Synergistic effects of Cl-donors on heavy metal removal during sewage sludge incineration

Sewage sludge is an alternative source of phosphorus, but high metal contents limit its application. This study investigated the effect of temperature, combustion environment (muffle furnace and bubbling fluidized bed reactor), and Cl-donors use (singularly or combined) on heavy metal removal during the thermal treatment of sewage sludge. The highest heavy metal removal rates were achieved primarily in the muffle furnace compared to the reactor, with 850 °C being identified as the optimal temperature. Moreover, single Cl-donors demonstrated higher removal efficiencies than their combinations, which was markedly apparent in the case of Pb.