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Retrospective analysis of cyclic volatile methylsiloxanes in archived German fish samples covering a period of two decades

Radermacher, Georg; Rüdel, Heinz; Wesch, Charlotte; Böhnhardt, Anna; Koschorreck, Jan Science of The Total Environment 706 (2020), März, 136011; online 9. Dezember 2019 Cyclic volatile methylsiloxanes (cVMS) are widely applied chemicals used as intermediates in the production of silicon polymers or as ingredients in personal care products. cVMS are under scrutiny due to their environmental properties and their potential for long-range atmospheric transport, persistence and food web magnification. In 2018, the cVMS octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were identified as Substances of Very High Concern (SVHC) under the European REACH regulation. To obtain current data on the presence of cVMS in German waters, the spatial and temporal occurrence of D4, D5 and D6 in fillets of bream from major rivers archived in the German Environmental Specimen Bank (ESB) was analyzed with a GC-ICP-MS/MS coupling method. The spatial comparison of 17 sites for the year 2017 revealed that highest cVMS burdens occurred in samples from the Saar river (near to the French/German border). cVMS levels in fish from a lake in northern Germany did not exceed the limits of detection. For selected sites, time series covering the period from 1995 to 2017 were investigated. In most years D5 concentrations in fish were clearly higher than the observed D4 and D6 concentrations. Overall maximum D4 and D5 concentrations (about 320 and 7600 ng g−1 wet weight, respectively) were found at one Saar site in 2009. In three of five analyzed time series D5 concentrations peaked 2007–2011. In recent years, cVMS levels in fish decreased at almost all sites. To allow an assessment of the relevance of the detected cVMS fish concentrations these were compared to environmental quality standards (EQS) for D4 and D5 which were recently enacted in the context of the Swedish implementation of the European Water Framework Directive (WFD). The D5 EQS in fish was exceeded at four sites in several years in the investigated period and in the Saar even till 2017. doi: 10.1016/j.scitotenv.2019.136011

Markt für Mangan

technologyComment of manganese production (RER): The metal is won by electrolysis (25%) and electrothermic processes (75%). ELECTROLYSIS OF AQUEOUS MANGANESE SALTS The production of manganese metal by the electrolysis of aqueous manganese salts requires at first a milling of the manganese ore. Milling increases the active surface and ensures sufficient reactivity in both the reduction and the subsequent leaching steps. After milling the manganese ore is fed to a rotary kiln where the reduction and calcination takes place. This process is carried out at about 850 - 1000 ºC in a reducing atmosphere. As a reducing agent, several carbon sources can be used e.g. anthracite, coal, charcoal and hydrocarbon oil or natural gas. The cal-cined ore needs to be cooled below 100 ºC to avoid a further re-oxidation. The subsequent leaching process is carried out with recycled electrolyte, mainly sulphuric acid. After leaching and filtration the iron content is removed from the solution by oxidative precipitation and the nickel and cobalt are removed by sulphide precipitation. The purified electrolyte is then treated with SO2 in order to ensure plating of γ-Mn during electrolysis. Electrolysis is carried out in diaphragm cells. The cathode is normally made of stainless steel or titanium. For the anode lead-calcium or lead-silver alloy can be used. After an appropriate reaction time the cathodes are removed from the electrolysis bath. The manganese that is deposited on the cathode starter-sheet is stripped off mechanically and then washed and dried. The metal is crushed to produce metal flakes or powder or granulated, depending on the end use. ELECTROTHERMAL DECOMPOSITION OF MANGANESE ORES The electrothermal process is the second important process to produce manganese metal in an industrial scale. The electrothermal process takes place as a multistage process. In the first stage manganese ore is smelted with only a small amount of reductant in order to reduce mostly the iron oxide. This produces a low-grade ferro-manganese and a slag that is rich in Mn-oxide. The slag is then smelted in the second stage with silicon to produce silicomanganese. The molten silicomanganese can be treated with liquid slag from the fist stage to obtain relatively pure manganese metal. For the last step a ladle or shaking ladle can be used. The manganese metal produced by the electrothermal process contains up to 98% of Mn. Overall emissions and waste: Emissions to air consist of dust and fume emissions from smelting, hard metal and carbide production; Other emissions to air are ammonia (NH3), acid fume (HCl), hydrogen fluoride (HF), VOC and heavy metals. Effluents are composed of overflow water from wet scrubbing systems, wastewater from slag and metal granulation, and blow down from cooling water cycles. Waste includes dust, fume, sludge and slag. References: Wellbeloved D. B., Craven P. M. and Waudby J. W. (1997) Manganese and Manganese Alloys. In: Ullmann's encyclopedia of industrial chemistry (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. IPPC (2001) Integrated Pollution Prevention and Control (IPPC); Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European Commission. Retrieved from http://www.jrc.es/pub/english.cgi/ 0/733169 technologyComment of manganese production (RoW): The metal is won by electrolysis (assumption: 25%) and electrothermic processes (assumption: 75%). No detailed information available, mainly based on rough estimates. technologyComment of treatment of non-Fe-Co-metals, from used Li-ion battery, hydrometallurgical processing (GLO): The technique SX-EW is used mainly for oxide ores and supergene sulphide ores (i.e. ores not containing iron). It is assumed to be used for the treatment of the non-Fe-Co-metals fraction. The process includes a leaching stage followed by cementation or electro-winning. A general description of the process steps is given below. In the dump leaching step, copper is recovered from large quantities (millions of tonnes) of strip oxide ores with a very low grade. Dilute sulphuric acid is trickled through the material. Once the process starts it continues naturally if water and air are circulated through the heap. The time required is typically measured in years. Sulphur dioxide is emitted during such operations. Soluble copper is then recovered from drainage tunnels and ponds. Copper recovery rates vary from 30% to 70%. Cconsiderable amounts of sulphuric acid and leaching agents emit into water and air. No figures are currently available on the dimension of such emissions. After the solvent-solvent extraction, considerable amounts of leaching residues remain, which consist of undissolved minerals and the remainders of leaching chemicals. In the solution cleaning step occur precipitation of impurities and filtration or selective enrichment of copper by solvent extraction or ion exchange. The solvent extraction process comprises two steps: selective extraction of copper from an aqueous leach solution into an organic phase (extraction circuit) and the re-extraction or stripping of the copper into dilute sulphuric acid to give a solution suitable for electro winning (stripping circuit). In the separation step occurs precipitation of copper metal or copper compounds such as Cu2O, CuS, CuCl, CuI, CuCN, or CuSO4 • 5 H2O (crystallisation) Waste: Like in the pyrometallurgical step, considerable quantities of solid residuals are generated, which are mostly recycled within the process or sent to other specialists to recover any precious metals. Final residues generally comprise hydroxide filter cakes (iron hydroxide, 60% water, cat I industrial waste).

