Joint Toxicity Of Cu, Zn And Substituted Nitrobenzene To Photobacterium Phosphoreum

At present,there is compound pollution with heavy metals and organic pollutant in natural water body.Studing of joint action of them is more practical significance for ecological risk acsessment of water body.The single toxicity of Cu,Zn and 11 kinds of substituted nitrobenzene to photobacterium phosphoreum were determined respectively. On the basis of single toxicity, the joint toxicity of binary mixtures of Cu, Zn in the concentrations of 0.2, 0.5 and 0.8 times of EC₅₀ and substituted nitrobenzene were measured and 15min-EC₅₀ values were determined, and conctrating with The single toxicity, the results show that:when joint with copper, the joint toxicity increased;when joint and zinc,different compounds shows different law.Toxic Unit(TU), Additive Index(AI), Mixture Toxicity Index(MTI) and similar parameter(λ) were used to evaluate the joint toxicity of Cu, Zn and 11 kinds of substituted nitrobenzene to photobacterium phosphoreum. The results indicate that: the joint toxicity of binary mixtures of Cu in the concentrations of joint with copper, when the concentration is 0.2EC₅₀, additivity were obvious; when the concentrationis is different, substituted nitrobenzene showed different trend, the joint toxicity is more obvious, and when the concentration is 0.8EC₅₀, antagonism is main. Joint with zinc,p-nitrobenzoic acid showed strong synergism, most of the other substituted nitrobenzene mainly showed antagonism and Partial addition .The joint toxicity of binary mixtures and the same substituted nitrobenzene to photobacterium phosphoreum were different in different concentration of heavy metals.Even if the type were the same, the strength might be different. Different substituted nitrobenzene showed different trend;In the same concentration of heavy metals, using different methods evaluated,results might be different,but the trend were the same.