4 Material und Umwelt
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The Microplastic Microbiome
(2024)
Microplastics represent man-made and newly emerging surfaces in our ecosystems, where they interact with microorganisms. The ecosystem in focus of this presentation will be the aquatic environment. It will be portrayed, which microorganisms use microplastics as a habitat, how environmental factors shape this colonization, and why the biodegradation of plastics in the ocean is an overall unlikely process. We will also discuss whether potentially pathogenic microorganisms use microplastics as a raft. Finally, possible adaptation mechanisms of plastic-colonizing microorganisms will be presented, such as the production of photoreactive molecules. The microplastic microbiome has a large potential to harbor so far unknown species with curious traits, representing an exciting research topic for the future.
In this study, we investigated the diverse range of materials used for sizing in Iranian paper manuscripts during the Timurid (fifteenth century) to Safavid (sixteenth century) and Qajar (nineteenth century) periods. Our approach combined historical analysis with scientific examination of reconstructed sizings. We reconstructed 15 sizing materials based on identified Persian historical recipes and analysed their physical, optical, and spectral characteristics. Additionally, we assessed their behaviour against the mould fungus Aspergillus flavus. The results revealed distinctive properties for each sizing material, shedding light on their potential applications in paper preservation. Furthermore, our investigation demonstrated variations in hygroscopicity, thickness, grammage, and ash content post-sizing. The sizing materials also exhibited different effects on paper reflectance properties. Additionally, our study revealed insights into the impact of sizing on burnished papers, indicating that the mechanical process of burnishing did not significantly alter the chemical composition or spectral properties of the paper, with only minor changes in brightness observed in specific cases. All tested sizing materials supported varying levels of mould growth, indicating potential implications for paper conservation. Our findings provide valuable insights into the historical practices of Iranian paper sizing and offer practical considerations for the preservation of paper manuscripts.
Understanding Stimulation of Conjugal Gene Transfer by Nonantibiotic Compounds: How Far Are We?
(2024)
A myriad of nonantibiotic compounds is released into the environment, some of which may contribute to the dissemination of antimicrobial resistance by stimulating conjugation. Here, we analyzed a collection of studies to (i) identify patterns of transfer stimulation across groups and concentrations of chemicals, (ii) evaluate the strength of evidence for the proposed mechanisms behind conjugal stimulation, and (iii) examine the plausibility of alternative mechanisms. We show that stimulatory nonantibiotic compounds act at concentrations from 1/1000 to 1/10 of the minimal inhibitory concentration for the donor strain but that stimulation is always modest (less than 8-fold). The main proposed mechanisms for stimulation via the reactive oxygen species/SOS cascade and/or an increase in cell membrane permeability are not unequivocally supported by the literature. However, we identify the reactive oxygen species/SOS cascade as the most likely mechanism. This remains to be confirmed by firm molecular evidence. Such evidence and more standardized and high-throughput conjugation assays are needed to create technologies and solutions to limit the stimulation of conjugal gene transfer and contribute to mitigating global antibiotic resistance.
Microbially induced carbonate precipitation (MICP), a widespread phenomenon in nature, is gaining attention as a low-carbon alternative to ordinary Portland cement (OPC) in geotechnical engineering and the construction industry for sustainable development. In the Philippines, however, very few works have been conducted to isolate and identify indigenous, urease-producing (ureolytic) bacteria suitable for MICP. In this study, we isolated seven, ureolytic and potentially useful bacteria for MICP from marine sediments in Iligan City. DNA barcoding using 16s rDNA identified six of them as Pseudomonas stutzeri, Pseudomonas pseudoalcaligenes, Bacillus paralicheniformis, Bacillus altitudinis, Bacillus aryabhattai, and Stutzerimonas stutzeri but the seventh was not identified since it was a bacterial consortium. Bio-cementation assay experiments showed negligible precipitation in the control (without bacteria) at pH 7, 8, and 9. However, precipitates were formed in all seven bacterial isolates, especially between pH 7 and 8 (0.7–4 g). Among the six identified bacterial species, more extensive precipitation (2.3–4 g) and higher final pH were observed in S. stutzeri, and B. aryabhattai, which indicate better urease production and decomposition, higher CO2 generation, and more favorable CaCO3 formation. Characterization of the precipitates by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) confirmed the formation of three carbonate minerals: calcite, aragonite, and vaterite. Based on these results, all six identified indigenous, ureolytic bacterial species from Iligan City are suitable for MICP provided that the pH is controlled between 7 and 8. To the best of our knowledge, this is the first report of the urease-producing ability and potential for MICP of P. stutzeri, P. pseudoalcaligenes, S. stutzeri, and B. aryabhattai.
