The Study Of The Toxic Effect Of Chemical Industry Sewage And Its Typical Pollutants On Fishes

In recent years, China is short of water resources and water pollution has become more and more serious. With the fast development of economy, the emission, conversion and transfer of more and more external pollutants into the water system result in the deterioration of water quality, worsen China’s water pollution and seriously imperil people’s health and the ecological safty. The issue of water environment safety has become one of the restrictive element of the sustainable development of China’s Socio-economic progress, and the water quality monitoring of water polluters has attracted more and more attention. The monitoring of water quality, the exact assessment of the degree of water pollution, the scientific evaluation of the status quo of water environment and polluters and the making of policies to protect the water environment are theoretically and practically significant to the sustainable utilization of water resources. The toxic effect of polluted water on fishes can directly reflect the pollution level of the receiving water, and the use of small fishes to monitor water pollution can supplement the regular water quality monitoring.The research aims to coordinate biological monitoring techniques and physical and chemical monitoring tools and to theoretically support the setting of technical specifications about biological and toxic monitorings of polluter sewage by sorting out sensitive and easy-obtained experimental fishes, and monitoring them biologically within the typical chemical industry polluter sewage, whose composite indicators will be assessed and whose toxicity, classified. The thesis selected five kinds of typical polluter sewage and assessed their biological toxicity comprehensively.The research sorted Brachydanio rerio, Xiphophorus helleri, Hyphessobrycon.innesi, Puntius tetrazona as experimental materials out of eight kinds of experimental fishes, such as Red nose scissors fish, Mahi fish, Short sauté,Green Jiang fish, Brachydanio rerio, Xiphophorus helleri, Hyphessobrycon.innesi, Puntius tetrazona; secondly, with the industry sewage experimental method (the acute toxicity test on fishes), it studied the toxic effect of five kinds of chemical industry sewage on the sensitive fishes, and classified the toxicity of the five kinds of sewage according to the classifying norms of industry sewage toxicity; meanwhile, it studied the acute toxicological effects of p-Nitrophenol on the four kinds of fishes to provide the theoretical basis for the subsequent monitoring of water living things. The findings were as follows:1. The findings of the acute toxicity test of the five kinds of sewage on the four kinds of fishes were:the test of the five kinds of sewage on the96h-LC50(volume percentage) of Brachydanio rerio, Xiphophorus helleri,Hyphessobrycon.innesi, Puntius tetrazona was:the fifth sewage was not fatal to the four types of fishes; sewage No.1,2.3on the96h-LC50of Brachydanio rerio was8.5%,20.8%,22.1%; sewage No.1,2,3,4on the96h-LC50of Xiphophorus helleri was8.6%,14.4%,18.3%,90.1%; sewage No.1,2,3,4on the96hLC50of Hyphessobrycon.innesi was7.7%,7.2%,12.8%,87.7%; sewage No.1,2,3,4on the96h-LC50of Puntius tetrazona was3.4%,4.8%,10.4%,85.3%.The half-fatal concentration of the4types of fishes gradually decreased over time. The toxicity increased and showed a certain degree of regularity. The sensitivity to the toxicity of chemical industry sewage was like this:Puntius tetrazona> Hyphessobrycon. innesi>Xiphophorus helleri> Brachydanio rerio.2. According to the recommended approach of ISO the classifying norms of industry sewage toxicity, and with the findings of the acute toxicity test on Brachydanio rerio, Xiphophorus helleri, Hyphessobrycon.innesi, Puntius tetrazona:the Tua-96h of sewage1was between11～30, of high toxicity; the Tua-96h of sewage2on Brachydanio rerio and Xiphophorus helleri was between4～7, of medium toxicity, yet on Hyphessobrycon.innesi and Puntius tetrazona was betweenl8～20, of high toxicity; the Tua-96h of sewage3was between4～10, of medium toxicity; the Tua of Brachydanio rerio in sewage4was less than1, of little or no toxicity, but the Tua of other three was between1～2, of low toxicity; the Tua of all fishes in sewage5was less than1, of little or no toxicity. 3. The96-LC50of the acute toxicity test of p-Nitrophenol on Brachydanio rerio, Xiphophorus helleri, Hyphessobrycon.innesi, Puntius tetrazona was11.5mg/L,8.5mg/L,5.4mg/L and2.5mg/L respectively. There was connection between p-Nitrophenol and the single toxicity test:the toxicity increased over time with its exposure in the air. The96h half-fatal concentration of the4types of fishes was different, and the reaction of the same pollutants to p-Nitrophenol was different. Thus, the sensitivity of different living things (fishes) to p-Nitrophenol was quite different.