Cu^(2+)和Cd^(2+)对草履虫的毒性试验

Experimental Study on the Toxicity of Cu^(2+) and Cd^(2+) to Paramecium

[目的]为水体环境监测中废水排放安全性评价提供参考依据。[方法]通过单一急性毒性试验和联合毒性试验,研究了金属离子Cu2+和Cd2+对草履虫的急性毒性和联合毒性。[结果]在单离子急性毒性试验中,Cu2+和Cd2+对草履虫的毒性随浓度的增高而增大,且均呈明显的剂量效应。Cu2+的1h半致死浓度(LC50)为0.32mg/L,而Cd2+的1h半致死浓度(LC50)为0.96mg/L。当Cu2+和Cd2+共存时,Cu2+的1h半致死浓度(LC50)为0.24mg/L,Cd2+的1h半致死浓度(LC50)为0.19mg/L,2种金属离子表现为协同作用。[结论]在废水排放中,不但要考虑单种金属离子对水生生物的毒害作用,而且要重视2种或多种金属离子共存时它们对水生生物的毒害作用。

[Objective] The research aimed to provide reference basis for wastewater discharge safety evaluation in the water environment monitoring. [Method] In single acute toxicity test and joint toxicity test, the acute toxicity and joint toxicity of heavy metals Cu^2＋ and Cd^2＋ to paramecium was studied. [Result] In acute toxicity test of single ion, the toxicity of Cu^2＋ and Cd^2＋ were augmented with the increasing of concentration and both of them showed obvious dose effects. The median lethal concentration （LC50） of Cu^2＋ in lh was 0.32 mg/L and that of Cd^2＋ was 0.96 mg/L. When Cu^2＋ and Cd^2＋ coexisted, the median lethal concentration （LC50） of Cu^2＋ in lh was 0.24 mg/L and that of Cd^2＋ was 0.19 mg/L. And 2 kinds of heavy metals showed an synergistic effect. [Conclusion] In the process of wastewater discharge, not only the toxic effect of single heavy metal ion to aquatic organisms should be considered, but also much attention should be paid to the toxic effect of 2 or many kinds of heavy metal ions on aquatic organisms when they coexisted.