闽江福州段沉积物中多环芳烃的分布、来源及其生态风险

Distribution, sources and ecological risks of PAHs in sediment of Minjiang River in Fuzhou City

对闽江福州段37个沉积物样品中的15种多环芳烃(PAHs)进行了研究.结果表明,15种PAHs的总量在241.5～1310.8ng·g-1之间,均值为630.9ng·g-1,且从上游到下游整体上呈下降的趋势,但在福州市区附近有突增的现象.沉积物中有机质含量(SOM)与PAHs总量呈显著正相关(r=0.58,p<0.01).同时,应用因子分析和多元线性回归方法对PAHs进行了源解析.结果表明,煤燃烧来源占31.7%,汽油燃烧占25.2%,柴油燃烧占28.7%,石油泄漏源占14.5%,石油燃烧是闽江福州段沉积物中PAHs的主要来源.用效应区间中值ERM(the effects range median)和效应区间低值ERL(the effects range low)及其商值平均方法对闽江福州段沉积物中PAHs的生态风险进行了评价.结果表明,有4个样品芴的含量超过ERL指导值(19ng·g-1),具有一定的生态风险,其余PAH单体和PAHs总量都不超标.

Fifteen PAHs in 37 surface sediment samples collected from Minjiang River in Fuzhou City were studied, The results showed that the total concentrations of 15 PAHs ranged from 241.5 ng, g^-1 to 1310, 8 ng, g^-1 and the average was 630.9 ng, g^-1 The concentration of total PAHs in sediments showed an obviously decreasing trend from upstream to downstream, with a sudden surge near the Fuzhou City. There was a significant positive correlation between organic matter content and total PAH concentration in sediment samples （ r = 0.58, p 〈 0.01 ）. Factor analysis and multiple linearregression analysis showed that the major sources of PAHs in sediments were coal combustion （31. 7% ） , diesel combustion （28. 7% ）, gasoline combustion （25.2%） and petroleum leakage （ 14.5% ）. Petroleum combustion was the main source of PAHs in the sediments of Minjiang River in Fuzhou City. The ecological risk of PAHs was evaluated by the effects range median values （ERM） , the effects range low values （ERL） and ERL average quotient. The results indicated that the concentration of Fluorene exceeded the guideline value （19 ng.g^-1 ） in four sediment samples from Fuzhou reach of Minjiang River, implying certain ecological risks in these samples. The ERL values of other PAH isomers and total PAHs in all sediment samples were lower than the ERL guideline value.