Cd污染土壤生物毒性的发光菌法测定及评价

Detection and Evaluation of Biotoxicity of Cd Contaminated Soil by Luminescent Bacteria

[目的]测定及评定Cd污染土壤的生物毒性。[方法]选取青海弧菌Q67(Vibrio qinghaiensis sp.-Q67)为指示微生物,采用急性毒性微孔板法,发光抑制率为测试指标,利用发光菌方法评价施用不同调理剂的Cd污染土壤的生物毒性。[结果]Cd污染土壤提取液对发光菌的发光有抑制作用,并随着Cd浓度的增加,发光菌的发光强度逐渐减小,其发光抑制率与Cd浓度呈正相关,Cd的EC_(50)为10.97 mg/kg。与CK对比,施用白云石的处理显著降低了Cd的有效性及Cd的生物毒性。Cd有效性和青海弧菌的发光抑制率降低幅度分别为29.95%、15.35%;用发光菌方法测得Cd的生物毒性与化学方法测得Cd的有效性具有显著的正相关。[结论]结合化学分析与生物毒性检测可为污染土壤评价与风险评估提供依据。

[Objective]To determine and evaluate the biotoxicity of Cd contaminated soil.[Method]Vibrio qinghaiensis sp.-Q67 was selected as indicator organisms,luminescence inhibition rate was the test index,the toxic micro-pore-plate method was used to evaluate the biotoxicity of Cd contaminated soil with different conditioners.[Result]The extracts of Cd contaminated soil had an inhibitory effect on the luminescence of luminescent bacteria.With the increase of Cd concentration,the luminescence intensity of luminescent bacteria gradually decreased.The luminescence inhibition rate was positively correlated with the Cd concentration.The EC_(50) of Cd was 10.97 mg/kg.Compared with CK,the application of dolomite significantly reduced the availability of Cd and the biotoxicities of Cd,the availability of Cd and the luminescence inhibition rate of Vibrio qinghaiensis sp.-Q67 decreased by 29.95%and 15.35%respectively.There was a significant positive correlation between the biotoxicity of Cd measured by luminescent bacteria method and the effectiveness of Cd measured by chemical method.[Conclusion]The combination of chemical analysis and biological toxicity test can provide a basis for comprehensive evaluation and risk assessment of contaminated soil.