溶解氧突变指数对活性污泥重金属中毒的预警

Early Warning of Heavy Metal Poisoning of Activated Sludge Indicated with Dissolved Oxygen Mutation Index

以溶解氧(DO)突变为活性污泥中毒的预警指标,研究Cu2+、Cr6+、Pb2+、As5+4种重金属对活性污泥的毒性,并对预警活性污泥重金属中毒的测试参数进行优化。结果表明在相同的反应条件和重金属浓度(15 mg/L)下,4种重金属抑制活性污泥活性导致DO突变量分别为0.87、0.6、0.4和0.75 mg/L,其顺序为Cu2+>As5+>Cr6+>Pb2+,活性污泥对重金属铜中毒更加敏感。当As5+和Cr6+浓度由3 mg/L提高至15 mg/L时,活性污泥的DO突变量分别由0.32和0.27 mg/L上升至0.75和0.53 mg/L,表明随进水中As5+、Cr6+浓度增加,对活性污泥抑制性越强,存在剂量-效应关系,因此溶解氧突变可作为活性污泥重金属离子中毒的判别指标,快速预警污水处理厂进水重金属引发活性污泥中毒与否,为污水处理厂稳定运行提供技术支持。

The early warning of activated sludge poisoned by heavy metals as Cu^2＋,Cr^6＋,Pb^2＋ and As5＋ was studied with dissolved oxygen mutation index.The parameters of early warning of activated sludge poisoning were optimized.With a certain condition and common dosage of heavy metals（15 mg /L）,the dissolved oxygen mutation by these heavy metals are 0.87,0.6,0.4 and 0.75 mg /L,which indicates the biological inhibition order is Cu^2 ＋ As^5 ＋ Cr^6 ＋ Pb^2＋.When concentrations of As^5＋ and Cr^6＋ increase from 3 mg /L to 15 mg /L,the dissolved oxygen mutations increase from 0.32,0.27 mg /L up to 0.75 and 0.53 mg /L,respectively.With a rising dosage of heavy metals,the activated sludge＇s poison measured by dissolved oxygen mutation index is enhanced.Thus,the dissolved oxygen mutation index can be used as early warning of the activated sludge poisoned by heavy metals in wastewater treatment plant.