Applying factorial experiments to study the toxicity effects of heavy metal mixture on nitrifying granules
混合重金属对硝化颗粒污泥毒性作用的析因实验研究

The single toxicity of copper,zinc and cadmium to nitrifying granules were determined respectively.The joint toxicity of binary and ternary mixtures were studied by the application of factorial experiments.The results showed that the EC50 of 2 hours of Cu2 ,Zn2 ,and Cd2 were 95.23,62.11 and 12.48 mg/L,respectively.The resultant response surface models were of high qualities reflected by the R2 above 0.95.Furthermore,the prediction of the joint toxicity of metal mixtures can be well made based on the models obtained.It is feasible for factorial experiments to be applied in the study on the joint toxicity of mixtures in the environmental fields.