Effects of different variables on photodestruction of perfluorooctanoic acid in self-assembled micelle system
Effects of different variables on photodestruction of perfluorooctanoic acid in self-assembled micelle system
复制标题
不同变量对自组装胶束体系中全氟辛酸光破坏的影响
DOI：
10.1016/j.scitotenv.2020.140438
复制
发表时间：
2020
影响因子：
9.8
通讯作者：
Cheng Gu
中科院分区：
文献类型：
--
作者：
Zhanghao Chen;Na Mi;Chen Li;Ying Teng;Yi Chen;Cheng Gu
全氟烷基物质（PFAS）是一类在环境中具有上级稳定性的阴离子表面活性剂。由于PFASs对人体健康的危害，已被列为优先控制的污染物。本研究开发了一种阳离子表面活性剂诱导的三元自组装胶束体系，可有效降解PFASs。在这项研究中，使用全氟辛酸（PFOA）作为模型污染物，我们进一步研究了不同的变量对降解过程的影响。根据激光闪光光解和动态光散射的结果，PFOA的降解与表面活性剂的链长呈正相关。而对于双链表面活性剂，空间位阻效应会阻碍反应的进行。研究结果还表明，在高浓度NaCl存在下，Cl-与带正电的胶束之间的静电引力使胶束结构松散，从而略微降低了降解效率。同样，NOM的存在也可以通过调节胶束结构来影响降解过程。在中性pH条件下，通过平衡水合电子产率和自组装胶束结构，获得了最佳的PFOA降解效率。该复合材料在环境条件下显示出良好的适应性，并且将具有处理含PFAS的工业废水的巨大潜力，例如，在三元胶束体系中，18.95 mg L− 1 PFOA在8 h内可完全降解，无需任何预处理。
Perfluoroalkyl substance (PFAS) is a class of anionic surfactants with superior stability in the environment. Due to the harmful health effect, PFASs have been listed as the priority controlled pollutants. Our recent study had developed a cationic surfactant induced ternary self-assembled micelle system to effectively degrade PFASs. In this study, using perfluorooctanoic acid (PFOA) as the model pollutant, we further investigated the effects of different variables on the degradation processes. According to the results of laser flash photolysis and dynamic light scattering, the degradation of PFOA was positively correlated with the chain length of the surfactants. While for double-chain surfactant, the steric effect might hinder the reaction. Our results also indicated that in the presence of high concentration of NaCl, the electrostatic attraction between Cl−and the positively charged micelle made the micelle structure loose and thus slightly reduced the degradation efficiency. Similarly, the presence of NOM could also affect the degradation process via regulating the micelle structure. Furthermore, the optimal degradation efficiency for PFOA was obtained at neutral pH by the compromise of hydrated electron yield and self-assembled micelle structure. This composite showed good adaptability under ambient conditions and would have great potential for treatment of industrial PFAS containing wastewater, e.g., in the ternary micelle system, 18.95 mg L−1PFOA could be completely degraded within 8 h without any pretreatments.