Per- and polyfluoroalkyl substances (PFAS) were classified as a group of highly concerning chemicals over the last decades. Because of the high persistence of PFAS, their previous use led to contamination of the environment and human population. Due to ongoing use and incomplete remediation or destruction methods, the PFAS background in the environment is growing continuously.
The presence of ultrashort PFAS (with ≤3 carbon atoms) in the environment is often overlooked despite their contributions to PFAS levels. These compounds may directly contaminate the environment and arise from degradation of polyfluorinated compounds as well as incomplete PFAS destruction in certain industrial processes. Nonetheless, few approaches for targeted analysis of ultrashort PFASs have been developed, except for trifluoroacetic acid (TFA). Beside liquid (LC-MS/MS), supercritical fluid (SFC-MS/MS), and ion chromatography (IC-MS)-based systems, gas chromatography coupled with mass spectrometry (GC-MS) is a promising method for detection and quantification of ultrashort PFAS.
The goal of this study was to develop a simple headspace GC-MS method for the quantification of ultrashort perfluorocarboxylic acids (PFCAs) and polyfluorinated alcohols (PFOHs) in water samples. In contrast to PFOHs, functionalization of PFCAs was required for quantification. This was done by esterification with methanol at 80 °C, which can be carried out directly in the headspace GC-MS system.
Moreover, several parameters were optimized to achieve a low limit of quantification (LOQ) for the analytes used: i) The ratio of the aqueous solution, methanol, and available gas phase within the analysis vessel, ii) the concentration of additional acid in esterification mixtures of PFCAs, iii) shaking frequency and iv) shaking time before analysis. After optimizing the procedure, we were able to quantify ultrashort PFCAs and PFOHs. Thus, our developed headspace GC-MS method has the potential to be used as an alternative target analysis for ultrashort-chain PFCAs and PFOHs in various water samples (groundwater, wastewater).
Following the recommendation of the European Chemicals Agency, on 25 September 2023 the European Commission passed a comprehensive new regulation to reduce emissions of microplastics (MP) into the environment, which includes the sale and use of intentionally added MP.1,2 This also applies to the application of synthetic rubber granulate infill in artificial turf systems and will ultimately have an impact on recreational sports. In Germany, rubber granulate made of ethylene-propylene-diene-monomer rubber (EPDM) is currently predominantly used. So far, there is no sufficient database for estimating MP emissions from artificial turf pitches into the environment and thus their relevance as a source of MP pollution.3 This topic is controversially discussed due to the complexity of sampling and analytics. To close this research gap, this project has the goal to determine mass balances for the emissions of MP from artificial turf pitches to allow an estimation of the amount of MP released per artificial turf pitch and year.
Within this study, MP emissions of three artificial turf scenarios at different time states (unaged, artificially aged and real-time aged) are compared: the past (old turf: fossil based, synthetic infill), present (most commonly installed in Europe: fossil based, EPDM infill), and the future (turf with recycled gras fibres, no synthetic infill). To simulate the outdoor weathering during the lifespan of an artificial turf of approx. 15 years, brand-new artificial turf and EPDM rubber granulate were accelerated aged by means of UV weathering and mechanical stress. Potential MP emissions into surface and groundwater are simulated by lysimeter and shake experiments. MP mass contents are subsequently determined by Thermal Extraction Desorption Gas Chromatography/Mass Spectrometry. Using special microfilter crucibles allows the estimation of the particle sizes of the emitted MP, which is a fundamental requirement for an assessment of potential health hazards for humans.
