银川市湖泊、河流沉积物中PAHs污染特征及风险评价

Pollution characteristics and risk assessment of PAHs in sediments of lakes and rivers in Yinchuan city

为了解银川市湖泊及城市河流沉积物中多环芳烃(PAHs)污染状况及生态风险,于2018年4～5月在银川市各湖泊及城市河流采集17个表层沉积物样品,采用气相色谱质谱(GC-MS)检测样品中PAHs含量.结果表明,银川市湖泊及城市河流表层沉积物中16种PAHs总含量范围为767.35～3961.53ng/g,平均值为2129.86ng/g,与国内外沉积物中PAHs污染状况相比,银川市湖泊及城市河流沉积物中PAHs污染处于较高水平.来源解析表明,银川市湖泊及城市河流沉积物中主要的污染来源为石油及煤炭等生物质的不完全燃烧.通过效应区间低中值法分析沉积物中PAHs的生态风险评价结果显示,部分采样点表层沉积物中菲的含量超过效应区间中值(ERM);沉积物质量标准法(SQSs)分析沉积物中PAHs生态风险结果表明,萘、苊检测含量在可能效应浓度值(PEL)与频繁效应浓度值(FEL)之间,菲的检测含量高于FEL;风险商值法分析显示苊烯、苊、菲、荧蒽风险熵值RQ>1.综合分析认为沉积物中多环芳烃的污染可能会造成一定程度的生态风险.

To understand the pollution status and ecological risk of polycyclic aromatic hydrocarbons(PAHs) in Yinchuan, a total of17 surface sediment samples were collected from lakes and urban rivers in Yinchuan City from April to May 2018. Gas chromatography-mass spectrometry(GC-MS) was used to detect the content of PAHs. The results showed that the total content of16 PAHs in sediment of lakes and urban rivers in Yinchuan City ranged between 767.35 and 3961.53 ng/g with an average of2129.86 ng/g. Compared with the pollution status of PAHs in sediments at home and abroad, the pollution status of PAHs in Yinchuan was at a high level. Source analysis showed that the main source of PAHs in sediments in Yinchuan City were incomplete combustion of petroleum and coal. The method of effects range low(ERL) and effects range median(ERM) were used to evaluate the ecological risk of PAHs in sediments. The result showed the content of Phe in surface sediments of some sampling points exceed ERM. Sediment Quality Standards(SQSs) showed the contents of Nap and Ace were between the possible effect level(PEL) and the frequent effect level(FEL), and the content of Phe was higher than FEL. Risk quotient analysis showed that the risk quotient(RQ)of Acy, Ace, Phe, and Fla were higher than 1.0. The pollution of PAHs in sample sediments may cause ecological risks.