Sulfur (S) is an abundant and redox-active element in urban wastewater systems plays a critical role both the sludge treatment processes. This study comparatively characterized transformation of S several closely associated metals (Cu, Zn, Fe) during pyrolysis (250 to 750 °C) hydrothermal carbonization (HTC, 150 275 treatments sewage sludge. S, Fe, Cu K-edge X-ray absorption spectroscopy was ap...

The uses of biochar as soil fertilizer can offset global warming and reduce dependence on limited mineral resources in the future circular economy, yet may contain contaminants that ultimately enter food chain. In particular, persistent free radicals are emerging previously detected but underlying mechanisms radical formation not established. Here we studied generation during hydrothermal carbo...