乳酸发酵液淋洗铅锌矿尾矿坝口底泥中的重金属铅

Leaching removal lead in sediment at dam exit of the lead-zinc tailings using lactic acid fermentation production

为了降低尾矿中重金属对环境造成的危害,利用乳酸发酵液对铅尾矿坝口底泥进行了淋洗研究,从而探析低分子质量有机酸在土壤重金属淋洗修复中的应用前景。结果表明:乳酸对底泥中的Pb具有较好的去除率,当选择发酵菌种为米根霉,发酵时间为48 h,米根霉发酵生产的乳酸含量可达到14%;该发酵液对Pb的去除率达到了19.52%,与同一酸度纯乳酸淋洗铅的去除率仅差2.6%。从铅的形态分析可知,乳酸发酵液对尾矿坝口底泥中酸可提取态铅和可氧化态铅的去除率分别为80%和50%。利用发酵生产有机酸淋洗修复土壤中的重金属具有很好的潜力。

To reduce environmental pollution and hazards of heavy metals in the tailings,a kind of lactic acid fermented broth was used to leach the sediment at the lead-zinc tailing dam exit.And the application prospect in metals leaching and soil remediation by low molecular organic acid was also analyzed.The results show that the lactic acid leaching led to a good Pb removal efficiency.When the fermentation strain of Rhizopusoryzae was fermented for 48hours,14%produced lactic acid was achieved.The Pb removal rate through leaching by this fermentation liquor could reach 19.52%,which was 2.6%lower than that by pure lactic acid.Moreover,leaching bythe lactic acid fermented broth could remove 80%acid-soluble Pb and 50%oxidizable Pb from the sediment at dam exit of the lead-zinc tailings,respectively.Therefore,leaching technique using fermented organic acid to remove heavy metal in polluted soil has a great development potential.