【摘要】：研究了185 nm紫外光激發(fā)氯離子生成的水合電子還原降解全氟辛酸(PFOA)的效果.結(jié)果表明,該體系中氯離子、紫外光和絕氧環(huán)境是保證PFOA高效降解的必要條件;當(dāng)PFOA的濃度為0.03 mmol/L時,最佳反應(yīng)條件為氯離子與PFOA摩爾濃度比(cCl-/cPFOA)為10.0,溶液初始p H值為10.0,體系溫度為25℃.該條件下反應(yīng)23 h后PFOA的降解率和脫氟率分別達到99.6%和65.0%.PFOA在該體系中0~8 h的降解符合一級反應(yīng)動力學(xué),反應(yīng)速率常數(shù)為6.3×10-3min-1.PFOA在該體系中降解的主要產(chǎn)物有氟離子、短鏈全氟羧酸、甲酸和乙酸.PFOA的降解有2種途徑:(1)氯離子在紫外光照射下產(chǎn)生水合電子,水合電子進攻PFOA,造成C—F鍵及C—C鍵的斷裂;(2)具有較高能量的185 nm紫外光光解PFOA,發(fā)生脫羧反應(yīng),并通過水解作用逐步脫氟.
[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，

本文編號：2281571