TY - JOUR A1 - Uhlig, S. A1 - Colson, B. A1 - Schoknecht, Ute T1 - A mathematical approach for the analysis of data obtained from the monitoring of biocides leached from treated materials exposed to outdoor conditions N2 - Leaching processes are responsible for the release of biocides from treated materials into the environment. Adequate modeling of emission processes is required in order to predict emission values in the framework of the risk assessment of biocidal products intended for long-term service life. Regression approaches have been applied to data obtained from the long-term monitoring of biocide emissions in experiments involving semi-field conditions. Due to the complex interaction of different underlying mechanisms such as water and biocide diffusion and desorption, however, these attempts have proven to be of limited usefulness e at least, for the available biocide emission data. It seems that the behavior of the biocide emission curve depends to a considerable extent on whichever underlying mechanism is slowest at a given point in time, thus limiting the amount of biocide available for release. Building on results obtained in the past few years, the authors propose a criterion for determining which mechanism controls the leaching process at a given point in time based on the slope of the log-log emission curve. In addition, a first-order approximation of this slope value is presented which displays advantages both in terms of computability and interpretability. Finally, an algorithm for the determination of breakpoints in the slope of the log-log emission curve is presented for the demarcation of phases within which one mechanism acts as a limiting factor. KW - Biocides KW - Leaching KW - Weathering KW - Mathematical analysis PY - 2019 DO - https://doi.org/10.1016/j.chemosphere.2019.04.102 SN - 0045-6535 SN - 1879-1298 VL - 228 SP - 271 EP - 277 PB - Elsevier AN - OPUS4-47886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Urbanczyk, M.M. A1 - Bester, K. A1 - Borho, N. A1 - Schoknecht, Ute A1 - Bollmann, U.E. T1 - Influence of pigments on phototransformation of biocides in paints N2 - Biocides are commonly applied to construction materials such as facade renders and paints in order to protect them from microbial spoilage. These renders and paints are exposed to weathering conditions, e.g., sunlight and rain. Pigments are interacting intensively with the spectrum of the incoming light; thus, an effect of paint pigments on phototransformation rates and reaction pathways of the biocides is hypothesized. In this study, the phototransformation of four commonly used biocides (carbendazim, diuron, octylisothiazolinone (OIT) and terbutryn) in four different paint formulations differing solely in pigments (red and black iron oxides, white titanium dioxide, and one pigment-free formulation) were investigated. Paints surfaces were irradiated under controlled conditions. The results show that biocides degrade most rapidly in the pigment-free formulation. The degradation in the pigment-free formulation followed a first-order kinetic model with the respective photolysis rate constants: kp,Diuron=0.0090 h−1, kp,OIT=0.1205 h−1, kp,Terbutryn=0.0079 h−1. Carbendazim concentrations did not change significantly. The degradation was considerably lower in the pigment-containing paints. The determination of several phototransformation products of terbutryn and octylisothiazolinone showed different transformation product ratios dependent on the pigment. Consequently, pigments not only reflect the incoming light, but also interact with the biocide photodegradation. KW - OIT KW - Terbutryn KW - Indirect photolysis KW - Construction materials PY - 2019 DO - https://doi.org/10.1016/j.jhazmat.2018.10.018 SN - 0304-3894 VL - 364 SP - 125 EP - 133 PB - Elsevier AN - OPUS4-46328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Vandrich, Jasmina T1 - Metabolic engineering in Halomonas elongata N2 - Halomonas elongata is a halophilic γ-proteobacterium that synthesizes and accumulates the compatible solute ectoine to cope with osmotic stress in saline environments. Ectoine possesses protecting properties and stabilizes proteins as well as whole cells against stresses like ionizing radiation and cytotoxins. These properties make ectoine a highly demanded ingredient in cosmetics and pharmaceuticals. To date H. elongata is the industrial Producer strain of ectoine, but several metabolic factors for optimum ectoine production remain to be explored. In this work, we used up to date Metabolic engineering approaches following the ‘Push, Pull, Block – strategy’ to examine targets that contribute to ectoine synthesis. Firstly, the basics of glucose catabolism were inspected to PUSH and enhance carbon flow towards ectoine synthesis. Secondly, lysine biosynthesis was targeted to BLOCK a pathway that is competing for precursors with ectoine synthesis. Thirdly, the mechanosensitive (MS) channels of H. elongata have been examined as possible excretion routes for ectoine. An overexpression of the ectoine excretion channels potentially could PULL out product at the end of ectoine synthesis and increase overall ectoine flux. For