Study on the toxic effects of Cu~(2+) and Ni~(2+) on nitrifying granules

The single toxicity of Cu2+and Ni2+to nitrifying granules were determined respectively.The joint toxicity of Cu2+ and Ni2+ mixtures were studied by the application of factorial experiments.The results showed that the EC_50 of Cu2+ and Ni2+ were 95.23 and 26.45 mg·L-1,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 Cu2+ and Ni2+ mixtures could be well made based on the models obtained.The joint toxic of Cu2+ and Ni2+ mixtures showed antagonistic.