Microbiologically influenced corrosion (MIC) is a crucial issue for industry and infrastructure. Biofilms are known to form on different kinds of surfaces such as metal, concrete, and medical equipment. However, in some cases the effect of microorganisms on the material can be negative for the consistency and integrity of the material. Thus, to overcome the issues raised by MIC on a system, different physical, chemical, and biological strategies have been considered; all having their own advantages, limitations, and sometimes even unwanted disadvantages. Among all the methods, biocide treatments and antifouling coatings are more common for controlling MIC, though they face some challenges. They lack specificity for MIC microorganisms, leading to cross-resistance and requiring higher concentrations. Moreover, they pose environmental risks and harm non-target organisms. Hence, the demand for eco-friendly, long-term solutions is increasing as regulations tighten. Recently, attentions have been directed to the application of nanomaterials to mitigate or control MIC due to their significant antimicrobial efficiency and their potential for lower environmental risk compared to the conventional biocides or coatings. Use of nanomaterials to inhibit MIC is very new and there is a lack of literature review on this topic. To address this issue, we present a review of the nanomaterials examined as a biocide or in a form of a coating on a surface to mitigate MIC. This review will help consolidate the existing knowledge and research on the use of nanomaterials for MIC mitigation. It will further contribute to a better understanding of the potential applications and challenges associated with using nanomaterials for MIC prevention and control.
The use of ashes from municipal solid waste incineration as secondary building materials is an important pillar for the circular economy in Germany. However, leaching of potential toxic elements from these materials must be at environmentally acceptable levels. Normally, a three-month ageing period immobilizes most hazardous heavy metals, but antimony (Sb) and vanadium (V) showed previously unusual leaching. In order to clarify the mechanisms, we analyzed the Sb and V species in various bottom and fly ashes from municipal waste incineration by XANES spectroscopy. Antimony oxidizes from Sb(+ III) species used as flame retardants in plastics to Sb(+ V) compounds during waste incineration. However, owing to the similarity of different Sb(+ V) compound in the Sb K- and L-edge XANES spectra, it was not possible to accurately identify an exact Sb(+ V) species. Moreover, V is mainly present as oxidation state + V compound in the analyzed ashes. However, the coarse and magnetic fraction of the bottom ashes contain larger amounts of V(+ III) and V(+ IV) compounds which might enter the waste incineration from vanadium carbide containing steel tools. Thus, Sb and V could be critical potential toxic elements in secondary building materials and long-term monitoring of the release should be taken into account in the future.
Investigation on the Durability of a Polypropylene Geotextile under Artificial Aging Scenarios
(2024)
Geosynthetics are widely used in various civil engineering applications, such as geotextiles in coastal protection, and display a sustainable alternative to natural mineral materials. However, the full benefits of using geosynthetics can only be gained with a long service lifetime of the products. With the use of added stabilizers to the polymers, service lifetimes can be achieved in the range of 100 years. Therefore, accelerated aging methods are needed for the assessment of the long-term performance of geotextiles. In the present study, the behavior of geosynthetic materials made of polypropylene was investigated under artificial aging conditions involving elevated temperatures ranging from 30 to 80 °C, increased oxygen pressures ranging from 10 to 50 bar in water-filled autoclaves, and UV irradiation under atmospheric conditions. ATR-IR spectroscopy was employed to detect the increase in the carbonyl index over various aging durations, indicating the oxidative degradation of the geotextile. The most pronounced increase was observed in the case of aging through UV irradiation, followed by thermal aging. Elevated pressure, on the other hand, had a lower impact on oxidation. High-temperature size exclusion chromatography was utilized to follow the reduction in molar mass under different degradation conditions, and the results were consistent with those obtained from ATR-IR spectroscopy. In polyolefins such as polypropylene, Hindered Amine Stabilizers (HAS) are used to suppress oxidation caused by UV radiation. The quantitative analysis of HAS was carried out using a UV/Vis method and HPLC. The degradation of UV stabilizers during the aging of geotextiles is responsible for the oxidation and the reduction in the molar mass of polypropylene. From the results, it can be concluded that applications of PP geotextile without soil or sand cover might cause the risk of the formation of microplastic particles. Material selection, design, and maintenance of the construction must follow best practices, including the system’s removal or replacement at end-of-life. Otherwise, a sustainable use of geotextiles in civil engineering is not possible.
