紫外光致氯生水合电子对全氟辛酸的降解
发布时间：2018-10-19 15:41
【摘要】：研究了185 nm紫外光激发氯离子生成的水合电子还原降解全氟辛酸(PFOA)的效果.结果表明,该体系中氯离子、紫外光和绝氧环境是保证PFOA高效降解的必要条件;当PFOA的浓度为0.03 mmol/L时,最佳反应条件为氯离子与PFOA摩尔浓度比(cCl-/cPFOA)为10.0,溶液初始p H值为10.0,体系温度为25℃.该条件下反应23 h后PFOA的降解率和脱氟率分别达到99.6%和65.0%.PFOA在该体系中0~8 h的降解符合一级反应动力学,反应速率常数为6.3×10-3min-1.PFOA在该体系中降解的主要产物有氟离子、短链全氟羧酸、甲酸和乙酸.PFOA的降解有2种途径:(1)氯离子在紫外光照射下产生水合电子,水合电子进攻PFOA,造成C—F键及C—C键的断裂;(2)具有较高能量的185 nm紫外光光解PFOA,发生脱羧反应,并通过水解作用逐步脱氟.
[Abstract]:The degradation of perfluorooctanoic acid (PFOA) by hydrated electron reduction induced by chlorine ions under 185 nm UV irradiation was studied. The results show that chlorine ion, ultraviolet light and oxygen deprivation are the necessary conditions for the efficient degradation of PFOA, and when the concentration of PFOA is 0.03 mmol/L, The optimum reaction conditions are as follows: the molar concentration ratio of chloride to PFOA (cCl-/cPFOA) is 10.0, the initial pH value of solution is 10.0, and the temperature of the system is 25 鈩，
本文编号：2281571
[Abstract]:The degradation of perfluorooctanoic acid (PFOA) by hydrated electron reduction induced by chlorine ions under 185 nm UV irradiation was studied. The results show that chlorine ion, ultraviolet light and oxygen deprivation are the necessary conditions for the efficient degradation of PFOA, and when the concentration of PFOA is 0.03 mmol/L, The optimum reaction conditions are as follows: the molar concentration ratio of chloride to PFOA (cCl-/cPFOA) is 10.0, the initial pH value of solution is 10.0, and the temperature of the system is 25 鈩，
本文编号：2281571
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