Cleanup of sewage sludge spiked with Cd, Cu, and Zn: Sludge quality and distribution of metals in the “soil-plant-water” system

Abstract Corn was grown under greenhouse conditions in the presence of uncleaned versus cleaned municipal sewage sludge to assess effectiveness a chemical leaching process that uses an inorganic acid and strong oxidants clean biosolids (i.e., remove metals without reducing their agronomic potential). Specifically, our study analyzed physicochemical from Montreal (MSL) wastewater treatment plant (WTP) biological Becancour (BSL) WTP. Both were spiked with individual (dry weight basis): Cd (100 mg kg-1), Cu (3000 mg kg−1), Zn (5000 mg kg−1), or mixture. MSL biosolid enrichment led solubilization added removed 84–88% Cd, 78–79% Cu, 79–81% Zn. Similarly, BSL resulted removal 86–88% 80–81% 88–89% The fractional distribution varied between depending on production process, stabilization, initial metal concentration. In biosolids, only partitioning influenced by spiking, cleanup, washing. three (Cd, Zn) occurred either crystalline phase linked Fe oxide, organic matter, carbonate. not associated oxide. This demonstrated 99% 97% contents remained soil; however, cleanup generally decreased concentrations plants, leachate, and/or soil.