the interrogation of central metabolic pathways, we established the new molecular tool CRISPR-mediated interference (CRISPRi) for targeted modulation of gene expression. PUSH Glucose catabolism through the Entner-Doudoroff (ED) and Emden-Meyerhof-Parnas (EMP) pathway was targeted with CRISPRi and examined on gene expression level for ist response to changing salinity and different carbon sources. Changing salinity did not influence gene expression levels of glucose catabolism but the carbon source glucose triggered glycolysis through the (ED) pathway. When gene expression of the ED pathway was downregulated with CRISPRi, the growth rates remained constant. The observations indicate a metabolic overflow mechanism for glycolysis, in which fluxes are constantly high - even at lower salinity when no resources are demanded for ectoine synthesis. The further analysis of glucose to product conversion rates will advise optimum conditions for future industrial cultivation processes. BLOCK Lysine biosynthesis was downregulated with CRISPRi, which led to a significant increase in ectoine production. Hence, the blockage of lysine biosynthesis would be a valuable strategy for the optimization of the industrial producer strain in future studies. PULL MS channels and ectoine regulation are inevitably connected in osmoadaptation. Therefore, ectoine excretion, growth performance and gene expression levels of the MS channels were monitored in steady state conditions and in response to osmotic shock in the wildtype strain and in a MS channel deletion mutant. We observed that the MS channels were essential for the survival of osmotic shock but surprisingly their presence reduced cell growth under high salinity. The MS channels were only partially responsible for ectoine excretion. Thus, alternative ectoine excretion channels must exist and remain to be explored. KW - Halomonas elongata KW - Ectoine KW - CRISPR dCas9 PY - 2019 SP - 1 EP - 94 CY - Potsdam AN - OPUS4-51094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Sekine, R. A1 - Steckenmesser, D. A1 - Steffens, D. A1 - Huthwelker, T. A1 - Borca, C. A1 - Adam, Christian T1 - Effect of Nitrification Inhibitor on Nitrogen Forms in Soil analyzed by Nitrogen K edge micro XANES Spectroscopy N2 - Specific co-fertilization of nutrients can enhance their plant-availability and thus the yield of plants. To investigate this effect, we performed a pot experiment with three different P-fertilizers and ammonium nitrate sulfate as a co-fertilizer, without and with a nitrification inhibitor (NI), and analyzed the form of nitrogen (N) in the soil via novel X-ray spectroscopic method. The application of NI with the N fertilizer led to a higher dry matter yield of maize. Novel N K-edge micro-X-ray absorption near-edge structure (micro-XANES) spectroscopy identified that the application of a NI promotes the temporary formation of a non-exchangeable N in detectable hot-spots in the soil. The subsequent slow release and prolonged availability of N during plant growth leads to higher yield. It can be concluded that NIs lead to a temporary fixation of ammonium-N in a pool that can be accessed by plant roots. Those types of available nutrient pools meet the idea of so-called “next generation fertilizers” as plants have access to nutrients according to their current demand. T2 - Workshop for X-ray and neutron imaging applications in soil sciences CY - Lund, Sweden DA - 17.06.2019 KW - Nitrogen KW - Phosphorus recycling KW - Fertilizer KW - XANES spectroscopy KW - Pot experiment PY - 2019 AN - OPUS4-48237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Sekine, R. A1 - Huang, J. A1 - Steckenmesser, D. A1 - Steffens, D. A1 - Huthwelker, T. A1 - Borca, C. A1 - Pradas del Real, A. A1 - Castillo-Michel, H. A1 - Adam, Christian T1 - Effect of Nitrification Inhibitor on Nitrogen Forms in Soil and Phosphorus Uptake of Plants N2 - Phosphorus (P) resource availability is declining and the efficiency of applied nutrients in agricultural soils is becoming increasingly important. This is especially true for P-fertilizers from recycled materials which often have a lower plant-availability compared to commercial P-fertilizers but are expected to play an increasingly important role into the future (Kratz et al. 2019). One promising way to increase the plant-availability of the fertilizer P is a co-fertilization with specific nitrogen (N) forms which can enhance the P uptake and make P-fertilizers from recycled material more competitive to commercial phosphate rock-based P-fertilizers (Rahmatullah et al. 2006; Vogel et al. 2018). To investigate this effect, we performed a pot experiment with three different P-fertilizers (sewage sludge-based, phosphate rock and triple superphosphate) and ammonium nitrate sulfate as a co-fertilizer, without and with a nitrification inhibitor (NI), and analyzed the form of N and P in soil via a suite of chemical and novel X-ray spectroscopic methods. The application of NI with the P and N fertilizers led to a higher dry matter yield and a higher P uptake of maize. Novel N K-edge micro-X-ray absorption near-edge structure (micro-XANES) spectroscopy identified that the