重金属对污泥活性的影响

目的]研究重金属对活性污泥中微生物的影响。方法]以污水处理厂好氧池中的絮状活性污泥为材料,配制模拟废水研究铜、锌、铬、铅、汞等5种重金属对活性污泥的毒害效应及重金属中毒活性污泥培养后的活性恢复情况。结果]5种重金属均可降低活性污泥的COD去除率和污泥系统中微生物脱氢酶的活性,其中铜、汞的影响最明显,这2种重金属浓度为45mg/L时,系统的COD去除率降至50%。活性污泥的SVI值随重金属浓度的增加而升高。加入模拟废水曝气培养后,锌、铬、铅等重金属中毒的活性污泥可恢复活性,汞中毒的活性污泥不能恢复活性,铜中毒活性污泥恢复后的活性与铜浓度有关。结论]重金属可降低污泥系统的处理能力。

Effect of Heavy Metal on Activity of Sludge

Objective] The aim was to study the effects of heavy metals on microorganisms in activated sludge.Method] The flocculent activated sludge from aerobic pool of sewage treatment plant was taken as the material.The simulation wastewaters was prepared to study the toxic effects of 5 kinds of heavy metal such as copper,zinc,chromium,lead and mercury on activated sludge and its activity recovery condition after culture.Results] The removal rate of COD in activated sludge and the dehydrogenase activity of microorganisms in sludge system could be reduced by the 5 kinds of heavy metal,and the effects of copper and mercury were the most obvious.When the concns.of the 2 kinds of heavy metal was 45 mg/L,the removal rate of COD was decreased to 50%.The SVI value of activated sludge was increased with the increase of concns.of heavy metals.After cultured by simulation wastewater with aeration,the activity of activated sludge poisoned by zinc,chromium,lead could be restored,while that of activated sludge poisoned by mercury could not be restored.The activity recovery of activated sludge poisoned by copper was related to copper concns..Conclusion] The heavy metal could decrease the handling capacity of sludge system.