A Study On Pollution Characteristics, Ecological Risk Assessment And Management Strategies Of PFASs In The Jiulong Estuary-Xiamen Bay

Per-and polyfluoroalkyl compounds(PFASs)is a new type of persistent organic pollutants(POPs)closely concerned by the world.Because of their chemical stability with hydrophobic and oleophobic properties,they have been widely used in industrial production and necessities in daily life.A large number of toxicological studies have proved that PFASs may cause damage to the liver,nervous tissue,reproductive and immune system of human beings and organisms to a certain degree.As global distributed pollutants,they have been detected in various media in many countries.China is one of the major producers of PFASs,where current domestic researches on PFASs mainly focus on testing methods and the investigation of pollution occurrence,but lack of regional systematic research at present.Since Jiulong Estuary-Xiamen Bay is an important water source in the Xiamen area,this study combines PFASs pollution characteristics,ecological risk assessment and hydrological model to conduct systematic research on it from multiple dimensions and perspectives.Based on the results above,pollution preventing measures and environmental management strategies are given.The preliminary conclusions are as follows:1)The concentration range of 28 kinds of PFASs was 0.34-100.33 ng L-1 in the waters of the Jiulong Estuary-Xiamen Bay including 13 perfluorinated carboxylic acids(PFCAs),5 perfluorinated sulfonic acid(PFSAs),and 10 precursors,expressing a significant seasonal variation.The PFASs of the surface water in the dry season(12.94-100.33 ng L-1)was much higher than those(0.41-5.88 ng L-1)in the wet season.PFOS was the main medium-chain PFASs,PFBS was the main pollutant of PFSAs,and PFBA,PFPeA,PFHxA were dominant in PFCAs.Judging from the spatial distribution,the Jiulong estuary,Gulangyu Island,Maluan Bay and Tong'an Bay were highly polluted.From the point of view on occurrence in China,the PFASs in the Jiulong Estuary-Xiamen Bay were generally at a moderate level.2)The PFASs in the sediments of the Jiulong Estuary-Xiamen Bay was 4.64-7.42 ng g-1 dw.PFOS was the main pollutant.The adsorption ability of sediment increased as the carbon chain and salinity increased according to the sediment-water partition coefficient.3)Using AIST-MeRAM model to assess the ecological impact of PFASs in the Jiulong Estuary-Xiamen Bay,and the results showed that PFASs constituted no ecological threats to the research area so far,measured by the Margin of Exposure(MOE)indicator and Species Sensitivity Distribution method(SSD).4)Through the simulation of the physical parameters of the Jiulong Estuary-Xiamen Bay,the thermohaline and flow distributions were all reflected on the spatial scales.The simulated results showed that there were long water cycles and with weak self-purification capabilities in the West Bay of Xiamen and shallow waters like Maluan Bay and Tong'an Bay,which may be prone to environmental problems.Thus,environmental management measures for district prevention and control were given.