氟聚合物由于其出色的性能在多个领域有着重要应用，氟聚合物分散法聚合生产中需要使用非聚合全氟/多氟烷基化合物（PFAS）作为乳化剂，其中全氟辛酸（PFOA）曾被广泛使用。一系列研究表明PFOA暴露会对环境和生物造成威胁，多个国家地区相继管控PFOA，导致大量PFOA替代品问世。我国是氟聚合物生产大国，识别氟化工园区污水中PFAS污染特征是管控与治理PFAS的前提，但现有研究较为匮乏且存在较大的氟平衡缺口。本文以我国两个典型氟化工园区为代表，建立了以氟平衡为目标的PFAS综合分析方法来解析园区污水中PFAS污染特征，对比其中PFOA替代品的毒性，并评估现有污水处理工艺对PFAS的去除效果，为PFAS这类新污染物的筛查、替代与治理提供科学依据。首先，构建了以氟平衡为目标的PFAS综合分析方法，其中靶向分析实现了55种PFAS准确定量，非靶向分析利用本地化PFAS谱库提高了未知PFAS识别效率，基于紫外光活化过硫酸盐的总可氧化前体物分析缩短了方法操作时间，有机氟分析采用水合电子还原脱氟与离子色谱检测实现了总可还原有机氟定量分析。上述PFAS综合分析方法能够系统揭示氟化工园区污水及环境水体样品中PFAS污染特征，并能够解析84%–93%有机氟的化学结构。利用PFAS综合分析方法，对某中资氟化工企业园区和某外资氟化工企业集聚园区的污水进行解析。在两个氟化工园区污水中分别识别出83种和53种PFAS（置信度等级≥3c），其中36个PFAS结构首次在我国被报道。通过园区污水与企业车间废水的分析比对，确证了其中3种PFOA替代品成分（PFHxA、C7 HFPO-TA和6:2 FTCA）的排放企业。污水中PFAS浓度结果表明两个园区内主要使用的PFOA替代品为短链全氟羧酸（PFCA）、氢代PFCA和全氟醚羧酸。对比氟工业园相关文献中PFAS的识别特征后可以发现我国氟工业园的PFAS排放具有更替性和独特性，需要开展PFAS定期监测并制定针对我国PFAS特征的治理方案。基于斑马鱼肝脏细胞和斑马鱼胚胎评估PFOA及其8种替代品的毒性效应，发现我国企业特有替代成分（HFPO-TA和HFPO-TeA）的毒性要高于PFOA，并且对斑马鱼胚胎有显著发育毒性。通过对园区污水处理厂和园区尾水消纳人工湿地进行沿程监测，发现PFAS不能被有效去除，PFOA浓度甚至在出水中明显升高，该结果表明PFOA替代品的潜在风险值得关注，且现有污水处理工艺亟需改进。
Fluoropolymers have important applications in many fields due to their excellent properties. In the production of fluoropolymers, non-polymeric per/polyfluoroalkyl substances (PFAS) are required as emulsifiers, the most well-known of which is perfluorooctanoic acid (PFOA). Evidence has shown that exposure to PFOA can cause potential risks to the ecological environment and human health. Therefore, many countries and regions have successively regulated the production and use of PFOA, consequently resulting in PFOA alternatives emerging in the environment. As China is the major producer of fluoropolymers, identifying the characteristics of emerging PFAS is a prerequisite for PFAS risk assessment and governance. However, there is currently a lack of research on the identification of PFAS in fluorochemical industry park (FIP) wastewater and a significant gap in fluorine mass balance. In this study, two typical FIPs in China were selected as case studies to determine the profile and levels of PFAS. A comprehensive PFAS analysis strategy focused on fluorine mass balance was established to determine the characteristics of PFAS in FIP wastewater. In addition, the toxicity of emerging PFOA alternatives and the capacity of existing wastewater treatment facilities for PFAS removal are evaluated. Overall, this study strived to provide scientific strategies for the management of PFAS, which is an important class of Emerging Contaminants.Firstly, a comprehensive analysis strategy of PFAS with the aim of fluorine mass balance was established, in which the targeted analysis achieved an accurate quantification of 55 PFAS, the non-targeted analysis improved the identification efficiency of unknown PFAS by utilizing the personal chemical database and library of PFAS, the total oxidizable precursor assay reduced conversion time based on the UV light activation of persulfate, and the total reducible organic fluorine analysis method is based on the defluorination of PFAS by hydrated electrons. All the above methods are suitable for the analysis of PFAS in FIP wastewater. The application of this comprehensive analysis strategy revealed the characteristics of PFAS in FIP wastewater and explained 84%–93% organic fluorine. Based on the PFAS analytical methods, a systematic analysis was conducted on the wastewater collected from a northern FIP and a southern FIP in China, and 83 PFAS and 53 PFAS with confidence level ≥ 3c were identified in the wastewater of the two FIP wastewater treatment plant (WWTP), respectively. Among them, 36 emerging PFAS were first identified and reported in China FIP samples. Through the comparison of PFAS characteristics in FIP wastewater and factory wastewater, the source emission enterprises of three dominant PFAS (PFHxA, C7 HFPO-TA, and 6:2 FTCA) were confirmed for the first time. Via quantitative and semiquantitative analysis, it was observed that short-chain perfluorocarboxylic acid (PFCA), hydrogenated PFCA, and perfluoroether carboxylic acids (PFECA) were the main PFOA substitutes in the field of fluoropolymer production. By comparing the PFAS profile in wastewater collected at different times in the southern FIP, it was found that the PFAS profile in FIP wastewater was constantly changing. By comparing the characteristics of emerging PFAS identified in global FIP samples reported by literatures, it was found that the PFAS emission from Chinese FIPs are unique and variable. Thus, it is necessary to conduct regular PFAS monitoring and formulate a governance plan.The toxic effects of PFOA and its eight alternatives were evaluated based on the zebrafish liver cells and zebrafish embryos. The result showed that the toxicities of two emerging PFASs (HFPO-TA and HFPO-TeA) used by Chinese enterprises were higher than PFOA, and they showed significant developmental toxicity on zebrafish embryos. Taking the WWTP of two FIPs and a constructed wetland treating tail water from a FIP WWTP as cases, it was found that the current wastewater treatment processes cannot remove PFAS, moreover, the PFOA levels significantly increased in the effluent of WWTP and constructed wetland. Thus, there is an urgent need to regularly monitor PFAS emissions and to apply additional wastewater treatment for PFAS removal.