Best Available Techniques (BAT) reference document for the non-ferrous metals industries

The BAT reference document (BREF) entitled 'Non-Ferrous Metals Industries' forms part of a series presenting the results of an exchange of information between EU Member States, the industries concerned, non-governmental organisations promoting environmental protection, and the Commission, to draw up, review and, where necessary, update BAT reference documents as required by Article 13(1) of the Directive 2010/75/EU on industrial emissions. This document is published by the European Commission pursuant to Article 13(6) of the Directive. This BREF for 'Non-Ferrous Metals Industries' concerns the activities specified in Sections 2 and 6.8 of Annex I to Directive 2010/75/EU, namely: - 2.1: Metal ore (including sulphide ore) roasting or sintering; - 2.5: Processing of non-ferrous metals: (a) production of non-ferrous crude metals from ore, concentrates or secondary raw materials by metallurgical, chemical or electrolytic processes; (b) melting, including the alloyage, of non-ferrous metals, including recovered products and operation of non-ferrous metal foundries, with a melting capacity exceeding 4 tonnes per day for lead and cadmium or 20 tonnes per day for all other metals; - 6.8: Production of carbon (hard-burnt coal) or electrographite by means of incineration or graphitisation. This document also covers: - the production of zinc oxide from fumes during the production of other metals; - the production of nickel compounds from liquors during the production of a metal; - the production of silicon-calcium (CaSi) and silicon (Si) in the same furnace as the production of ferro-silicon; - the production of aluminium oxide from bauxite prior to the production of primary aluminium, where this is an integral part of the production of the metal; - the recycling of aluminium salt slag. Important issues for the implementation of Directive 2010/75/EU in the non-ferrous metals industries are the emissions to air of dust, metals, organic compounds (which can result in the formation of PCDD/F) and sulphur dioxide; diffuse air emissions; emissions to water of metals (e.g. Hg, Cd, Cu, Pb, Zn); resource efficiency; and the prevention of emissions to soil and groundwater. This BREF contains 12 chapters. Chapters 1 and 2 provide general information on the non-ferrous metals industry and on the common industrial processes and techniques used within the whole sector. Chapters 3, 4, 5, 6, 7, 8, 9 and 10 correspond to the following specific production sectors: copper, aluminium, lead and/or tin, zinc and/or cadmium, precious metals, ferro-alloys, nickel and/or cobalt, and carbon and graphite. For each specific production sector, these eight chapters provide information and data concerning the applied processes and techniques; the environmental performance of installations in terms of current emissions, consumption of raw materials, water and energy, and generation of waste; the techniques to prevent or, where this is not practicable, to reduce the environmental impact of operating installations in these sectors that were considered in determining the BAT; and the emerging techniques as defined in Article 3(14) of the Directive. Chapter 11 presents the BAT conclusions as defined in Article 3(12) of the Directive. Chapter 12 is dedicated to concluding remarks and recommendations for future work. Quelle: BAT-Merkblatt JRC 107041

