Study On VOCs Analysis Methods And Soil Risk Screening Values In Typical Polluted Land Blocks In Hubei Province

In recent years,with the rapid development of industrialization,a large amount of organic pollutants have been discharged into the environment,posing a serious threat to human health and the ecological environment.Among these organic pollutants,volatile organic compounds(VOCs)are currently the most concerned.Among them,VOCs can enter the human body through pathways such as the respiratory tract and skin,producing "carcinogenic,teratogenic,and mutagenic" effects,commonly known as the "three carcinogenic" effect.When the concentration exceeds a certain limit,the human body will feel uncomfortable,and in severe cases,it can cause poisoning and even life-threatening effects.The soil risk screening value is the initial concentration of soil pollution,which can assist in effective investigation and assessment of contaminated land and provide important basis for land risk assessment.However,due to the vast territory,geographical conditions,soil characteristics,and other significant differences in China.Therefore,adopting a single standard for management will generate significant uncertainty.Therefore,it is of great significance to deeply understand the generation,migration and transformation mechanisms of VOCs,establish precise analysis and detection techniques for VOCs,and develop soil risk screening values.This study targets volatile pollutants in key polluting industry plots in Hubei Province,based on no method detection.Establish a detection method for volatile organic compound content in key polluted plots in Hubei Province using purge capture/gas chromatography-mass spectrometry technology;Based on the recommended model and parameters in the "Technical Guidelines for Soil Pollution Risk Assessment of Construction Land"(HJ 25.3-2019)(Ministry of Ecological and Environmental Protection2019),the soil risk screening values in key polluting industry plots in Hubei Province were calculated.The specific research results are as follows:(1)After reviewing the physicochemical properties and toxicity parameters of volatile organic compounds,36 target volatile organic compounds were selected based on the absence of detection methods.Specifically: vinyl chloride,1,3-butadiene,ether,isoprene,1,2-epoxypropane,dimethoxymethane,ethyl formate,isopropanol,1-chloropropane,1,1-dichloroethane,1-propanol,isopropyl isocyanate,ethyl acetate,methyl acrylate,cyclohexane,cyclohexene,thiophene,n-butanol,methyl methacrylate,chloroacetonitrile,sec-butyl acetate,dichloroacetonitrile,n-octane,methyl chloroacetate,acetylacetone Ethyl chloroacetate,furfural,allyl group glycidyl ether,cyclohexanone,p-ethyltoluene,o-ethyltoluene,isobutyl benzene,1,3-diethylbenzene,methyl benzoate,1,2,4,5-tetratoluene,diethyl thiophosphoryl chloride.(2)A method for detecting 36 volatile organic compounds in soil was established using a combination of purge and capture/gas chromatography-mass spectrometry technology.Respectively with 10 μg/kg,100 μg/kg,400 μg/kg or 400 μg/kg,2000 μg/kg,20000 μg/kg Conduct spiked recovery experiments at a concentration,conduct 7 parallel experiments,and calculate and analyze the results.Its detection limit is 0.31-13.04 μg/kg,with a precision of 1.42%～8.04% and a recovery rate of 85.51%～128.84%.(3)According to the exposure assessment model and risk expression in the "Technical Guidelines for Soil Pollution Risk Assessment of Construction Land"(HJ25.3-2019),a calculation method for soil risk screening values was derived based on the determination of exposure pathways and populations.Relevant literature was consulted to obtain localization indicators for polluted land in Hubei Province.Calculate the risk screening values of soil pollutants such as furfural,cyclohexene,isopropanol,cyclohexanone,ethyl acetate,1,3-butadiene,and methyl methacrylate in the polluted plots in Hubei Province.The first type of land use risk screening values are: 15.40 mg/kg,0.08mg/kg,770.68 mg/kg,2649.76 mg/kg,0.13 mg/kg,0.15 mg/kg,2286.36 mg/kg;The risk screening values for Class II land use are 53.94 mg/kg,0.27 mg/kg,15822.68 mg/kg,54125.39 mg/kg,0.45 mg/kg,0.54 mg/kg,and 44962.39 mg/kg,respectively.The calculation and analysis results provide technical reference for risk assessment of volatile organic compounds in contaminated soil.