Novel Methods Of Genetic Toxicity Assessment For Integrated Wastewater And Environmental Water Samples

Integrated wastewater contains a large amount of poisonous and harmful pollutants, national wastewater discharge standards are just chromaticity, turbidity, COD, pH and other physical and chemical indexs so far, they are lack of toxic indexes of biological monitoring. Physical and chemical indexs can only reflect instantaneous concentration of pollutants, and they can’t reflect the pollutants for comprehensive toxicities and long-term effect of environment. Despite wastewater from many industries do the sewage treatment, but due to the imperfect discharge standards and not complete indexs, toxic pollutants in the waste water can often have carcinogenic, teratogenic, mutagenic effect, they have genetic toxicities and great harm to the environment,but now due to lack of genetic toxicities monitoring datas of integrated wastewater, it must make ecological environment, sustainable development of the economy and human health serious challenges and threats for China. Therefore, it’s imminent to study of genetic toxicities of pollutants in integrated wastewater.Through doing K2CrO7’s acute toxicity for Paramecium caudatums, compared with K2Cr2O7’s acute toxicity for Daphnia magna and zebrafish, the result showed Paramecium caudatum’s sensitivity is similar with Daphnia magna and higher than zebrafish.Through establishing the genetic toxicity test of Paramecium caudatum as a aquatic indicator,the result showed using Paramecium caudatum do biological toxic monitoring is feasible.In the paper dyeing wastewater, Liao River basin and the environmental water in Dalian’s representative samples as the research object.Paramecium caudatums were biological indicator, using single cell gel electrophoresis test (SCGE) detect integrated wastewater and environmental samples’s toxic characteristics. The acute toxicity results of dyeing wastewater showed24h-LC50of influent, anaerobic and effluent’s water samples were54%,41%,98%, respectively. The results of genetic toxicity showed6.25%and12.25%concentration influent and effluent made Paramecium caudatums’DNA damage significantly longer than the control group (p<0.01), but compared with influent,the DNA damage of effluent wasn’t significantly different. The results of proliferation rate showed more than50%concentration effluent inhibited Paramecium caudatums’proliferation.Although dyeing effluent’s physico-chemical indicators were in line with national dyeing wastewater discharge standards after they were treated by A/O process, the effluent still induced Paramecium caudatum’s acute toxicity, genetic toxicity was not significantly reduced. Through the correlation analysis between the physico-chemical parameters and acute toxicity index,the results showed the fatality rate and chemical indicators had no significant correlation,these results showed biological toxicity test can be an effective complement to the evaluation of chemical analysis, and provide the basis for dyeing wastewater industry’s comprehensive discharge standards.This study chose four typical sampling points of Liao River basin to analyse their comprehensive toxicities. The results of acute toxicity showed other three sampling points were no lethal effect except Shenyang section of HunHe basin downstream. The results of genetic toxicity showed that compared with control,the DNA damage of Dahuofang reservoir wasn’t significantly different, but the DNA damage of Fushun section of HunHe basin upstream, Shenyang section of HunHe basin downstream and Panjin section of Liao River basin were significantly different (p<0.01).The emissions of industrial wastewater and domestic sewage around the basin induced larger pollution for water. Results showed that the genetic toxicity could be used to reflect comprehensive toxicities evaluation of wastewaters as supplement of the acute toxicity.Through monitoring four environmental water sampling points of Dalian city, The results of acute toxicity and sub-chronic toxicity showed four sampling points didn’t induce Paramecium caudatums’lethal effect, they all didn’t have acute and sub-chronic toxicities. The results of proliferation rate showed that four sampling points were exposed to Paramecium caudatums, four sampling points had no inhibitory effect on the rate of Paramecium caudatums’proliferation. The same point in time,The proliferation inbibition rate of Paramecium caudatums which were exposed to the downstream of Malan river was greater than upstream, the proliferation inbibition rate of Paramecium caudatums which were exposed to the downstream of Chunliu river was greater than upstream. All results indicated that four sampling points’water qualities were good, and both river downstream water qualities were better than those of the upstream water qualities.By comparing zebrafish and paramecium as biological indicators,the results of toxic characteristics of dyeing wastewater showed Paramecium caudatums had higher sensitivity, and using Paramecium caudatums had many advantages. Paramecium caudatums’multiply is easier,we don’t need to make single cell suspension preparation step, we can accurately separate from living cells and dead cells and not need many samples,so paramecium can serve as a good biological indicator to evaluate the comprehensive toxicities of wastewater.