Research Center for Environmental Pollution Prevention and Control Technology, Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Rd., Taipei 106, Taiwan, ROC.
J Hazard Mater. 2013 Oct 15;261:463-9. doi: 10.1016/j.jhazmat.2013.07.054. Epub 2013 Aug 8.
Treatment of persistent perfluorooctanoic acid (PFOA) in water using persulfate (PS) oxidation typically requires an elevated temperature or UV irradiation, which is energy-consuming. Under relatively low temperatures of 25-45°C, activated carbon (AC) activated PS oxidation of PFOA was evaluated for its potential of practical applications. With presence of AC in PS oxidation, PFOA removal efficiency at 25°C reached 682% with a high defluorination efficiency of 549% after 12h and few intermediates of short-chain perfluorinated carboxylic acids (PFCAs) were found. The removal and defluorination rates with the combined AC/PS system were approximately 12 and 19 times higher than those of the PS-only system, respectively. Activated carbon not only removes PFOA through adsorption, but also activates PS to form sulfate radicals that accelerate the decomposition and mineralization of PFOA. The activation energy for PS oxidation of PFOA was reduced from 668 to 261kJ/mol by the catalytic effect of AC, which implies a lower reaction temperature and a shorter reaction time would suffice. A 2-cycle schematic reaction mechanism was used to describe PS oxidation of PFOA with the generation of various intermediates and end-products.
过硫酸盐（PS）氧化法处理水中持久性全氟辛酸（PFOA）通常需要高温或紫外线照射，这是耗能的。在相对较低的温度 25-45°C 下，评估了活性炭（AC）激活 PS 氧化 PFOA 的潜在实际应用。在 PS 氧化中存在 AC 的情况下，在 25°C 下，PFOA 的去除效率达到 682%，12 小时后高脱氟效率达到 549%，且发现很少有短链全氟羧酸（PFCAs）中间体。组合 AC/PS 系统的去除和脱氟速率分别比 PS 单独系统高约 12 倍和 19 倍。活性炭不仅通过吸附去除 PFOA，还能激活 PS 形成硫酸根自由基，从而加速 PFOA 的分解和矿化。活性炭的催化作用将 PS 氧化 PFOA 的活化能从 668kJ/mol 降低至 261kJ/mol，这意味着更低的反应温度和更短的反应时间就足够了。使用 2 个循环示意反应机制来描述 PS 氧化 PFOA 与各种中间产物和最终产物的生成。
