淮河中下游底泥中PAHs的分布及其生态风险评价

Distribution and ecological risk assessment of PAHs in sediments from Huaihe River

通过使用气相色谱质谱仪(GC/MS)测定淮河中下游底泥中多环芳烃(PAHs)单体的含量,探讨其分布特征及进行污染物生态风险评价。结果表明:淮河中下游底泥中PAHs含量总平均值为293.8ng·g-1,变化范围较大,总体呈中游高下游低的趋势;PAHs的种类和环数分布及菲/蒽、荧蒽/芘比值显示何台渡口至新集乡段底泥中的PAHs主要来源于化石燃料的高温燃烧与裂解,而安淮村至小河头段主要来源于化石燃料的低中温不完全燃烧或天然成岩过程;对照有关底泥的生态风险评价标准,淮河中游平圩和洛河段可能具有生物负效应,而其它地区的潜在生态风险则很小。

The individual concentrations of polycyclic aromatic hydrocarbons （PAHs） in sediments from the middle and lower reaches of Huaihe River were determined by GC/MS, their distribution characteristics were discussed, and their ecological risks were assessed. The results showed that the average concentration of PAHs in sediments was 293.8 ng.g^-1. The concentrations had a wide variation range, generally taking on a trend from high in the middle reach to low in the lower reach. Both the varieties and aromatic tings distribution of PAHs and the ratios of phenanthrene to anthracene and fluoranthene to pyrene suggested PAHs in sediments from Hetaidukou to Xinji was mainly derived from combustion and pyrolysis of fossil fuels in high temperature while that from Anhuai to Xiaohetou was mostly identified from incomplete combustion of fossil fuels in low and moderate temperature or diagenetic stage. Compared with the corresponding ecological risk assessment guidelines, Pingwei and Luohe sections will have potential ecological risks while others will be relatively low.