珠江广州段水体中全/多氟烷基化合物的空间和季节分布特征

Spatial and Seasonal Distribution Characteristics of Per-and Poly⁃fluoroalkyl Substances in Water from the Guangzhou Reach of the Pearl River,China

全/多氟烷基化合物(PFASs)普遍存在于各环境介质中,因具有生物累积性、持久性和潜在毒性,已成为全球最受关注的新污染物之一。城市河流污染来源复杂,受周边功能区和季节影响大,PFASs等新污染物的河流污染特征仍需进一步研究。该文选择珠江广州段为研究区域,在2020年7月采集40个水样,探讨水相样品中16种PFASs的空间分布和季节差异特征。珠江广州段水体中PFASs的总浓度为(77.7±38.3) ng/L(17.9~164 ng/L),干流中PFASs的浓度普遍高于支流,且浓度从城市附近的中上游到接近河口的下游大幅降低。雨季水体中PFASs的浓度较旱季显著降低,其组成也有一定变化,全氟辛酸(PFOA)在旱季和雨季中均占比最大,但雨季中全氟丁烷磺酸(PFBS)、全氟辛烷磺酸(PFOS)、全氟己酸(PFHxA)占比增加,PFOA和全氟丁酸(PFBA)占比减少,短链PFASs占比略有上升,70%的采样点短链PFASs在雨季的占比高于旱季。该研究为评估环境水体中PFASs污染提供了基础数据。

Per-and polyfluoroalkyl substances(PFASs)are ubiquitous in various environmental me⁃dia and have become one of the most concerning new pollutants globally due to their bioaccumulation,persistence and potential toxicity.The pollution status in urban rivers is complex in sources and great⁃ly influenced by the surrounding functional zones and seasons.Therefore,the pollution characteris⁃tics of new pollutants such as PFASs require further investigation.This study selected the Guangzhou section of the Pearl River as the study area and investigated the spatial distribution and seasonal varia⁃tions of 16 PFASs in water samples collected in July 2020.The total concentrations of PFASs in water of the Guangzhou reach of the Pearl River were(77.7±38.3)ng/L(17.9-164 ng/L).The concen⁃trations of PFASs in the main stream were higher than those in the tributaries,and the concentrations significantly decreased from the middle and upper sections near the city to the lower sections near the estuary.The concentrations of PFASs in the rainy season were significantly lower than those in the dry season,and the compositions also changed to some extent.Perfluorooctanoic acid(PFOA)ac⁃counted for the largest proportion in both the dry and rainy seasons,but the proportions of perfluoro⁃butane sulfonic acid(PFBS),perfluorooctane sulfonic acid(PFOS),and perfluorohexanoic acid(PF⁃HxA)increased in the rainy season,while the proportions of PFOA and perfluorobutanoic acid(PF⁃BA)decreased.The proportions of short-chain PFASs increased slightly,and the proportions of short-chain PFASs in water from the 70%of the sampling sites were higher in the rainy season than in the dry season.This study provides fundamental data for assessing PFASs pollution in the aquatic en⁃vironment.