Volatile organic compounds (VOCs) emitted by furniture and building materials can cause health issues. For an improvement of indoor air quality low emitting materials should be used. Quality assurance and –control (QA/QC) measures require an emission reference material (ERM) with a predictable emission rate of VOCs. The idea is to use porous materials as ERM, which store the VOCs inside their pores and emit them constantly.
Nowadays, people spend most of their time indoors. Thus, a good indoor air quality is important. Emissions of volatile organic compounds (VOCs) from furniture and building materials can cause health complaints1. Quantitative VOC-emission testing is carried out under standardized conditions in emission test chambers. In the presented project an emission reference material (ERM) is developed that emits a defined mixture of VOCs which is required for quality assurance and -control (QA/QC) measures. Porous materials (e.g zeolites, activated carbons, MOFs or aerogels) are used as reservoir materials and impregnated with VOC. The porous materials are selected, among others, by their pore size, pore size distribution, polarity and availability. Due to their regular pore structure zeolites are tested at first. For a prediction of the emission profile, the ERM is supposed to exhibit a constant emission rate over time. The aim is a stability of ≤ 10 % change in the emission rate over a minimum of 14 days.
Method
For impregnation, the material is placed into an autoclave inside a rotatable basket. The VOC is added and the autoclave is closed. Afterwards, CO2 is inserted. The closed system is then heated to the supercritical point of CO2 (31 °C, 73.75 bar). In this state, the CO2 acts as solvent for the VOC. By rotating the basket, the distribution of the VOC is ensured. After a few minutes, the pressure is decreased slowly and the CO2 is released. For the determination of the emission profile, the impregnated sample is placed into an emission test chamber. These chambers can be operated either with dry or humid air (50 ± 5 % rel. humidity). Every second to third day, air samples are taken and analyzed by gas chromatography. For an ideal impregnation, several different pressures and temperatures as well as impregnation times are tested.
Results
Two zeolite materials tested in dry air conditions reach emission profiles with a decrease of less than 10 % over 14 days (heptane and toluene, respectively). Further it was discovered that smaller pellets of the same zeolite show better results than bigger particles. When the pore size of a zeolite is too small, e.g. 0.3 nm, the VOC cannot be absorbed sufficiently. The main disadvantage of zeolites is their hygroscopicity because it has a large impact on the release of VOC when they are used in emission test chambers under standardized test conditions (23 °C, 50 % rel. humidity). Activated carbons have emission profiles with a larger change over 14 days. However, the high hydrophobicity allows measurements in humid air conditions which was not possible with the before mentioned hygroscopic zeolites. It is possible to impregnate powdered materials as well, and thus powdered non-hygroscopic (n.h.) zeolites were impregnated. Their emission profiles are comparable to those of the activated carbons. The use of methylated hygroscopic zeolites with a decrease in hygroscopicity did not yield successful emission measurements. The change over 14 days is calculated only for the stable phase (~250–300 h).
The desired stability of ≤ 10 % change of the emission rate over 14 days could already be reached under dry testing conditions. Further investigations under humid conditions show that zeolites with high Si/Al-ratios are non-hygroscopic and comparable to activated carbons (20–30 % change). The next step is to reduce the change in the emission rate of these materials to the aimed ≤ 10 % over 14 days.
The present work demonstrates a sustainable approach of using relatively coarser iron ore particles for ironmaking. The motivation is to reduce the energy consumption in the milling of the iron ore by utilizing coarser iron ore particles (+0.05 mm) and to select a suitable binder for improving pellet properties. Iron ore fines in the range of 0.05–0.25 mm was selected and classified into three size ranges. Fluxed iron ore pellets were prepared using lime as a binder for the basicity of 0, 1, and 2. Reduction of these pellets with a packed bed of coal fines was performed in the temperature range of 900–1200 °C for a duration of 30–120 min. The direct reduction kinetics of the iron ore pellets were studied by employing diffusion and chemical reaction control models to the experimental data. The results show that pellets made with coarser iron ore particles have improved reduction behavior and kinetics. The reduction reaction is found to be a mixed control. The activation energy for the reduction reaction varies from 44.3 to 74.76 kJ mol−1 as iron ore particle size decreases from 0.25 to 0.05 mm and basicity increases from 0 to 2.
