Removal of Heavy Metals in Sewage Sludge by Bioleaching: A Review

摘要

Bioleaching technology is an effective and potential method for removal of heavy metals in sewage sludge,which is important for the land utilization of sewage sludge.The major bacteria of bioleaching are Acidithiobacillus ferrooxidans (At.thiooxidans) and Acidithiobacillus thiooxidans (At.ferrooxidans).Insoluble metal sulfide is oxidized to metal sulfate,and the released photon makes the solution acidification.For the low pH 2～4,partial insoluble heavy metal solves into the liquid.Then the heavy metal cation is removed from sewage sludge through solid-liquid separation.In this study,the researched about the main factors of bioleaching are reviewed.Those factors are:sludge,energy substrate,aeration,temperature.The research about main influence factor of bioleaching has been reviewed also.