Bioleaching of heavy metals from brooklet sediment by Thiobacillus ferrooxidans and Thiobacillus thiooxidans

Thiobacillus ferrooxidans(T.f) and Thiobacillus thiooxidans(T.t) obtained with separation and purifying from acid mine wastewater. Utilizing these two kinds of Thiobacillus on Cd,Cr,Pb,Ni,Cu,Zn 6 kinds of heavy metals of Guangzhou Guocun Brooklet sediment was to go on sequencing bioleaching test. T.f bacteria leaching out ability on heavy metals was higher than on T.t bacteria. The leaching out rate of T.f bacteria on Cd,Cr,Ni,Cu,Zn could reach highest 60%,45%,70%,90%,75%,T.t bacteria however was respectively 45%,34%,50%,65%,55%. These two on Pb removal rate was matched,all was almost 25%. Supplying different substrate sulfur powder and ferrous to T.f bacteria,the leaching out effects on 4 kinds of metals Cd,Ni,Cu,Zn did not have obvious influence,and on leaching out of Cr,Pb,the leaching out effect of sulfur powder treating was more letter. Meanwhile,adding sulfur powder and ferrous to T.f bacteria,thus its leaching out effect was lowered,might be that sulfate and ferric T.f bacteria metabolized reacted to produce M2Fe6(SO4)4(OH)12(M=K+,Na+,NH4+) that produced co-sediment with the dissolved out heavy metals,thus lowering its leaching out effect.