The hazard of heavy metals in sewage sludge is one of the most important factors that influences land use;the hazard of heavy metals not only depends on the amount but also on the speciation,which could react on the migration and the bioavailability of heavy metals.The experiment studied the speciation of heavy metals(Cu,Zn and Pb) after composting of sewage sludge including sawdust as regulator and fly ash as a passive agent.The results showed that composting could make Cu more active but adding fly ash co...