Sunlight is an almost unavoidable environmental cue and plays a fundamental role in the biology of pro- and eukaryotic organisms. To cope with sunlight-associated stresses e.g., high temperatures, UV radiation with associated DNA damage, accumulation of reactive oxygen species (ROS), desiccation and osmotic stresses, it is important for organisms to accurately sense and respond to changes in light. The benefits of light are obvious for green organisms such as cyanobacteria, algae and plants which use light as an energy source (photosynthesis). Less apparent are other light-dependent processes such as light-driven DNA repair by photolyases (photoreactivation) or ion pumping by microbial opsins. Fungi that can share light-flooded habitats with phototrophs may profit from their excess photosynthetic products. Rock-inhabiting Dothideomycetes and Eurotiomycetes including Knufia petricola possess many proteins for absorbing UV/blue, green, red and far-red light, produce the black 1,8 dihydroxynaphthalene (DHN) melanin and orange-red carotenoids, and may live in multispecies biofilms. 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 light (UV-B) tolerance of K. petricola.
The emission of ultrafine particles from small desktop Fused Filament Fabrication (FFF) 3D printers has been frequently investigated in the past years. However, the vast majority of FFF emission and exposure studies have not considered the possible occurrence of particles below the typical detection limit of Condensation Particle Counters and could have systematically underestimated the total particle emission as well as the related exposure risks. Therefore, we comparatively measured particle number concentrations and size distributions of sub-4 nm particles with two commercially available diethylene glycol-based instruments – the TSI 3757 Nano Enhancer and the Airmodus A10 Particle Size Magnifier. Both instruments were evaluated for their suitability of measuring FFF-3D printing emissions in the sub-4 nm size range while operated as a particle counter or as a particle size spectrometer. For particle counting, both instruments match best when the Airmodus system was adjusted to a cut-off of 1.5 nm. For size spectroscopy, both instruments show limitations due to either the fast dynamics or rather low levels of particle emissions from FFF-3D printing in this range. The effects are discussed in detail in this article. The findings could be used to implement sub-4 nm particle measurement in future emission or exposure studies, but also for the development of standard test protocols for FFF-3D printing emissions.
Sunlight is an almost unavoidable environmental cue and plays a fundamental role in the biology of pro- and eukaryotic organisms. To cope with sunlight-associated stresses e.g., high temperatures, UV radiation, accumulation of reactive oxygen species, desiccation, and osmotic stress, it is important for organisms to accurately sense and respond to changes in light. The benefits of light are obvious for green organisms such as cyanobacteria, algae and plants which use light as an energy source (photosynthesis). Fungi that can share light-flooded habitats with phototrophs may profit from their excess photosynthetic products. Examples are the plant pathogen Botrytis cinerea, the gray mold fungus, and the rock inhabitant Knufia petricola, a microcolonial black fungus which forms multispecies biofilms with bacteria and algae.
Maintaining and modulating mechanical anisotropy is essential for biological processes. However, how this is achieved at the microscopic scale in living soft matter is not always clear. Although Brillouin light scattering (BLS) spectroscopy can probe the mechanical properties of materials, spatiotemporal mapping of mechanical anisotropies in living matter with BLS microscopy has been complicated by the need for sequential measurements with tilted excitation and detection angles. Here we introduce Brillouin light scattering anisotropy microscopy (BLAM) for mapping high-frequency viscoelastic anisotropy inside living cells. BLAM employs a radial virtually imaged phased array that enables the collection of angle-resolved dispersion in a single shot, thus enabling us to probe phonon modes in living matter along different directions simultaneously. We demonstrate a precision of 10 MHz in the determination of the Brillouin frequency shift, at a spatial resolution of 2 µm. Following proof-of-principle experiments on muscle myofibres, we apply BLAM to the study of two fundamental biological processes. In plant cell walls, we observe a switch from anisotropic to isotropic wall properties that may lead to asymmetric growth. In mammalian cell nuclei, we uncover a spatiotemporally oscillating elastic anisotropy correlated to chromatin condensation. Our results highlight the role that high-frequency mechanics can play in the regulation of diverse fundamental processes in biological systems. We expect BLAM to find diverse applications in biomedical imaging and material characterization.
