Characteristics And Evaluation Of Groundwater Organic Pollution In A City Of Hebei Province

With the rapid development of urbanization,the infiltration of urban sewage,landfill leachate,pesticides and chemical fertilizers have led to the increasing organic pollution of groundwater,which has endangered the local water supply security.Organic pollution has brought great health risks to the public.The prevention and control of organic pollution of groundwater is closely related to the vital interests of the people,which has attracted great attention of the party and the government.The study area has done a lot of related basic work in the past,such as carrying out hydrogeological survey,setting up hydrogeological monitoring station,identifying environmental geological problems and so on,which provide the basis for this study,but the research on organic pollution is not deep enough.This paper aims to explore a feasible evaluation method of organic pollution status,understand the characteristics of pollutant content and spatial distribution and the harm to human health,provide scientific basis for protecting groundwater environment,provide basic data for ensuring urban safe water supply,and have great significance for improving the quality of drinking water for people.In this paper,through the analysis results of water samples in the study area,the detection rate and over standard rate of organic pollution in the study area are analyzed,and the spatial characteristics of organic pollution in groundwater are analyzed by combining MAPGIS;seven pollutants exceeding the standard are selected and evaluated by using the improved BP neural network,including the expansion of training samples and the algorithm,the results were compared with traditional single index pollution standard index method and parameter grading score superposition index method.In order to further understand the harm of organic pollution to human health,based on the "NAS four step method",this paper adopts the exposure parameters which are closer to the residents in China to carry out the health risk assessment research in the study area,and analyzes the carcinogenic risk and non carcinogenic risk results from three aspects of "pollutant types,exposure routes,different sampling points".The research shows that the detection rate of organic matter in the study area is high,but the rate of exceeding the standard is low,and the overall situation is mild pollution.The organic pollution is mainly concentrated in the middle old urban area,which has formed a local pollution area,and this is closely related to the large number of polluting enterprises distributed here,formimg the trend of expanding from the middle to the surrounding areas.In this paper,the detection limit is introduced to establish the BP artificial neural network model After analysis,BP neural network is more reasonable than the traditional method,and can be better used in the evaluation of organic pollution status;health risk assessment shows that the carcinogenic risk is generally high,the main contribution of carcinogenic risk is chloroform,and the main contribution of non carcinogenic risk is benzopyrene It was found that both carcinogenic risk assessment and non carcinogenic risk assessment,respiratory inhalation pathway was the most important contribution factor.