Relevance of Pyrolysis Products Derived from Sewage Sludge for Soil Applications

The recovery of sludge produced in the wastewater treatment process WWTPs is often limited by high content toxic forms contaminants both an inorganic and organic nature. One options for effective world’s ever-increasing quantities sewage pyrolysis process. Thermochemical conversion emerging as a promising method treating these heterogeneous highly complex wastes with increasing research work. Pyrolysis-treated (PM) prepared at 603–615 °C was characterized pH, EC, CHN-S analysis; total bioavailable concentrations P heavy metals (Cd, Cu, Fe Zn); fractionation bound material determination presence polycyclic aromatic hydrocarbons (PAHs). studied subjected to ecotoxicological tests (Daphnia pulex L.) cultivation (Lactuca sativa L.). Elemental analysis revealed PM: (137,600 mg/kg), Zn (2602 Cu (582 Cr (107 Pb (87 Ni (67 As (<1 Hg (<2 mg/kg) Cd mg/kg). highest values extractability investigated from PM were found cases (HCl) (Mehlich 3), not exceeding 500 mg/kg. BCR sequential extraction showed major predominantly residual fraction (F4) reducible (F2) PM. results metal bioavailability suggest that addition does negatively affect growth lettuce biomass contents plant tissues. Based on obtained, municipal seems be innovative soil additive potential alternative conventional fertilizers.