摘要
为反映实际场地源强或挥发通量的衰减对室内风险的影响,以某挥发性有机污染场地为例,在原有Jury模型基础上增加了建筑物底板及场地地层垂向异质性对传输通量的影响作用,比较了J&E模型与Jury模型在预测挥发通量,室内空气浓度、健康风险评估结果的差异及影响因素.结果表明:J&E模型预测进入室内的苯通量恒定,与实际场地存在源衰减不符.Jury模型可反映源通量衰减、包气带土壤和建筑底板的阻滞对室内浓度及风险的影响;Jury模型中的暴露区间设定是影响风险水平的关键因素.源形成初期,即T1情景下,暴露期只有两个点位超出可接受风险水平;中期T2情景下,4个点位超出风险可接受水平,后期T3情景下,7个点位超出风险可接受水平,而J&E模型为恒定源,不同时期均为7个点位超标.总体而言,Jury模型考虑了污染源衰减及上方覆盖土壤的阻滞作用,相对J&E模型更为合理.
To reflect the source or mass flux attenuation in actual contaminated sites,Jury model was improved by considering the effect of vertical heterogeneity of site lithology and sublab.The model was compared to the J&E model in predicting volatilization flux,indoor air concentration,health risk assessment.Finally the major influential factors were discussed by using an example of a benzene contaminated site in Beijing.The results showed that the benzene flux into the room predicted by the J&E model remained constant,which was inconsistent with the source attenuation in the actual site.In contrast,the volatilization flux of benzene predicted by the Jury model was initially the largest at the source surface and decreased exponentially with time.However,due to the blocking effect of the soil in the vadose zone and the building subslab,the flux entering the indoor air was relatively low at the beginning and increased with time.By the J&E model,the carcinogenic risk of 7sampling locations exceeded 10-6.However,with the Jury model,the determination of the exposure period was the key factor affecting the risk level.The exposure under the initial stage of source formation(scenario T1),only two locations in the exposure period exceeded the acceptable risk level.Under the mid-term(scenario T2),4locations in the exposure period exceeded the risk acceptable level,and only under late exposure state(scenario T3),7locations exceeded the acceptable level of risk.In general,compared with the J&E model,the Jury model was more in consistent with VOCs depletion in the fields by taking into consideration of sources attenuation and vadose blocking effect of mass fluxes.
作者
李吉鸿
钟茂生
姜林
张文毓
马琳
郝辰宇
LI Ji-hong;ZHONG Mao-sheng;JIANG Lin;ZHANG Wen-yu;MA Lin;HAO Chen-yu(Beijing Municipal Research Institute of Eco-Environmental Protection,Beijing 100037;National Engineering Research Centre of Urban Environmental Pollution Control,Beijing 100037,China;Beijing Key Laboratory for Risk Modeling and Remediation of Contaminated Sites,Beijing 100037,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第11期5924-5932,共9页
China Environmental Science
基金
国家自然科学基金资助项目(42177404)。
