hermitage at Sheik Abd el-Gurna, Egypt. While the parchment codex and the remains of the bindings of the papyrus ones have been conserved, the text blocks of the papyrus codices were opened and disassembled and after being disinfected remained untouched for nearly 15 years, until the current project started. Currently, all three books are stored in the collection of the Coptic Museum in Cairo. Our team undertook the conservation of and archaeometric research on the papyrus codices. The first of the books contains the Canons of Pseudo-Basil, while the second is an Encomium of St. Pisenthios. Both codices have been palaeographically dated to the seventh-eighth centuries CE. In this paper, we describe our project and present the results of the work carried out on the Canons of Pseudo-Basil. Our work involved photography in transmitted light, measurements of the thickness of the papyrus leaves, and digital microscopy under three-light illumination. These measurements allowed us to determine the types of the inks and characterize the papyrus writing substrate. For conservation, we used a novel method developed in the Egyptian Museum in Berlin that comprises suspending papyrus folios on a translucent, extremely thin Japanese paper inside glass frames without the use of adhesives.
Microscopic knowledge of the structural, energetic, and electronic properties of scandium fluoride is still incomplete despite the relevance of this material as an intermediate for the manufacturing of Al−Sc alloys. In a work based on first-principles calculations and X-ray spectroscopy, we assess the stability and electronic structure of six computationally predicted ScF3 polymorphs, two of which correspond to experimentally resolved single-crystal phases. In the theoretical analysis based on density functional theory (DFT), we identify similarities among the polymorphs based on their formation energies, chargedensity distribution, and electronic properties (band gaps and density of states). We find striking analogies between the results obtained for the ow- and high-temperature phases of the material, indirectly confirming that the transition occurring between them mainly consists of a rigid rotation of the lattice. With this knowledge, we examine the X-ray absorption spectra from the Sc and F K-edge contrasting firstprinciples results obtained from the solution of the Bethe−Salpeter equation on top of all-electron DFT with high-energy-resolution fluorescence detection measurements. Analysis of the computational results sheds light on the electronic origin of the absorption maxima and provides information on the prominent excitonic effects that characterize all spectra. A comparison with measurements confirms that the sample is mainly composed of the high- and low-temperature polymorphs of ScF3. However, some fine details in the experimental results suggest that the probed powder sample may contain defects and/or residual traces of metastable polymorphs.
The soil-feeding habit is an evolutionary novelty found in some advanced groups of termites. The study of such groups is important to revealing interesting adaptations to this way-of-life. The genus Verrucositermes is one such example, characterized by peculiar outgrowths on the head capsule, antennae and maxillary palps, which are not found in any other termite. These structures have been hypothesized to be linked to the presence of a new exocrine organ, the rostral gland, whose structure has remained unexplored.
We have thus studied the ultrastructure of the epidermal layer of the head capsule of Verrucositermes tuberosus soldiers.We describe the ultrastructure of the rostral gland, which consists of class 3 secretory cells only. The dominant secretory organelles comprise rough endoplasmic reticulum and Golgi apparatus, which provide secretions delivered to the surface of the head, likely made of peptide-derived components of unclear function. We discuss a possible role of the rostral gland of soldiers as an adaptation to the frequent encounter with soil pathogens during search for new food resources.
Pseudomonas aeruginosa is an opportunistic pathogen of considerable medical importance, owing to its pronounced antibiotic tolerance and association with cystic fibrosis and other life-threatening diseases. The aim of this study was to highlight the genes responsible for P. aeruginosa biofilm tolerance to antibiotics and thereby identify potential new targets for the development of drugs against biofilm-related infections. By developing a novel screening approach and utilizing a public P. aeruginosa transposon insertion library, several biofilm-relevant genes were identified. The Pf phage gene (PA0720) and flagellin gene (fliC) conferred biofilm-specific tolerance to gentamicin. Compared with the reference biofilms, the biofilms formed by PA0720 and fliC mutants were completely eliminated with a 4-fold-lower gentamicin concentration. Furthermore, the mreC, pprB, coxC, and PA3785 genes were demonstrated to play major roles in enhancing biofilm tolerance to gentamicin. The analysis of biofilm-relevant genes performed in this study provides important novel insights into the understanding of P. aeruginosa antibiotic tolerance, which will facilitate the detection of antibiotic resistance and the development of antibiofilm strategies against P. aeruginosa.
