BACTERIAL LEACHING PROCESS

摘要

The present invention relates to a process for removing heavy metals and substantially destroying indicator bacteria pres- ent in municipal sludges, which comprises: lowering, under aerobic condition s, the pH of a municipal sludge from about 7 to 8 to about 2.0 to 2.5 by adding to said sludge 10 % by volume of an inoculum containing a mixture of microorganisms comprising Thi- obacillus thiooxidans ATCC X5127 and Thiobacillus thioparus ATCC 55128 with 1 to 3 g per litre of sulphur, and incubating for a period of at least 40 hours where the heavy metals originally present in said sludge have been substantially solubilized and the concentration of the indicator bacteria has been lowered to a non-toxic leve l; and recovering the metals from the low pH treated sludge of step a).