杭州某退役污水处理厂退役场地污染调查与健康风险评估

DECOMMISSIONING SITE INVESTIGATION OF POLLUTION AND HEALTH RISK ASSESSMENT OF A RETIRED SEWAGE TREATMENT PLANT IN HANGZHOU

通过对杭州某污水处理厂退役场地环境总体质量进行调查分析,得出场地主要超标特征污染物是锌、镍,污染区域主要分布在内堆场区域,内堆场土壤样品中重金属超标率为29%,最大超标深度为4 m,污染深度主要集中在0~100 cm深度土层中。通过健康风险评估方法对退役场地在居住用地暴露情景下进行风险评估,评估结果表明,退役场地致癌风险较小,存在一定的非致癌风险,镍和铬是主要的非致癌风险污染物,主要的暴露途径是经口摄入暴露,基于退役场地后续开发利用规划,建议采用外运处置、客土封闭等技术对场地污染土壤进行修复。

Through the investigation and analysis of the overall quality of retired site environment for a sewage treatment plant in Hangzhou,it was known that the main overproof characteristics pollutants were zinc and nickel,the polluted areas were distributed within the site and the overproof rate of heavy metals in the soil samples was 29%; the maximum overproof depth of pollution was 4 m and distributed mainly in 0~100 cm soil depth. Through the health risk assessment method,the risk of the decommissioning site under residential exposure scenarios was assessed,the evaluation results show that on the decommissioning site,cancer risk is low,there is a certain non-cancer risk,nickel is the main carcinogenic pollutant,nickel and chromium are the major non-carcinogenic risk pollutants,the main route of exposure is through oral ingestion exposure. Based on subsequent development and utilization planning of the site,it was recommended that clay and soil from outside should be used to remedy the polluted soil on the site.