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 T2 - 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. PB - Springer CY - Dordrecht KW - Phosphorus recovery KW - Thermochemical treatment KW - Sewage sludge ash KW - Reducing conditions KW - Heavy metal evaporation KW - FT-IR gas analysis PY - 2016 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/34556 AN - OPUS4-34556 SN - 1388-6150 SN - 1418-2874 SN - 0368-4466 SN - 1572-8943 VL - 123 IS - 2 SP - 1045 EP - 1051 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany