河北省某大型焦化厂地下水中多环芳烃的污染特点、源解析及生态风险评价

Analysis on Contamination Characteristics,Pollution Source Identification and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons of Groundwater in a Large Coking Plant Site of Province

为研究焦化厂地下水中美国EPA优先控制的16种多环芳烃(PAHs)的分布特点和污染来源,本研究联合使用统计技术、正定矩阵因子分析(PMF)模型和风险商值法,深入分析了焦化厂地下水中PAHs的分布规律,定量解析了PAHs的污染来源,并且对其生态风险进行了科学评价.结果表明,焦化厂地下水中16种PAHs的总检出率较高,达到46.7%.地下水中∑_(16)PAHs的浓度范围是n.d.~444.9μg·L^(-1),均值为1.88μg·L^(-1).不同生产车间地下水中PAHs的浓度存在明显差异,其中污染最重的车间位于焦油精制区,地下水中∑_(16)PAHs的浓度为444.92μg·L^(-1).应用PMF源解析模型,识别出该焦化厂地下水中PAHs有二类污染源:一是石油的燃烧源,二是煤和生物质燃烧以及石油类的泄漏,二种污染源对焦化厂地下水中PAHs的贡献率分别为38.6%和61.4%.焦化厂地下水中∑_(16)PAHs处在高生态风险等级,且有53.4%的地下水采样点单体PAHs的生态风险处在高风险等级.综上可见,针对焦化场地地下水环境治理与修复工作亟待开展.

Polycyclic aromatic hydrocarbons(PAHs),as a highly toxic persistent organic pollutant,are commonly found in soil and water environments.In recent years,the pollution of PAHs in groundwater has attracted wide attention from scientists.To study the pollution characteristics and sources of polycyclic aromatic hydrocarbon in groundwater of the coking site,16 PAHs priorly controlled by the US EPA were analyzed and discussed.In this study,we identified the contamination characteristics of PAHs in groundwater,analyzed the pollution sources of PAHs,and evaluated the ecological risk of PAHs in the coking site by combining statistical techniques,the positive matrix factorization(PMF) model,and risk quotient(RQ) methods.The results indicated that the total detection rate of PAHs in groundwater of the coking plant was 46.7%.The concentrations of PAHs in groundwater of the coking plant ranged from below the detection limit to 444.9 μg·L^(-1),with the average value of 1.88 μg·L^(-1).The concentration of PAHs in the groundwater of different production workshops was significantly different.The most polluted workshop was in the tar-refining area,and the concentration of 16 PAHs was 444.9 μg·L^(-1).Based on the PMF model,we identified the two primary contamination sources of PAHs in groundwater of the coking plant:(1) oil combustion and(2) coal and biomass combustion and oil leakage.The contribution ratios of the two sources to PAHs of groundwater were 38.6% and 61.4%,respectively.The results of the ecological risk assessment indicated that ∑_(16)PAHs in groundwater of the coking plant had high ecological risk,and the ecological risk of single PAHs in 53.4% of the groundwater sampling site was at a high ecological risk level.In conclusion,it is urgent to carry out the treatment and restoration of the groundwater environment in the coking plant site.