Colours on East Asian Maps
(2023)
Maps and colours have a close connection. Drawn or printed in black on white, subsequently added colours enhance maps with additional information. Colours were not just there to improve maps aesthetically, but they regulated how they were read and thus reinforced their meanings, significances and ideas. Colour is an important key to a more precise understanding of the map’s purposes and uses; moreover, colours are also an important aspect of a map’s materiality. The material scientific analysis makes it possible to find out more about the making of colours and the process of colouring maps. By skillfully deploying colours, map colourists were able to create mimetic representations of nature or codify information in an abstract form. The use of colours involved many considerations as to the materials. ‘Reading’ colours in this way gives a glimpse into the social lives of mapmakers as well as map users and reveals the complexity of the historical and social context in which maps were produced and how the maps were actually made. Within the scope of the three-year joint research project Coloured Maps (2018–2021), we undertook an in-depth and systematic study of hand-drawn and hand-coloured maps from East Asia in the Museum am Rothenbaum (MARKK) in Hamburg and produced between the seventeenth and twentieth centuries.
With a multi-perspective approach and transdisciplinary methods (humanities and the sciences), we were able to pool and compare the research results from different fields of research on Asian maps. The aim of this publication is to provide a first general overview of the subject of colours on maps in East Asia in the period from the seventeenth to the early twentieth century and to stimulate further research on the topic.
Ratiometric green–red fluorescent nanosensors for fluorometrically monitoring pH in the acidic range were designed from 80 nm-sized polystyrene (PS) and silica (SiO2) nanoparticles (NPs), red emissive reference dyes, and a green emissive naphthalimide pH probe, analytically and spectroscopically characterized, and compared regarding their sensing performance in aqueous dispersion and in cellular uptake studies. Preparation of these optical probes, which are excitable by 405 nm laser or LED light sources, involved the encapsulation of the pH-inert red-fuorescent dye Nile Red (NR) in the core of self-made carboxylated PSNPs by a simple swelling procedure and the fabrication of rhodamine B (RhB)-stained SiO2-NPs from a silane derivative of pH-insensitive RhB. Subsequently, the custom-made naphthalimide pH probe, that utilizes a protonation-controlled photoinduced electron transfer process, was covalently attached to the carboxylic acid groups at the surface of both types of NPs. Fluorescence microscopy studies with the molecular and nanoscale optical probes and A549 lung cancer cells confirmed the cellular uptake of all probes and their penetration into acidic cell compartments, i.e., the lysosomes, indicated by the switching ON of the green naphthalimide fluorescence. This underlines their suitability for intracellular pH sensing, with the SiO2-based nanosensor revealing the best performance regarding uptake speed and stability.
The chemical state of antimony and vanadium species in municipal solid waste incineration bottom ash
(2023)
Due to the large quantity as residual mineral waste, municipal solid waste incineration - bottom ash (MSWI-BA) is an interesting secondary raw material that can be utilized for road construction. However, leaching of chloride, sulfate and potentially hazardous heavy metals from MSWSI-BA into the environment may cause problems in utilization of it in civil engineering. In a previous study, we performed a long-term leaching test of MSWI-BA in a lysimeter for almost six years to investigate the efficiency of the treatment process on the release of hazardous substances. While concentrations of chloride, sulfate and the majority of the heavy metals started to decrease rapidly with progressive liquid-to-solid ratio (L/S), the ecotoxic hazardous elements antimony (Sb) and vanadium (V) behaved differently. To unravel these unusual release behaviors and the oxyanion-formation of Sb and V we will apply HERFD-XANES spectroscopy to analyze their chemical state.
