太湖表层沉积物中PAHs的空间分布及风险评价

Spatial Distribution and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Partial Surface Sediments of Taihu Lake

采用GC-MS方法测定了太湖湖区20个典型采样点表层沉积物中的多环芳烃(PAHs)含量,共检出13种PAHs,其浓度〔w(ΣPAHs)〕范围为422.3～2 001.1μg/kg.其中,属于我国优先控制的污染物有5种,属于US EPA(美国国家环境保护局)优先控制的污染物有11种,w(ΣPAHs)为277.5～1 756.8μg/kg,最高浓度出现在太湖梅梁湾区域,PAHs在湖区总体的空间分布趋势呈梅梁湾>南部区>东部区>湖心区.风险评价结果表明,针对检测出的11种US EPA优先控制的PAHs,除了某些采样点的芴(Flu)浓度处于中度潜在风险水平外,其余10种PAHs尚未对水环境造成明显危害风险影响.利用特征化合物指数法对PAHs进行源分析发现,其主要来源是燃料燃烧.

The amounts of polycyclic aromatic hydrocarbons（PAHs） from 20 typical surface sediment sites in Taihu Lake were tested by GC-MS.Concentrations of the 13 detected PAHs compounds ranged from 422.3 to 2001.1 μgkg,among which five PAHs were identified by China as priority pollutants,while 11 PAHs were identified by the US EPA as priority pollutants,and the range of PAHs wass 277.5-1 756.8 μgkg,the highest concentration was found in Meiliang Bay area.PAHs in the lake district showed a general spatial distribution trend as follows：Meiliang Lake Southern district Eastern district Central district.Risk evaluation suggested that the 11 PAHs identified as priority pollutants by the US EPA have not shown obvious harm to the water environment,with the exception of Flu,which showed a moderate potential risk level at some sites.The characteristic compound index method indicated that fuel combustion was the main source of PAHs in Taihu Lake.