Study On The Biological Toxicity Assessment Of Pesticide Wastewater

This dissertation focuses on the effluent from 12 pesticide factory and influent and effluent from one pesticide industrial park, selection different trophic levels of different aquatic organisms in the ecosystem luminescent bacteria(disintegrator), selenastrum capricornutu m(producers),zebrafish egg(secondary consumer),daphnia magna(primary consumers), Salmonella typhimurium as a biological subjects,as test organisms, consider relatively luminosity, growth inhibition rate, abnormal rates or mortality, mortality, and umuC-gene induction ratio as the evaluation index, study the acute toxicity effect and genetic toxicity to the five test organisms of pesticide industrial park sewage treatment plant influent and effluent. Test results are expressed by HgC l2 toxicity equivalent, Median Effective Concentration which EC50, toxic unit TUa and common genetic toxicity induction ratio IR. The comprehensive results make preliminary conclusions by use the acute toxicity and genetic toxicity tes :(1) Of 12 pesticide production enterprise’s 14 kinds of waste water in HgC l2 toxicity equivalent,EC50,TUa,LID, there are 5 kinds of water samples show high biological toxicity, 4 kinds of water samples show medium biological toxicity, 5 kinds of water samples show micro biological toxicity or non-toxic.(2) Influent samples’ Vibrio fischeri, selenastrum capricornutum,zebrafish egg, daphnia magna, acute toxicity test EC50 are >100%,45.18%,>100%,87.74%; TUa are <1,2.21,<1,1.14. genetic toxicity induced rate IR<1.5. LID are 4,8,2,1. In evaluation of influent samples, selenastrum capricornutum acute toxicity test is the most sensitive test, the specific sensitivity order is selenastrum capricornutum>luminescent bacteria>daphnia magna > zebrafish egg.(3) All the Effluent samples’ luminescent bacteria, selenastrum capricornutum,zebrafish egg, daphnia magna, acute toxicity test acute toxicity test EC50 are >100%;TUa are<1. genetic toxicity induced rate IR<1.5. The comprehensive toxicity assessment by use PEEP index is medium toxic wastewater. In evaluation of effluent samples, selenastrum capricornutum acute toxicity test is the most sensitive, the specific sensitivity order is selenastrum capricornutum>luminescent bacteria>daphnia magna > zebrafish egg. Results show that after the treatment, waste water to all the participants did not produce obvious toxicity inhibition, biological toxicity decreased significantly.(4) The PEEP of the pesticide industrial park wastewater is 4.45.The comprehensive to xicity assessment by use PEEP index is high toxic wastewater. The PEEP of the influent is 4.31,high toxic wastewater and The PEEP of the effluent is 3.81, medium toxic wastewater.(5) Umu genetic toxicity test results show that the inlet and outlet genetic toxicity of water samples were not visible.According to PEEP index evaluation of pesticide park dra inage water samples has no genetic toxicity, this indicates that the pesticide wastewater had no o bvious correlation between the acute toxicity and genetic toxicity.(6) Although after processing of sewage treatment plant, waste water of the physical and chemical index has reached the requirement of national or local standards, but there are still high biological toxicity.So when we formulate wastewater discharge standard,we should consider to make comprehensive toxicity of wastewater drainage standard.