Bio-Toxic Effects Of Influent And Effluent From Sewage Treatment Plant In Shijiazhuang

At present,the evaluation of urban sewage quality in China is based on traditional physical and chemical indicators such as Chemical Oxygen Demand,Total Nitrogen,Total Phosphorus and Ammonia Nitrogen.However,the detection of these conventional physical and chemical indicators does not fully reflect the actual biological effects of urban sewage.Urban sewage discharges still have the potential to have a negative impact on human health and the ecological environment of the relevant waters.This dissertation focuses on influent,secondary water and effluent from Shijiazhuang sewage treatment plant A,B,C.Selenastrum capricornutum,Brachydanio rerio,Vibrio Qinghaiensis Q67,and the root tip cells of broad Bean were applied to evaluate the acute toxicity and genotoxicity of wastewater.Meanwhile,to comprehensively evaluate the reduction performance of typical secondary treatment and deep treatment process on the biological toxicity,TU was performed.and provide scientific basis for the safe discharge of urban sewage and water quality monitoring.Combined with ICP-MS and GC-MS,the metal and organic content in water samples were determined and analyzed by digestion and solid phase extraction(SPE)to identify the characteristic toxic substances in urban sewage.On this basis,the typical toxic substances zinc,manganese,naphthalene(NAP),anthracene(ANT)were screened to investigate the physiological response of broad bean under heavy metal and polycyclic aromatic hydrocarbon stress.The results shows:1)The physical and chemical indicators of water discharge from the three municipal sewage treatment plants has reached the requirement of national.2)The biotoxicity evaluation analysis showed that the A,B and C municipal wastewater treatment plants were treated with A~2O process and advanced treatment process,the biological toxicity still detected for the three effluent.3)According to the deep treatment process of three sewage treatment plants,the capable of removing biological toxicity is wetland process>sand filtration+UV process>ozone+UV process.4)Quantitative analysis of heavy metals and organic matter in tested water samples showed that the contents of heavy metals and polycyclic aromatic hydrocarbons in sewage were at a low level.With the increasing of typical pollutants such as Zn,Mn,NAP and ANT solutions,the protein content of broad bean leaves increased first and then decreased,the chlorophyll content decreased gradually,the SOD content increased first and then decreased tendency,the MDA content increased gradually.This finding indicated that heavy metal and polycyclic aromatic hydrocarbon pollution may exert obvious ecotoxicological effects on the growth of broad Bean.The research provide a scientific basis for the safe discharge of sewage through discussion on the biological toxicity and identify the toxic substances of the effluent from the three sewage treatment plants in Shijiazhuang.