Markt für Silizium, Elektronikqualität

technologyComment of silicon production, electronics grade (DE, RoW): In practice, EG-silicon is a product from complex chemical production plants. The conventional route for production of EG-silicon comprises three process steps: 1) the MG-silicon is converted into a gas, either trichlorosilane (SiHCl3) or silane (SiH4), 2) this gas is purified by means of distillation, 3) silicon in solid form is deposited in a Siemens reactor. Reference: Jungbluth N., Stucki M, and Frischknecht R. (2009) Photovoltaics. In Dones, R. (Ed.) et al., Sachbilanzen von Energiesystemen: Grundlagen für den ökologischen Vergleich von Energiesystemen und den Einbezug von Energiesystemen in Ökobilanzen für die Schweiz. ecoinvent report No. 6-XII, Swiss Centre for Life Cycle Inventories, Dübendorf, CH, 2009.

PV power supply for ground water level measurement

Das Projekt "PV power supply for ground water level measurement" wird vom Umweltbundesamt gefördert und von AEG AG durchgeführt. Objective: To demonstrate the performance and reliability of three small (307 Wp), stand-alone pv systems as power supplies for the measurement of ground water level at 3 sites near Hamburg. A further aim was to determine whether data transfer via radio is a reliable possibility. General Information: In this project PV arrays are used to power three meters for measuring the ground water level in wells in the Haseldorfer Marsch area near Hamburg. The Hamburg Waterworks authority operate about 150 ground water level meters in this area which monitor variations in the ground water level, so that pumping at the wells can be regulated in accordance with the availability of ground water. Formerly the meters were read and the data collected manually during a fortnightly inspection trip. This method is costly and may overlook short term variations in the water level. The pv powered meters in this project have radio transceivers which, when activated by a signal from a central station every 30 minutes, transmit water level data to the central station for automatic decoding, collection and storage. Each of the three groundwater level meters is powered by a 307 Wp array consisting of 16 AEG modules of type PQ10/20 of polycrystalline silicon. The modules are connected through a charge controller (type BCR 12 Sh300) to a 12V, 100 Ah battery, which allows operation on 10 consecutive days with no sun. The charge controller prevents overcharging and excessive discharging of the battery. Savings are made by removing the need for visits by maintenance staff to manually read the meters. Monitoring has been carried out at each of the three water level meters in accordance with the JRC Ispra monitoring guidelines. Achievements: Since the commissioning the pv power supply operated without any failure. However it was impossible to get reliable data transmission via radio; the distances between the central unit and the measurement sites were 200 m, 5 km and 20 km. In 1987 the whole data logger system was sent to the manufacturer for improvements, without success. PV has proven to be a reliable, economical and ecological energy source for this type of application. The data logger and the transmittance of the data by radio would have to be revised completely. The average annual energy production of one system is 173 kWh. Energy cost is calculated to be 11.5 Ecu/kWh (3.5 Ecu/kWh for a replication).

