海水中Cu2+和Cr3+对PFOS在沉积物上吸附行为的影响规律

为了解重金属与全氟辛烷磺酸(PFOS)共存情况下,PFOS在沉积物上的吸附规律,本研究分别测定了在海水和淡水条件下添加不同浓度的Cu2+和Cr3+(0.5~50 mM)后,PFOS在沉积物上的吸附行为。结果表明,随着Cu2+]的增加,PFOS在沉积物上的吸附能力和非线性均增强,且当溶液中PFOS浓度越低,增强作用越明显。与淡水相比,海水环境下该增强作用更为明显。随着Cr3+]的增加,PFOS在沉积物上的吸附能力和非线性略有增强,且海水和淡水环境中增强作用几乎相同。对比发现,海水中Cu2+对PFOS在沉积物上的吸附增强效应比Cr3+更加明显。本文研究结果将有助于定量了解和预测PFOS和重金属复合污染情况下,PFOS在海水环境中的迁移规律,并为科学评价海洋环境中PFOS和重金属的生态风险及其总量控制提供技术支撑。

Influence of copper and chromium to sorption of PFOS on marine sediment

Perfluorooctanesulfonate (PFOS) often co-existed with heavy metals in aquatic environment.To investigate influence of heavy metals on PFOS sorption,sorption isotherms of PFOS on sediment with different concentrations of Cu2+ and Cr3+ in seawater and freshwater were determined.The results showed that both of sorption capacity and nonlinearity of PFOS increased significantly with increasingCu2+],especially when the content of PFOS was at low level.This enhancing effect was more obviously in seawater.Moreover,the effect could also be found in ocean and freshwater system with increasingCr3+],but much weaker than that with increasingCu2+].The above results will provide data to predict and model the transport,distribution and fate of PFOS,and will be helpful for evaluating the ecological risk of PFOS and heavy metals in ocean.