渤海水体中全氟化合物的总量、输入通量和来源研究

Due to the persisitent, bioaccumulative, and toxic characteristics of perfluorinated compounds (PFCs), perfluorooctane sulfonate and its salts were listed in the Stockholm Convention on persistent organic compounds. Because of its relatively high water-solubility, aquatic systems are regraded as a major sink and the most important medium for PFC transport in the environment. Monitoring of PFCs in seawater results showed that concentrations of PFCs in water from Bohai Sea were significantly higher that those in other areas. Additionally, PFCs concentrations in the effluent from wastewater treatment plants were much higher than those in receiving seawaters. Therefore, effluents may be considered as one of the reason for the higher level of PFCs in Bohai Sea. It is crucial to quantify the level, flux and input sources of PFCs in Bohai Sea. To this end, we plan to investigate concentrations and compositions of PFCs in seawater and potential sources (sewage outlets, rivers, rain and dry deposition) at high temporal resolution at multiple locations within Bohai Sea area. Comparions of levels and compositions of PFCs were made between seawater samples and input samples. Besides, we assessed the main sources of PFCs in seawater and composition characteristics of PFCs in different sources. This project will better understand the different emission processes of PFCs to the environment and source apportionment for PFCs. These results will also be useful for the ecological risk assessment, relative standard establishment and management of PFCs.

全氟化合物（PFCs）作为一类新型的POPs，具有较好的水溶性，因此水体被认为是其重要的环境介质和主要的汇。监测结果显示，我国渤海海域水体中PFCs含量较国内外其他海域要高，同时我国城镇污水处理厂出水中PFCs的含量较海洋水体中最高达5个数量级，这可能是海洋环境中PFCs含量较高的原因之一。为全面定量了解目前我国渤海水体中PFCs的污染现状和来源，本项目拟以渤海水体为研究介质，定量研究渤海水体以及各污染源（排污口、河流、雨水和大气干沉降）中PFCs含量和组成分布特征，及其时空变化规律，并通过渤海水体和污染源、不同季节和不同区域的污染源中PFCs含量和组成的对比，分析进入渤海水体PFCs的主要途径和各污染源PFCs组成的特征。此项工作对PFCs的源解析研究具有重要的科学意义，并为我国海洋环境中PFCs的生态风险评价、相关质量和排放标准制定以及污染防治等工作提供基础数据和科学依据。

 根据项目申请书的相关要求，开展了下列工作：. 1、我国渤海海水、沉积物和入海污水中的全氟化合物（PFASs）时空分布特征.在中国的渤海海域采集海水和沉积物，研究结果表明，在海水和沉积物样品中总PFASs的浓度为（99.4ng/L，0.33—2.78ng/L）。其中，PFOA是PFASs在海水和沉积物中的主要存在形式，在七月采集的样本中沉积物浓度的中值是0.24ng/L,海水中的中值是4.97ng/L。海水中PFASs受季节性的周期变化的影响，而在沉积物并不存在。入海河流和排污口中分析结果显示PFASs值103ng/L-443ng/L，是渤海海域海水值的四倍，因此该排放对渤海海域PFASs的污染具有一定的贡献。..2、中国氟工业园区富集的辽东湾流域PFASs的赋存、来源与入海通量估算. 在包含两个氟工业园区的辽东湾流域35个河水样品和34个沉积样品中，研究了18种不同的PFASs。其中，全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）是淡水中主要的PFASs，平均浓度分别为26.5 ng / L和1.87 ng / L。然而，全氟丁烷磺酸（PFBS）在最接近PFAS工业来源的位置在水中具有最高的最大浓度（高达124.1ng / L，大约两个数量级）。在这个位置的水中总PFASs也是最高的。相比之下，PFOA和全氟十八烷酸（PFOcDA）是沉积物中最丰富的PFASs，平均浓度分别为1.19 ng / g和0.35 ng / g。来自工业园区附近的泥沙中的总PFASs浓度明显高于其他河流。据估算，辽东湾河流总PFASs的输入通量为506kg /y。