Nutzung der Passivierung in M/S-A-Si:H-Solarzellen

Das Projekt "Nutzung der Passivierung in M/S-A-Si:H-Solarzellen" wird vom Umweltbundesamt gefördert und von Universität Konstanz, Fakultät für Physik durchgeführt. General Information: in crystalline silicon it is well known, that a thin tunneling oxide at the interface between the absorbing semiconductor and the barrier forming metal leads to an increase of the open circuit voltage and thus to the efficiency of solar cells. Our study deals with the passivation of amorphous silicon. The influence of the passivated a-Si:H surface is examined by a MIS (metal-insulator-semiconductor) solar cell. In order to reduce the activation energy of the oxide forming process, we developed a plasma reactor powered by a 2.45 GHZ microwave generator. This multiple gas system allows to study different plasma reactions. After a water-vapour plasma treatment we observed a considerable increase of the open circuit voltage from 610 MV up to 900 MV with pt and up to 870 MV with IR as barrier metal. The MIS solar cells proved to be very stable. The cell with 900 MV open circuit voltage stabilized after a year around 870 MV. Because of the high reflection from the barrier metal and the A-Si:H surface one gets low photocurrents. By coating the cell with a zro2 antireflective layer the photocurrent could be improved from 7 ma/cm2 to about 11 ma/cm2 for polished samples. A further improvement of the photocurrent could be achieved by roughening the stainless steel substrate. Astonishingly the A-Si:H on the sand-blasted substrate does not exhibit destructive influence on the MIS-interface. The roughening procedure is still not optimized, because we only used a 50 micrometer grain size for sand-blasting. Our MIS solar cells with A-Si:H as base material and the plasma passivation exhibit efficiencies of about 5 per cent. Achievements: A microwave plasma technique has been used to oxidize hydrogenated amorphous silicon at low temperatures. By a water vapour treatment of the surface, very large open circuit voltages, up to 905 MV, have been obtained in metal insulator semiconductor (MIS) type solar cell structures. The grown oxides were analysed by auger electron spectroscopy (AES), ellipsometry and other methods. The plasma oxide thickness lies in the range 11-17 angstroms. Although dry oxidation led to similar oxide thicknesses, wet oxidation provided better results. As expected, the plasma oxide reduces the MIS forward and reverse dark current and leads to an increase in open circuit voltage and photocurrent. The photocurrent enhancement is due to an increased blue response of the cell. Significant differences exist between native and plasma oxides. This has been shown in an impressive way in surface wetting experiments with a water droplet on oxidized surfaces. The open circuit voltage of cells stored for 3 years remained nearly constant, which indicates a good chemical stability of the MIS cell.

Towards 20 percent mc-Si industrial solar cell efficiency

Das Projekt "Towards 20 percent mc-Si industrial solar cell efficiency" wird vom Umweltbundesamt gefördert und von Universität Konstanz, Lehrstuhl für Angewandte Festkörperphysik durchgeführt. TOPSICLE is an R und D project to develop a low-cost industrial process for super high-efficiency multicrystalline silicon (mc-Si) cells and modules. This project will result in an efficiency of 20 percent for a 4cm2mc-Si cell, 19 percent for a 156 cm2 mc-Si cell and 18 percent for a full size 36 cell module. The peak power of that module will be 101 Wat.a road map will be made to realise cost effective 20 percent mc-Si PV modules on an industrial scale. To reach these goals the consortium will develop processes for: 1) manufacturing high-quaity cast ingots; 2) slicing high-quality thin mc-Si wafers; 3) manufacturing super high-efficiency mc-Si solar cells and; 4) fabricating PV modules with novel designs and using advanced techniques. TOPSICLE will strongly contribute to the White Paper targets (3GWp installed in2010, kleiner 2.5/Wp, 3Mtn/yr CO 2 reduction) and will increase Europe's competitive position considerably. The results of TOPSICLE will reduce the energy-pay-back time of themc-Si based PV systems to 2-3 years.

Food to Food-Recycling von PET mittels Prozess-Laser-Fluoreszenz und Prozess-Raman-Spektroskopie

Das Projekt "Food to Food-Recycling von PET mittels Prozess-Laser-Fluoreszenz und Prozess-Raman-Spektroskopie" wird vom Umweltbundesamt gefördert und von UNISENSOR Sensorsysteme GmbH durchgeführt. Zielsetzung und Anlass des Vorhabens: Der zunehmende Einsatz von PET-Kunststoffen für Getränkeflaschen und Lebensmittelbehälter bei gleichzeitig starkem Rückgang der Verwendung von Glasflaschen hat zu einer enormen Steigerung des Verbrauchs von Rohöl geführt. Eine Mehrfachverwendung von Kunststoffen im Lebensmittelbereich durch Recyclingprozesse ist daher unvermeidbar. Das Vorhaben umfasst daher die Entwicklung eines Mess- und Sortiersystems zur Erkennung und Ausscheidung von Fremdkunststoffen z.B. PVC, Nylon, etc., Fremdmaterialien z.B. Silikon, Holz, Leimreste, Metall, Papier, Glas etc., Kontaminationen z.B. Benzin, Diesel, Altöl etc. sowie fremdfarbiges PET. Fazit: Für das Food-to-Food-Recycling von PET befindet sich das System in der Phase der Serienproduktion und der internationalen Vermarktung. Wegen des zur Zeit niedrigen Ölpreises wird diese Phase längere Zeit in Anspruch nehmen als ursprünglich erwartet. Um diesen Effekt weitgehend zu kompensieren, laufen bereits intensive Anstrengungen um das System in weiteren Märkten, z.B. in der Nahrungsmittelbranche, einzusetzen.

Ultra compact high flux GaAs cell photovoltaic concentrator

Das Projekt "Ultra compact high flux GaAs cell photovoltaic concentrator" wird vom Umweltbundesamt gefördert und von Telefunken electronic durchgeführt. General Information/Project Objectives: To design and build a photovoltaic concentrator based on a new optical design and a recently developed GaAs cell. The device will be capable of operation at 1000 suns with an acceptance angle of + / - 1.5 degrees, a global efficiency of 20-22 per cent (at Tcell=25 degrees), a cell to ambient temperature deop not greater than 40 degrees, and a total concentrator thickness not greater than 0.5 its aperture diameter. Because of several reasons, this aperture diameter will be in the range of 4-7 cm so the cell size is such that its manufacturing, bonding and encapsulation technologies become close t that of common opto-electronics devices and so the cost can be reduced up to the range of 0.1 ECU/KWh for a Southern Europe installation (on a large production basis). The cost reduction is partially based on using upto-electronics industry expertise and equipment. The last objective is to evaluate this cost. Technical Approach: The optical concentrator is of RXI type, which is unique providing large acceptance angles for high concentration devices. The concentrator will be turned on PMMA with diamond-tipped tools and will also be manufactured by injection molding (also using high accuracy tools for the molds). Mirroring of concentrator surfaces will be achieved by evaporation of solver. Encapsulation of the cell and filling of the region with high irradiance levels will be done by potting clear silicone. Two cell technologies will be used: Low Temperature Liquid Phase Epitaxy n GaAs and MOCVD also on GaAs. The first one is a recently developed technology which provides high quality material and allows the growing of structures as complex as the one to be grown here: a highly doped GaAs cap contact layer, an ultra-thin wide gap window, a thin photoactive p-GaAs, a photoactive n-GaAs achieved with a less complex structure. Optical efficiency, acceptance angle and cell efficiency will be measured at indoors facilities using solar simulators and conventional optical and electronic equipment. Photovoltaic concentrator efficiency, angular response and operating temperature will be measured at outdoors facilities. Expected Achievements and Exploitation: The main expected achievement is to prove the feasibility of the concept, i.e. to prove that significant cost reduction of photovoltaic energy may derive from the gathering of the following items: 1) GaAs cells working efficiently under high irradiance, 2) new concentrator designs combining large acceptance angles with high concentration factions and 3) the technology and expertise of the opto-electronic industry. Experience on photovoltaic cells and concentrators working under high irradiance should also result from the project, as well as the experience on encapsulation and bonding for such applications. ... Prime Contractor: Universidad Politecnica de Madrid, Instituto de Energia Solar; Madrid; Spain.

Large grained, low stress multi-crystalline silicon thin film solar cells on glass by a novel combined diode laser and solid phase crystallization process (HIGH-EF)

Das Projekt "Large grained, low stress multi-crystalline silicon thin film solar cells on glass by a novel combined diode laser and solid phase crystallization process (HIGH-EF)" wird vom Umweltbundesamt gefördert und von Institut für Photonische Technologien e.V. durchgeführt. Objective: HIGH-EF will provide the silicon thin film photovoltaic (PV) industry with a unique process allowing for high solar cell efficiencies (potential for greater than 10 percent) by large, low defective grains and low stress levels in the material at competitive production costs. This process is based on a combination of melt-mediated crystallization of an amorphous silicon (a-Si) seed layer (less than 500 nm thickness) and epitaxial thickening (to greater than 2 mym) of the seed layer by a solid phase crystallization (SPC) process. Melting the a-Si layer and solidifying large grains (about 100 mym) will be obtained by scanning a beam of a diode laser array. Epitaxial thickening of the large grained seed layer (including a pn-junction) is realized by deposition of doped a-Si atop the seed layer and a subsequent SPC process by way of a furnace anneal. Such a combined laser-SPC process represents a major break-through in silicon thin film photovoltaics on glass as it will substantially enhance the grain size and reduce the defect density and stress levels of multi-crystalline thin layers on glass compared e.g. to standard SPC processes on glass, which provide grains less than 10 mym in diameter with a high density of internal extended defects, which all hamper good solar cell efficiencies. It is, however, essential for the industrial laser-SPC implementation that such a process will not be more expensive than the established pure SPC process. A low cost laser processing will be developed in HIGH-EF using highly efficient laser diodes, combined to form a line focus that allows the crystallization of an entire module (e.g. 1.4 m x 1 m in the production line or 30 cm x 39 cm in the research line) within a single scan. Specific attention has been given to identify each competence needed for the success of the project and to identify the relevant partners forming a balanced, multi-disciplinary consortium gathering 7 organizations from 4 different member states with 1 associated country.

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