【摘要】 采用发光细菌毒性、活性污泥脱氢酶毒性、硝化抑制毒性3种方法测定Hg、Cd、Zn、Pb4种重金属对活性污泥微生物的毒性,并对测定结果进行了比较。结果表明,发光细菌毒性测定方法的灵敏度最高,测得的重金属半数有效浓度(EC50)最低,4种重金属对发光细菌发光强度的抑制程度由大到小顺序依次为Hg>Cd>Zn>Pb;活性污泥脱氢酶毒性和硝化抑制毒性的测定结果与发光细菌毒性测定结果相比,灵敏度相对较低,测得的重金属EC50相对较高,测得的活性污泥脱氢酶活性的抑制程度由大到小顺序依次为Cd>Hg>Zn>Pb,与测得的活性污泥硝化速率抑制程度大小顺序一致,但2者测得的EC50有所差别。为了更准确的判定重金属对活性污泥微生物的毒性影响,至少应取不同的重金属毒性终点指示指标做一组毒性实验,而不能以发光细菌毒性测定结果作为唯一的判定依据,这可能会过分夸大重金属对污水处理工艺的冲击能力,导致污水处理成本无谓增加。更多还原

【Abstract】 The bio-toxicity of Hg,Cd,Zn and Pb on microorganism in activated sludge was detected by the three methods of detecting luminous bacteria toxicity,dehydrogenase activity of activated sludge and nitrification inhibition rate. The results showed that luminescent bacteria toxicity method presented the highest sensitivity and the lowest EC50 value;the bio-toxicity of 4 heavy metals followed the sequence of Hg>Cd>Zn>Pb. The other two methods had relatively low sensitivity and high EC50 value,and the order of heavy metal bio-toxicity was Cd>Hg>Zn>Pb. In order to determine the toxicity of heavy metal pollutants more accurately,at least one set of toxicity test should be targeted at activated sludge,luminescent bacteria biotoxicity could not be the sole basis to determine the short-term impact on the wastewater treatment capacity,which would result in unnecessary costs of wastewater treatment significantly.更多还原