The release of hazardous compounds from construction products can harm human health and the environment. To improve the sustainability of construction materials, the leaching of substances from construction products and their potential environmental impact should be assessed. Twenty-seven construction products from different product groups were examined with a combination of standardized leaching tests (dynamic surface leaching test and percolation test) and biotests (algae, daphnia, fish egg, luminescent bacteria, umu and Ames fluctuation tests). To identify the released substances, extensive qualitative and quantitative chemical analyses were performed, including gas chromatographic and liquid chromatographic screening techniques.
Results: Many of the tested eluates caused signifcant ecotoxic efects. Particularly high ecotoxicities were observed for grouts (lowest ineffective dilution (LID) up to 16384) and cork granules (LID up to 24578). The results of ecotoxicity tests allow the prioritization of the eluates that should be subjected to detailed chemical analyses. Organic screening by different methods and ranking the identifed substances based on recorded hazard classification is a suitable approach to identify the relevant toxic substances.
Conclusions: Determining the ecotoxicity of eluates from construction products records the summary effect of all leachable substances. This instrument is especially useful for construction products of complex and largely unknown composition. The ecotoxicological and the chemical–analytical approach complement each other in an ideal way to characterize the potential hazard of eluates from construction products and to identify the environmentally hazardous components in these eluates. Our results confirm that the proposed harmonized methods for testing eluate toxicity are an adequate and applicable procedure to move toward a more sustainable way of building and to reduce toxic effects of construction products in their use phase in the environment.
Der Vortrag widmet sich der materialwissenschaftlichen Analyse von Zeichnungen einiger Bauhausschülerinnen und Bauhausschüler und legt besonderen Fokus auf die verwendeten Farbmittel. Die Objekte werden mit nicht-invasiven bildgebenden Verfahren untersucht, in dem die Wechselwirkung zwischen Röntgen-, sichtbarem und infraroten Licht und den Zeichnungen studiert wird.
Dier Analysen liefern nicht nur generell Erkenntnisse über die Art und Zusammensetzung und damit das Alter der verwendeten Farbmittel. Durch die Auffindung von Vorzeichnungen, die Bestimmung von Überarbeitungen und Korrekturen werden Erkenntnisse über die Genese von Zeichnungen gewonnen. Auf der Basis dieser materialwissenschaftlichen Erkenntnisse werden die Begriffe Original, Kopie, Fälschung diskutiert.
Da die nicht-invasiven Untersuchungen einen umfassenden Einblick in die Materialität der – überwiegend aus Papier bestehenden – Objekte erlauben, bilden sie die Grundlage für die Erstellung nachhaltiger Konservierungs- und Restaurierungskampagnen und deren dauerhaften Erhalt.
The most massive design on the Baltic shore used geosynthetic materials, the landslide protection construction in Svetlogorsk (1300 m long, 90,000 m2 area, South-Eastern Baltic, Kaliningrad Oblast, Russian Federation) comprises the geotextile and the erosion control geomat coating the open-air cliff slopes. Due to changes in elastic properties during long-term use in the open air, as well as due to its huge size, this structure can become a non-negligible source of microplastic pollution in the Baltic Sea. Weather conditions affected the functioning of the structure, so it was assessed that geosynthetic materials used in this outdoor (open-air) operation in coastal protection structures degraded over time. Samples taken at points with different ambient conditions (groundwater outlet; arid places; exposure to the direct sun; grass cover; under landslide) were tested on crystallinity and strain at break. Tests showed a 39–85% loss of elasticity of the polymer filaments after 3 years of use under natural conditions. Specimens exposed to sunlight are less elastic and more prone to fail, but not as much as samples taken from shaded areas in the grass and under the landslide, which were the most brittle.
Throughout their life cycles—from production, usage, through to disposal—materials and products interact with the environment (water, soil, and air). At the same time, they are exposed to environmental influences and, through their emissions, have an impact on the environment, people, and health. Accelerated experimental testing processes can be used to predict the long-term environmental consequences of innovative products before these actually enter the environment.
We are living in a material world. Building materials, geosynthetics, wooden toys, soil, nanomaterials, composites, wastes and more are research subjects examined by the authors of this book. The interactions of materials with the environment are manifold. Therefore, it is important to assess the environmental impact of these interactions. Some answers to how this task can be achieved are given in this Special Issue.
