环境因子对菲在黄河口沉积物上吸附的影响

Phenanthrene sorption by sediments from Yellow River Estuary: Effects of environmental factors

为研究多环芳烃从河口到近海的环境归趋行为与生态风险,考察了沉积物质量浓度、溶解性有机质、温度、盐度4种典型环境因子对菲在黄河口沉积物上吸附的影响,比较了黄河口与近海两种沉积物对菲的吸附性能。研究结果表明,沉积物质量浓度越低,单位质量颗粒物的菲吸附量越高;共存的溶解性有机质对菲的吸附具有增促作用,且腐殖酸比黄腐酸的作用更显著;温度的升高不利于菲的吸附,而盐度的增加有利于菲的吸附。菲在沉积物上的吸附是分配作用与表面吸附两种行为的耦合,其中黄河口沉积物以表面吸附为主,而近海沉积物以分配作用为主。近海沉积物菲吸附量显著高于黄河口沉积物菲吸附量。基于此,菲从河口到近海的迁移过程中,更易于在沉积物表面发生吸附沉降,从而可能降低水相中的生态危害,但对近海底栖生物具有潜在的健康生态风险。

To understand the environmental behaviors and ecological risks of polycyclic aromatic hydrocarbons （PAHs） in the transport processes from the river to the estuary, and subsequently coastal waters, the sorption of phenanthrene on the Yellow River estuary sediments was investigated under varying conditions including sediment concentrations, dissolved organic matter （DOM）, temperature, and salinity. Phenanthrene sorption by estuarine sediments and marine sediments were also compared. The results showed that sediments with low concentration exhibited high sorption capacity for phenanthrene. Phenanthrene sorption was enhanced in the presence of DOM, and the effect of humic acid （HA） was more significant than that of fulvic acid （FA）. The sorption capacity declined with increasing temperature, whereas it increased with increasing salinity. Surface adsorption and partitioning of phenanthrene occur simultaneously on the sediments. For estuarine sediments, adsorption was predominant, while partitioning was the main mechanism for marine sediments. Moreover, the sorption capacity of marine sediments was higher than that of estuarine sediments. Based on these results, it can be concluded that phenanthrene is in-clined to be adsorbed on sediments in the transport processes from the river to the estuary, and subsequently coastal waters, which may reduce the ecological damage in water, but raise the potential health risks to benthonic organ-isms in offshore marine areas.