Decomposition of environmentally persistent perfluorooctanoic acid in water by photochemical approaches
Decomposition of environmentally persistent perfluorooctanoic acid in water by photochemical approaches
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DOI：
10.1021/es049719n
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发表时间：
2004-11-15
影响因子：
11.4
通讯作者：
Arakawa, R
中科院分区：
文献类型：
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作者：
Hori, H;Hayakawa, E;Arakawa, R
通过紫外-可见光照射、紫外-可见光照射下的 H2O2 以及钨杂多酸光催化剂对水中持久性和生物累积性全氟辛酸 (PFOA) 的分解进行了研究，以开发一种抵消固定源 PFOA 的技术。直接光解缓慢进行，产生CO2、F-和短链全氟羧酸。与直接光解相比，H2O2 对 PFOA 的分解效果较差。另一方面，杂多酸光催化剂导致PFOA的有效分解并产生F-离子和CO2。光催化剂还抑制了反应溶液中短链全氟羧酸的积累。浓度为 0.34-3.35 mM 的 PFOA（含氟聚合物制造中乳化过程后废水中的典型浓度）在 200 W 氙汞灯照射下 24 小时内被催化剂完全分解，没有伴随的催化剂降解，从而允许催化剂在连续运行中重复使用。气相色谱/质谱 (GC/MS) 测量结果显示，没有发现对环境不利的物质，例如具有极高全球变暖潜力的 CF4。当（初始PFOA）/（初始催化剂）摩尔比为10:1时，照射24小时后PFOA分解周转数达到4.33。
The decomposition of persistent and bioaccumulative perfluorooctanoic acid (PFOA) in water by UV-visible light irradiation, by H2O2 with UV-visible light irradiation, and by a tungstic heteropolyacid photocatalyst was examined to develop a technique to counteract stationary sources of PFOA. Direct photolysis proceeded slowly to produce CO2, F-, and short-chain perfluorocarboxylic acids. Compared to the direct photolysis, H2O2 was less effective in PFOA decomposition. On the other hand, the heteropolyacid photocatalyst led to efficient PFOA decomposition and the production of F- ions and CO2. The photocatalyst also suppressed the accumulation of short-chain perfluorocarboxylic acids in the reaction solution. PFOA in the concentrations of 0.34-3.35 mM, typical of those in wastewaters after an emulsifying process in fluoropolymer manufacture, was completely decomposed by the catalyst within 24 h of irradiation from a 200-W xenon-mercury lamp, with no accompanying catalyst degradation, permitting the catalyst to be reused in consecutive runs. Gas chromatography/mass spectrometry (GC/MS) measurements showed no trace of environmentally undesirable species such as CF4, which has a very high global-warming potential. When the (initial PFOA)/(initial catalyst) molar ratio was 10: 1, the turnover number for PFOA decomposition reached 4.33 over 24 h of irradiation.