The fungus Botrytis cinerea (Botryotinia fuckeliana) infects more than 500 plant species and causes a wide range of symptoms: soft rots, accompanied by collapse and water-soaking of tissues followed by the appearance of gray masses of conidia on leaves and soft fruits (gray mold), and spots that may turn brown to full-scale soft rotting on flower petals (Botrytis blight). In general, B. cinerea is responsible for severe economic losses that are either due to the damage of growing plants in the field or the rot of harvested fruits, flowers, and vegetables during storage under cold and humid conditions. B. cinerea has adapted to the plant host and its environment by evolving strategies to use plant tissues for proliferation in terms of a necrotrophic lifestyle, and to survive biotic stresses (host responses) as well as abiotic factors of the host’s environment such as sunlight and concomitant stresses. B. cinerea maintains a complex regulatory network of light-sensitive proteins and signal transduction pathways to use light for coordinating stress responses, virulence, and reproduction. Different light-controlled reproduction cycles enable B. cinerea to live in moderate climate zones by infecting and propagating in summer and resting in winter when green host tissues are unavailable.
EN 16516 sets specifications for the determination of emissions into indoor air from construction products. Reliable, accurate and International System of Unit (SI)-traceable measurement results of the emissions are the key to consumer protection. Such measurement results can be obtained by using metrologically traceable reference materials. Gas-phase standards of volatile organic compounds (VOCs) in air can be prepared by a variety of dynamic methods according to the ISO 6145 series. However, these methods are not always applicable for semi-VOCs (SVOCs) due to their high boiling point and low vapour pressure. Therefore, a novel dynamic gas mixture generation system has been developed. With this system gas-phase standards with trace level VOCs and SVOCs in air can be prepared between 10 nmol mol−1 and 1000 nmol mol−1. The VOCs and SVOCs in this study have normal boiling points ranging from 146 °C to 343 °C. Metrologically traceable reference materials of the gas-phase standard were obtained by sampling of the VOC gas-phase standard into Tenax TA® sorbent material in SilcoNert® coated stainless steel tubes. Accurately known masses between 10 ng and 1000 ng per VOC were sampled. These reference materials were used to validate the dynamic system. Furthermore, the storage and stability periods of the VOCs in the reference materials were determined as these are crucial characteristics to obtain accurate and SI-traceable reference materials. In a round robin test (RRT), the reference materials were used with the aim of demonstrating the feasibility of providing SI-traceable standard reference values for SVOCs for interlaboratory comparison purposes. Based on the results from the validation, the storage and stability studies and the RRT, gas-phase standards and reference materials of VOCs and SVOCs with relative expanded uncertainties between 5% and 12% (k = 2) have been developed. These reference standards can be used as calibrants, reference materials or quality control materials for the analysis of VOC emissions.
The ISO 16000-6 standard gives directions to adapt the analysis of volatile organic compounds (VOCs) in indoor and test chamber air to very volatile organic compounds (VVOCs). The same techniques with sorbent-based active sampling, thermal desorption and gas chromatography coupled with mass spectrometry (TD-GC/MS) should be used. However, VVOCs require gaseous standards, an adapted GC column and a reliable sampling adsorbent. This work presents experimental results to tackle those three experimental gaps. A stable standard gas mixture containing 47 VVOCs, 13 VOCs and an internal standard was successfully generated. It was employed to study the suitability of seven types of chromatography columns. The use of PLOT (Porous Layer Open Tubular) columns such as PoraBOND Q is well suitable for VVOC analysis. The recoveries of the 60 analytes on a total of 16 adsorbents and their combinations were determined: A combination of the graphitized carbon black Carbograph 5TD 40/60 and the carbon molecular sieve CarbosieveTM SII showed great recoveries for all analytes. Carbon molecular sieves adsorb water which can impair the analysis. A dry purge of the multi-sorbent in the sampling direction led to a complete water removal and promising recoveries of the analytes.