Toxic effects of copper on inhibition of the growths of unicellular green algae.

：A standard test method for evaluating the toxicity of chemicals to algae was applied; and 96h-EC50 of copper on inhibition of the growths of Chlorella pyrenoidosa, Scenedesmus obliquus, Closterium lunula were calculated as 67,51 and 202μg/L respectively using the method of probability unit for data treatment based on the test results. The results from the X2 test of each dose-response equations showed that 96h-EC50s calculated were all precise and credible. It was found that S. obliquus was most sensitive to copper but C. lunula had a strong resistibility to copper. The toxicities of copper on inhibition of the growths are different. The order of algae sensibility to copper was: S. obliquusC. pyrenoidosaC. lunula. The different volumes of cells of different species of algae and the different amounts of functional groups containing sulfur on algae surface were the main cause for the different sensitivity of algae to copper.