| 高碘酸盐光化学降解水中PFOA研究 |
| 摘要点击 3685 全文点击 2749 投稿时间：2010-01-11 修订日期：2010-06-07 |
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| 中文关键词 PFOA 光化学降解 IO-4 反应气氛 PFCAs |
| 英文关键词 perfluorooctanoic acid（PFOA） photochemical decomposition IO-4 reaction atmosphere perfluorocarbonxylic acids(PFCAs) |
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| 中文摘要 |
| 研究了反应气氛和TiO2对全氟辛酸(PFOA)的光化学降解行为的影响. 结果表明，在254 nm紫外光照下，PFOA光解十分微弱，加入IO-4显著增强PFOA光解. 与氮气气氛相比，氧气气氛对PFOA光化学降解有抑制作用. PFOA在UV/TiO2/IO-4体系中的降解效果低于在UV/IO-4体系，反应120 min时，PFOA降解率为54%，降低了15%，这是由于均相反应和非均相反应发生竞争，光催化体系中产生的大量·OH消耗了IO-4，使得IO-4光解生成IO·3的反应受到抑制，从而抑制了PFOA的分解. HPLC/MS分析表明，PFOA光降解时逐级生成短链全氟羧酸（PFCAs）. |
| 英文摘要 |
| The influence of reaction atmosphere and TiO2 on photochemical decomposition of perfluorooctanoic acid(PFOA) in aqueous periodate was investigated using a type of low-pressure mercury lamps emitted at 254 nm. PFOA photolysis was slight with 254nm light irradiation under nitrogen, whereas significant decomposition PFOA obtained with the addition of IO-4. In addition, oxygen restrained photochemical decomposition of PFOA. In UV/TiO2/IO-4 system, PFOA degradation ratio was 54%, 15% lower than that for UV/IO-4 system. ·OH radicals generated from UV/TiO2 system exhausted a lot of IO-4, resulting in lower degree of IO·3 production. IO·3 was high reactive radical which great excitated PFOA decomposition. The accumulation of short-chain perfluorocarbonxylic acids(PFCAs) as products were identified with HPLC/MS. PFCAs bearing shorter perfluoroalkyl groups were formed in a stepwise way from PFCAs that bear longer perfluoroalkyl groups. |
