TY - JOUR A1 - Vogel, Christian A1 - Exner, Robert A1 - Adam, Christian T1 - Heavy metal removal from sewage sludge ash by thermochemical treatment with polyvinylchloride JF - Environmental science & technology N2 - Sewage sludge ash (SSA) is a prospective phosphorus source for the future production of recycling P-fertilizers. Due to its high heavy metals contents and the relatively low P plant-availability, SSA must be treated before agricultural utilisation. In this paper SSA was thermochemically treated with PVC in a bench-scale rotary furnace in order to remove heavy metals via the chloride pathway. PVC has a high Cl-content of 52–53% and a high heating value that can be beneficially used for the thermochemical process. Large amounts of waste PVC are already recovered in recycling processes, but there are still some fractions that would be available for the proposed thermochemical process, for example, the low quality near-infrared(NIR)-fraction from waste separation facilities. Heavy metals were effectively removed at temperatures in the range of 800–950°C via the gas phase by utilisation of PVC as Cl-donor. The resulting P plant-availability was comparable to SSA thermochemically treated with MgCl2 as Cl-donor if MgO was used as an additive (Mg-donor). A further increase of the plant availability of phosphorus was achieved by acid post-treatment of the thermochemically treated SSA. KW - Phosphorus recovery KW - Sewage sludge ash KW - Heavy metal removal KW - Polyvinylchloride (PVC) PY - 2013 DO - https://doi.org/10.1021/es300610e SN - 0013-936X SN - 1520-5851 VL - 47 IS - 1 SP - 563 EP - 567 PB - ACS Publ. CY - Washington, DC AN - OPUS4-27556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Krüger, Oliver A1 - Adam, Christian T1 - Thermochemical treatment of sewage sludge ash with sodium additives under reducing conditions analyzed by thermogravimetry JF - Journal of thermal analysis and calorimetry N2 - Phosphorus (P) for fertilizer use can be recovered from sewage sludge ash (SSA). To enhance the bioavailability of P and reduce the heavy metal content of SSA, it can be treated thermochemically with Na2CO3 or Na2SO4 at 950 °C in a rotary kiln using dry sewage sludge or lignite as reducing agent. These processes were investigated by thermogravimetry/differential thermal analysis coupled with gas analysis. Reducing conditions in this experimental setup were provided by 2 % hydrogen in the Ar carrier gas. During SSA + Na2CO3 treatment CO2, CO and water were detected in the off-gas. During SSA + Na2SO4 treatment SO2, some CO2 and water were detected. Heavy metal removal was more efficient for SSA + Na2CO3 compared to the sulfate variant. A SSA + Na2SO4 + lignite variant which also formed CO shifted the heavy metal removal to the results obtained with Na2CO3 which was obviously due to the additional reduction potential. However, Zn evaporation was not achieved with the Na2SO4 variants which were most probably due to immobilization as ZnS. KW - Phosphorus recovery KW - Thermochemical treatment KW - Sewage sludge ash KW - Reducing conditions KW - Heavy metal evaporation KW - FT-IR gas analysis PY - 2016 DO - https://doi.org/10.1007/s10973-015-5016-z SN - 1388-6150 SN - 1418-2874 SN - 0368-4466 SN - 1572-8943 VL - 123 IS - 2 SP - 1045 EP - 1051 PB - Springer CY - Dordrecht AN - OPUS4-34556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Schäfers, F. A1 - Adam, Christian T1 - Chemical state of chromium, sulfur, and iron in sewage sludge ash based phosphorus fertilizers JF - ACS sustainable chemistry & engineering N2 - As an essential element of all life forms, phosphorus (P) is vital to the fertilizer industry. With decreasing quantity and quality of phosphate rock resources, recycling P-fertilizers from wastewater is of increasing interest. The P-fertilizer products of a recently developed thermochemical process for P recovery from sewage sludge ash (SSA) were investigated by chromium, sulfur, and iron K-edge X-ray near-edge structure (XANES) spectroscopy. This paper focuses the formation and prevention of toxic chromium(VI) and toxic sulfides during the thermochemical processes. Reducing conditions prevent the oxidation of chromium(III) in the SSA to toxic chromium(VI). Sulfides formed under the reducing conditions are nontoxic iron sulfides. Hematite (Fe2O3) present in the SSA is reduced to magnetite (Fe3O4). A gentle post-treatment at 400 °C under oxidizing conditions converts the iron sulfides into plant-available iron sulfates. This oxidative post-treatment does not form undesired chromium(VI) compounds. KW - X-ray absorption near-edge structure (XANES) spectroscopy KW - Phosphorus recovery KW - Sewage sludge ash KW - Chromium KW - Sulfur KW - Iron PY - 2015 DO - https://doi.org/10.1021/acssuschemeng.5b00678 SN - 2168-0485 VL - 3 IS - 10 SP - 2376 EP - 2380 PB - ACS Publ. CY - Washington, DC AN - OPUS4-34166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Krüger, Oliver A1 - Herzel, Hannes A1 - Amidani, L. A1 - Adam, Christian T1 - Chemical state of mercury and selenium in sewage sludge ash based P-fertilizers JF - Journal of Hazardous Materials N2 - Phosphorus-fertilizers from secondary resources such as sewage sludge ash (SSA) will become more important in the future as they could substitute conventional fertilizers based on the nonrenewable resource phosphate rock. Thermochemical approaches were developed which remove heavy metals from SSA prior to its fertilizer application on farmlands. We analyzed the chemical state of mercury and selenium in SSA before and after thermochemical treatment under different conditions for P-fertilizer production by X-ray absorption near edge structure (XANES) spectroscopy. In some incineration plants the mercury loaded carbon adsorber from off-gas cleaning was collected together with the SSA for waste disposal. SSAs from those plants contained mercury mainly bound to carbon/organic material. The other SSAs contained inorganic mercury compounds which are most probably stabilized in the SSA matrix and were thus not evaporated during incineration. During thermochemical treatment, carbon-bound mercury was removed quantitatively. In contrast, a certain immobile fraction of inorganic mercury compounds remained in thermochemically treated SSA, which were not clearly identified. HgSe might be one of the inorganic compounds, which is supported by results of Se K-edge XANES spectroscopy. Furthermore, the chemical state of selenium in the SSAs was very sensitive to the conditions of the thermochemical treatment. KW - X-ray absorption near edge structure (XANES) spectroscopy KW - Phosphorus recovery KW - Sewage sludge ash KW - Mercury KW - Selenium KW - Mercury selenide (HgSe) PY - 2016 UR - http://dx.doi.org/10.1016/j.jhazmat.2016.03.079 DO - https://doi.org/10.1016/j.jhazmat.2016.03.079 VL - 313 SP - 179 EP - 184 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-35718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR 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 - Effects of a nitrification inhibitor on nitrogen species in the soil and the yield and phosphorus uptake of maize JF - Science of the total environment 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 low plant availability. Specific co-fertilization with ammoniumcan enhance P plant availability in soils amended with these P fertilizers, and thus the yield of plants. To investigate this effect, we performed a pot experiment with maize in slightly acidic soil (pH 6.9) with one water-soluble (triple superphosphate [TSP]) and two water-insoluble (sewage sludge-based and hyperphosphate [Hyp]) P fertilizers and anammoniumsulfate nitrate with or without a nitrification inhibitor (NI). The dry matter yield of maize was significantly increased by the NI with the Hyp (from 14.7 to 21.5 g/pot) and TSP (from 40.0 to 45.4 g/pot) treatments. Furthermore, P uptake was slightly increased in all three P treatments with the NI, but not significantly. Olsen-P extraction and P K-edge micro-X-ray absorption near-edge structure (XANES) spectroscopy showed that apatite-P of the water insoluble P fertilizers mobilized during the plant growth period. In addition, novel nitrogen (N) K-edge micro-XANES spectroscopy and the Mogilevkina method showed that the application of an NI increased the fixation of ammonium in detectable hot spots in the soil. Thus, the delay in the nitrification process by the NI and the possible slow-release of temporarily fixed ammoniumin the soil resulted in a high amount of plant available Ammonium in the soil solution. This development probably decreases the rhizosphere pH due to release of H+ by plants during ammoniumuptake, whichmobilizes phosphorus in the amended soil and increases the dry matter yield of maize. This is especially important for water-insoluble apatite-based P fertilizers (conventional and recycled), which tend to have poor plant availability. KW - Fertilzer KW - Phosphorus recovery KW - Ammonium KW - Nitrification inhibitor KW - XANES spectroscopy KW - Diffusive gradients in thin films (DGT) PY - 2020 DO - https://doi.org/10.1016/j.scitotenv.2020.136895 SN - 1879-1026 VL - 715 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-50477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Adam, Christian A1 - Kugler, Stefan A1 - Herzel, Hannes T1 - Phosphorus recovery from waste streams for fertilizer production N2 - Phosphorus (P) plays an essential role in the global food security. However, the global P reservoirs have a statistic lifetime of about 385 years only. Due to the scarcity of P and the increasing world population an efficient and sustainable recycling management is required. A few biogenic waste materials are high in P contents such as sewage sludge and meat and bone meal. Thus, they are suitable for P recycling and fertilizer production. But besides the high P content sewage sludge is often highly contaminated with organic pollutants and toxic heavy metals which have to be eliminated before agricultural field application. In this presentation we show the potential of sewage sludge as secondary resource for fertilizers. This includes our developments in thermochemical processes for the production of novel P-fertilizers from recycled materials. Furthermore, for these novel P-fertilizers common extraction tests to determine the plant-available P are often unusable. Therefore, we successfully applied the Diffusive gradients in thin-films (DGT) techniques to analyse the plant-availability of P-fertilizers from recycled materials. T2 - Eingeladener Vortrag an der University of South Australia CY - Mawson Lakes, Australia DA - 22.11.2018 KW - Phosphorus recovery KW - Sewage sludge KW - Diffusive Gradients in thin films (DGT) PY - 2018 AN - OPUS4-46764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -