Water Source And Municipal Water Quality Analysis And Healt Risk Assessment Of Z City

In order to explore the water source and drinking water quality in Z City,multiple groups of water samples of source water,factory water and terminal tap water in the study area in 2021 were collected.Three detection points which are S,N₁and N₂ were set for source water and 34 indicators were detected.Two detection points which are A and B were set for factory water and 106 indicators were detected.And two detection points which are A₁ and B₁ were set for the terminal tap water and 35 indicators were detected.On the basis of Standard for groundwater quality,Nemero index method and principal component analysis of water source water quality.On the basis of Standard for Drinking Water analysis of water quality of factory water and terminal tap water.On the basis of Exposure Factors Handbook of Chinese Population and health risk assessment model,the risk of water source,factory water and terminal tap water was calculated.The result of research shows that:1.Each test point in the water source accorded with the class IV standard of Standard for groundwater quality.In terms of Nemero index method,the water quality of the three detection points is excellent and the point N₂ has the lowest Nemero comprehensive value.In terms of principal component analysis,19 indexes in the water source can be represented by two comprehensive indexes,and the point S has the lowest score.2.The concentration of pollutants at each detection point of the factory water and terminal tap water conforms to the Standard for Drinking Water.3.The health risk evaluation results showed that more than 98%of the risk value of water source,factory water and terminal tap water was contributed by oral exposure.The risk value of skin exposure only accounted for a very small proportion.The risk of carcinogens in oral exposure was much higher than that of non-carcinogens.The risk value of Cr⁶⁺was the highest,and the highest risk value was 1.53×10^-4a^-1.The non-carcinogenic risk of oral exposure at each point was mainly contributed by pollutants NO₃^-and F^-.4.Compared with the water source,the quality of the factory water is significantly improved.Because of the process of dissolution,precipitation,and so on,a number of indicators detected concentration compared with the factory water had fluctuated.According to the health risk assessment results,the carcinogenic pollutants Cr⁶⁺and non-carcinogenic pollutants NO₃^-and F^-in the water source have high potential risks.But after the treatment of water plant,the risk of each index is reduced and the water quality index is in line with the Standard for Drinking Water.5.Based on the results of water quality detection,Nemero index method,principal component analysis,health risk evaluation and various uncertainties in the evaluation process,the following suggestions are put forward:（1）There is a phenomenon that microbial indexes in water samples of water source exceed the classⅢof Standard for groundwater quality.The reasons can be detected and analyzed according to the water environment and COD_Mn and other related indexes.（2）According to the health risk assessment results,the carcinogens Cr⁶⁺,non-carcinogens NO₃^-and F^-in the water source of the study area have a high potential risk.Therefore,relevant treatment methods can be added for these three pollutants in the treatment stage of the water plant.The thesis carries on the water quality detection about each kind of water sample.Nemerow index and principal component analysis were used to evaluate water quality of water source.The risk values of exposure through different routes of water source and drinking water were calculated.According to the research methods and results of this thesis,water pollution situation of water source and the risk of the drinking water can be known.Effective suggestions are put forward to improve the quality of drinking water.The thesis has important practical significance and reference value.