上海某焦化场地土壤多环芳烃污染特征及生态风险评价

Pollution Characteristics and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soils of a Coking Site in Shanghai

以上海市某焦化场地为例,根据历史污染识别情况采集8个点位不同深度的土壤样品,分析16种多环芳烃(PAHs)的含量,分析PAHs的污染特征,采用质量基准法评价PAHs生态风险,运用比值法分析判断PAHs来源。结果表明,本次研究的焦化场地土壤样品的PAHs总含量为ND~17.21 mg·kg^(-1),平均含量为3.47 mg·kg^(-1)。PAHs主要在表层土壤中累积。16种PAHs中以高环类PAHs为主,其中苯并(a)芘超过一类筛选值,样品超标比例为12.5%。场地绝大部分土壤样品处于低生态风险或无生态风险,粗苯车间为中等生态风险。场地土壤中的PAHs来源主要为燃烧源,燃烧源为煤炭/生物质及石油混合源。

Soil samples were collected from 8 sites with different depths from a coking site in Shanghai according to the historical pollution identification.The content of 16 polycyclic aromatic hydrocarbons(PAHs)was detected to analyze the pollution characteristics of PAHs.The ecological risk of PAHs was evaluated by the quality benchmark method,and the source of PAHs was determined by the ratio method.The results showed that,the total content of PAHs in the soil samples from the coking site in this study was ND~17.21 mg·kg^(-1),with an average content of 3.47 mg·kg^(-1).PAHs mainly accumulate in the surface soil.Among the 16 types of PAHs,PAHs with high ring numbers are the main ones in 16 PAHs.The content of Benzo(a)pyrene was high than the standard value,and the proportion of samples exceeding the standard is 12.5%.The vast majority of soil samples on the site are at low or no ecological risk,while the crude benzene workshop was at medium ecological risk.The main source of PAHs in the site soil is combustion,which is a mixture of coal/biomass and petroleum.