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. VOC in combination may, under certain environmental and occupational conditions, result in reported sensory irritation and health complaints. Emission concentrations can become further elevated in new or refurbished buildings where the rate of air exchange with fresh ambient air may be limited due to improved energy saving aspects. 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 (building) materials proved 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 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 emission reference materials (ERM). For the emission test chamber procedure according to EN 16516, no artificial ERM is commercially available. The EU-funded EMPIR project MetrIAQ aims to fill this gap by developing new and improved ERMs. The goal is to obtain a material with a reproducible and temporally constant compound release (less than 10 % variability over 14 days). Two approaches were tested: the impregnation of porous materials with VOC, and the encapsulation of VOC in polymer microcapsules. Impregnation is performed with help of an autoclave and supercritical CO2. The encapsulation is done by interfacial polymerisation on VOC droplets. For both approaches, synthesis and/or material parameters were varied to obtain an optimal ERM. Findings about the optimisation of ERM generation, as well as performance of the best emission reference materials, will be presented.
Here, we show that calcium sulfate dihydrate (gypsum) can be directly, rapidly and reversibly converted to calcium sulfate hemihydrate (bassanite) in high salinity solutions (brines). The optimum conditions for the efficient production of bassanite in a short time (<5 min) involve the use of brines with c(NaCl) > 4 M and maintaining a temperature, T > 80 °C. When the solution containing bassanite crystals is cooled down to around room temperature, eventually gypsum is formed. When the temperature is raised again to T > 80 °C, bassanite is rapidly re-precipitated. This contrasts with the better-known behaviour of the bassanite phase in low-salt environments. In low-salinity aqueous solutions, bassanite is considered to be metastable with respect to gypsum and anhydrite, and therefore gypsum-to-bassanite conversion does not occur in pure water. Interestingly, the high-salinity transformation of gypsum-to-bassanite has been reported by many authors and used in practice for several decades, although its very occurrence actually contradicts numerical thermodynamic predictions regarding solubility of calcium sulfate phases. By following the evolution of crystalline phases with in situ and time-resolved X-ray diffraction/scattering and Raman spectroscopy, we demonstrated that the phase stability in brines at elevated temperatures was inaccurately represented in the thermodynamic databases. Most notably for c(NaCl) > 4 M, and T > 80 °C gypsum becomes readily more soluble than bassanite, which induces the direct precipitation of the latter from gypsum. The fact that these transformations are controlled by the solution provides extensive opportunities for precise manipulation of crystal formation. Our experiments confirmed that bassanite remained the sole crystalline phase for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
AbstractRed mud is the waste of bauxite refinement into alumina, the feedstock for aluminium production1. With about 180 million tonnes produced per year1, red mud has amassed to one of the largest environmentally hazardous waste products, with the staggering amount of 4 billion tonnes accumulated on a global scale1. Here we present how this red mud can be turned into valuable and sustainable feedstock for ironmaking using fossil-free hydrogen-plasma-based reduction, thus mitigating a part of the steel-related carbon dioxide emissions by making it available for the production of several hundred million tonnes of green steel. The process proceeds through rapid liquid-state reduction, chemical partitioning, as well as density-driven and viscosity-driven separation between metal and oxides. We show the underlying chemical reactions, pH-neutralization processes and phase transformations during this surprisingly simple and fast reduction method. The approach establishes a sustainable toxic-waste treatment from aluminium production through using red mud as feedstock to mitigate greenhouse gas emissions from steelmaking.
Fused cement clinker can be produced from molten basic oxygen furnace slag (BOFS) by way of a reductive thermochemical treatment. During the thermochemical treatment, oxidic iron is reduced to metallic iron and separated. The resulting low-iron slag has a chemical and mineralogical composition similar to ordinary Portland cement (OPC) clinker. In this study, the hydraulic reactivity of the fused clinker from BOFS with and without gypsum was investigated using isothermal calorimetry, differential scanning calorimetry, in situ X-ray diffraction and powder X-ray diffraction. Furthermore, a synthetic fused clinker without foreign ions and fused clinker produced by a mixture of both materials was studied. The hydraulic reaction of the fused clinker from BOFS was considerably slower than that of OPC. However, the reaction can be accelerated by adding gypsum as a sulfate carrier. Furthermore, the results showed an increased reaction rate with decreasing content of foreign ions such as Fe, P or Mn.