application of a NI promotes the temporary formation of a non-exchangeable N in detectable hot-spots in the soil. The subsequent slow release and prolonged availability of N during plant growth leads to higher yield and nutrient uptake. It can be concluded that NIs lead to a temporary fixation of ammonium-N in a pool that can be accessed by plant roots. Those types of available nutrient pools meet the idea of so-called “next generation fertilizers” as plants have access to nutrients according to their current demand. T2 - Annual Meeting of the German Society of Plant Nutrition (DGP) CY - Berlin, Germany DA - 25.09.2019 KW - Fertilzer KW - X-ray adsorption near-edge structure (XANES) spectroscopy KW - Nitrification inhibitor KW - Agronomic performance PY - 2019 AN - OPUS4-49144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Krüger, O. A1 - Hoffmann, Marie A1 - Adam, Christian T1 - Determination of chromium(VI) in phosphorus fertilizers made from recycled materials by DGT N2 - Phosphorus (P) fertilizers from secondary resources became increasingly important in the last years. However, these novel P-fertilizer can also contain toxic pollutants e.g. chromium (Cr) in the hexavalent state (Cr(VI)), which is regulated with low limit values in agricultural products (German fertilizer ordinance limit: 2 mg/kg Cr(VI)). The determination of Cr(VI) in these novel fertilizer matrices can be hampered by redox processes that lead to false results with the standard wet chemical extraction method (German norm DIN EN 15192). Therefore, we analyzed Cr(VI) in various P-fertilizers with the DGT technique. DGT devices equipped with a APA (polyacrylamide) diffusion layer and Cr(VI) selective N-methyl-D-glucamine (NMDG) binding layer were used for the study. After a 24 h conditioning period of the fertilizer at 60% of the water holding capacity (WHC), the fertilizers were brought to 100% WHC, transferred onto the DGT devices and deployed for 24 h at 25°C. The extraction of Cr from the DGT binding layer was carried out with 1 M HNO3 for 24 h. The Cr-concentrations of the extract were determined by means of ICP-MS. We found a good correlation between the standard wet chemical extraction and the DGT method for the whole range of P-fertilizers. However, partly soluble Cr(VI) compounds cannot be detected in full extent by the DGT method that is best suited for mobile Cr(VI). Furthermore, Cr K-edge XANES spectroscopy showed that the Cr(VI)-selective DGT binding layer also adsorbs mobile Cr(III) compounds from acid treatment of phosphates which can therefore cause an overestimation of Cr(VI). The DGT method was very sensitive and in most cases selective for the analysis of Cr(VI) in P-fertilizers made from recycled materials. However, the results of certain types of P-fertilizers containing mobile Cr(III) or partly immobile Cr(VI) show that still some optimization of the method is required to avoid over- or underestimation of Cr(VI). T2 - 6th Conference on Diffusive Gradients in Thin Films CY - Vienna, Austria DA - 17.09.2019 KW - Fertilzer KW - Pollutant KW - Chromium KW - Diffusive gradients in thin films (DGT) KW - XANES spectroscopy PY - 2019 AN - OPUS4-49058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Huang, L. A1 - Sekine, R. A1 - Doolette, A. A1 - Herzel, Hannes A1 - Kugler, Stefan A1 - Hoffmann, Marie A1 - Lombi, E. A1 - Zuin, L. A1 - Wang, D. A1 - Félix, R. A1 - Adam, Christian T1 - Specification of bioavailable nutrients and pollutants in the environment by combining DGT and spectroscopic techniques N2 - Previous research shows that analytical methods based on Diffusive Gradients in Thin films (DGT) provide very good correlations to the amount of bioavailable nutrients and pollutants in the environmental samples. However, these DGT results do not identify which compound of the specific element has the high bioavailability. Using various spectroscopic techniques (infrared, XANES and NMR spectroscopy) to analyze the dried DGT binding layers after deployment could allow us to determine the specific elements or compounds. Nutrients such as phosphorus and nitrogen are often, together with other elements, present as molecules in the environment. These ions are detectable and distinguishable by infrared and NMR spectroscopy, respectively. In addition, XANES spectroscopy allows for the specification of nutrients and pollutants (e.g. chromium) on the DGT binding layer. Furthermore, microspectroscopic techniques make it also possible to analyze compounds on the DGT binding layer with a lateral resolution down to 5 µm2. Therefore, species of elements and compounds of e.g. a spatial soil segment can be mapped and analyzed, providing valuable insight to understand the dynamics of nutrients and pollutants in the environment. Here we will present the advantages and limitations of this novel combination of techniques. T2 - 6th Conference on Diffusive Gradients in Thin Films CY - Vienna, Austria DA - 17.09.2019 KW - Soil P species KW - DGT KW - Infrared spectroscopy PY - 2019 AN - OPUS4-49057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Sekine, R. A1 - Steckenmesser, D. A1 - Lombi, E. A1 - Herzel, Hannes A1 - Zuin, L. A1 - Wang, D. A1 - Felix, R. A1 - Adam, Christian T1 - Combining diffusive gradients in thin films (DGT) and spectroscopic techniques for the determination of phosphorus species in soils N2 - A wide range of methods are used to estimate the plant-availability of soil phosphorus (P). Published research has shown that the diffusive gradients in thin films (DGT) technique has a superior correlation to plant-available P in soils compared to standard chemical extraction tests. In order to identify the plantavailable soil P species, we combined DGT with infrared and P K- and L2,3-edge X-ray adsorption near edge structure (XANES) spectroscopy. This was achieved by spectroscopically investigating the dried binding layer of DGT devices after soil deployment. All three spectroscopic methods were able to distinguish between different kinds of phosphates (poly-, trimeta-, pyro- and orthophosphate) on the DGT binding layer. However, infrared spectroscopy was most sensitive to distinguish between different types of adsorbed inorganic and organic phosphates. Furthermore, intermediates of the time-resolved hydrolysis of trimetaphosphate in soil could be analyzed. KW - Phosphorus plant-availability KW - X-ray adsorption near-edge structure (XANES) spectroscopy KW - Infrared spectroscopy KW - Diffusive gradients in thin films (DGT) PY - 2019 DO - https://doi.org/10.1016/j.aca.2019.01.037 SN - 0003-2670 VL - 1057 SP - 80 EP - 87 PB - Elsevier AN - OPUS4-47471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weimann, Karin T1 - Gypsum plasterboard recycling N2 - The use of secondary building materials can meet the requirements of sustainability in several ways: the extended time availability of primary raw materials and, thereby, the protection of natural ressources as well as the conservation of landfill sites. Regarding the predicted decrease of gypsum supply in Germany, particularly the recycling of gypsum (calcium sulfate) is of growing importance. Currently, the gypsum demand is fulfilled (at least 60%) by gypsum as side product from coal-fired power plants (FGD Gypsum). Germany’s natural gypsum deposits fulfil the remaining gypsum demand. Due to national climate protection goals the gypsum supply from coal power plants will decrease significantly in the future. In addition, the content of sulfates in other secondary building materials, in particular in recycled concrete aggregates, should be minimized for quality reasons. Separated gypsum can be used in gypsum production if the high quality requirements for recycled gypsum are met. Accordingly, there have been significant advancements in the processing of gypsum residues in the last years. Since almost all processing steps in the recycling process are associated with environmental impacts, an evironmental evaluation of the use of recycled gypsum as a substitute in gypsum production has to be carefully conducted. The presentation focusses on the techniques for generating recycled gypsum from gypsum plaster boards, the related quality requirements and a comprehensive environmental evaluation of the complete process. T2 - MINEA Workshop: Recovery Potential of Construction and Demolition Waste CY - Brussels, Belgium DA - 21.03.2019 KW - Gypsum KW - CDW processing KW - Environmental evaluation PY - 2019 AN - OPUS4-48220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilke, Olaf T1 - Emission Testing for Indoor Products N2 - The chemical emissions from products are tested by means of emission test chambers under defined conditions (climate, loading, air change rate). The standard method for the determination of volatile organic compounds (VOC) is the sampling onto Tenax-tubes followed by thermal desorption (TDS) and gas chromatography-mass spectrometry (GC-MS) analysis. The EU-LCI list includes some very volatile organic compounds (VVOC) and some VOC for which there are limitations when using the standard method. For VVOC additional sampling is required using stronger absorbers like Carbotrap or multi-bed adsorption tubes. The analysis of VVOC also requires a different GC oven program and a different column for the separation. For the determination of formaldehyde and other low boiling aldehydes (e.g. acetaldehyde, acetone, propanal, propenal) DNPH-cartridges are used which are extracted with acetonitrile followed by liquid chromatography (HPLC-UV) analysis. The derivatisation of propenal and other unsaturated aldehydes (e.g. 2-butenal) with DNPH might lead to lower findings due to incomplete derivatization and forming of by-products. For a better quantification of acetic acid the use of ion chromatography (IC) is recommended because the analysis of acetic acid with the standard method (TDS) leads to lower findings due to break through during sampling. The use of ion chromatography for the analysis of organic acids requires a third sampling technique. The acids are adsorbed onto silica-gel and extracted with water. T2 - ISESISIAQ 2019 CY - Kaunas, Lituania DA - 18.08.2019 KW - Indoor Air Quality KW - Emission Testing KW - Indoor Products KW - VOC Emission KW - Construction Products PY - 2019 AN - OPUS4-49406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -