TY - JOUR A1 - Steckenmesser, D. A1 - Vogel, Christian A1 - Adam, Christian A1 - Steffens, D. T1 - Effect of various types of thermochemical processing of sewage sludges on phosphorus speciation, solubility, and fertilization performance N2 - Sewage sludge has one of the highest phosphorus (P) recovery potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to closing the P-cycle. Recently, various thermal processes for P-recovery have been developed, but there is still a demand for information on the effect of different process parameters (e.g. additives and temperature) on P-speciation and especially on the fertilization performance. In the present study, two common methods (low-temperature conversion at 400–500 °C and thermochemical treatment at 950 °C) were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation (Chem-P) and enhanced biological phosphorus removal (Bio-P). The results of P-fractionation, X-ray diffraction analysis, and pot experiments with maize showed that Bio-P sludges attain high P-plant-availability after treatment at low temperatures (400 °C). In contrast, Chem-P sludges can adequately be treated at higher temperatures under reductive conditions with sodium additives to form highly bioavailable calcium-sodium-phosphate. Additionally, also highly heavy-metal contaminated sludges can be thermochemically treated at high temperatures to achieve the legal requirements for fertilizers. KW - P-recovery KW - Low-temperature-conversion KW - Thermochemical treatment KW - P-fractionation KW - P-plant-availability KW - Sewage sludge PY - 2017 U6 - https://doi.org/10.1016/j.wasman.2017.02.019 SN - 0956-053X VL - 62 SP - 194 EP - 203 AN - OPUS4-39907 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 - Steffens, D. A1 - Adam, Christian T1 - Phosphorus availability of sewage sludge-based fertilizers determined by the diffusive gradients in thin films (DGT) technique N2 - The plant-availability of phosphorus (P) in fertilizers and soil can strongly influence the yield of agricultural crops. However, there are no methods to efficiently and satisfactorily analyze the plant-availability of P in sewage sludge-based P fertilizers except by undertaking time-consuming and complex pot or field experiments. We employed the diffusive gradients in thin films (DGT) technique to quantify the plant P availability of various types of P fertilizers with a novel focus on sewage sludge-based P fertilizers. Mixtures of fertilizer and soil were incubated for 3 weeks at 60% water holding capacity. DGT devices were deployed at the beginning of the incubation and again after 1, 2, and 3 weeks. Two weeks of incubation were sufficient for the formation of plant-available P in the fertilizer/soil mixtures. In a pot experiment, the DGT technique predicted maize (Zea mays L.) biomass yield and P uptake significantly more accurately than standard chemical extraction tests for P fertilizers (e.g., water, citric acid, and neutral ammonium citrate). Therefore, the DGT technique can be recommended as a reliable and robust method to screen the performance of different types of sewage sludge-based P fertilizers for maize cultivation minimizing the need for time-consuming and costly pot or field experiments. KW - Soil testing KW - Chemical extraction tests KW - Phosphate recovery KW - Plant growth experiments KW - Recycling PY - 2017 U6 - https://doi.org/10.1002/jpln.201600531 VL - 180 IS - 5 SP - 594 EP - 601 PB - Wiley VCH Verlag AN - OPUS4-42413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steckenmesser, D. A1 - Vogel, Christian A1 - Adam, Christian A1 - Steffens, D. T1 - Effect of various types of thermochemical processing of sewage sludges on phosphorus speciation, solubility, and fertilization performance N2 - Sewage sludge has one of the highest phosphorus (P) recovery potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to closing the P-cycle. Recently, various thermal processes for P-recovery have been developed, but there is still a demand for information on the effect of different process parameters (e.g. additives and temperature) on P-speciation and especially on the fertilization performance. In the present study, two common methods (low-temperature conversion at 400–500° C and thermochemical treatment at 950° C) were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation (Chem-P) and enhanced biological phosphorus removal (Bio-P). The results of P-fractionation, X-ray diffraction analysis, and pot experiments with maize showed that Bio-P sludges attain high P-plant-availability after treatment at low temperatures (400° C). In contrast, Chem-P sludges can adequately be treated at higher temperatures under reductive conditions with sodium additives to form highly bioavailable calcium-sodium-phosphate. Additionally, also highly heavy-metal contaminated sludges can be thermochemically treated at high temperatures to achieve the legal requirements for fertilizers. KW - P-recovery KW - Low-temperature-conversion KW - Thermochemical treatment KW - P-fractionation KW - P-plant-availability KW - Sewage sludge PY - 2017 U6 - https://doi.org/10.1016/j.wasman.2017.02.019 SN - 0956-053X VL - 62 SP - 194 EP - 203 PB - Elsevier CY - Amsterdam AN - OPUS4-41646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -