电-Fenton及类电-Fenton技术处理水中有机污染物

Treatment of Organic Pollutants Using Electro-Fenton and Electro-Fenton-Like Process in Aqueous Solution

传统Fenton技术是一种广泛用于水体里有机污染物降解的高级氧化技术(advanced oxidation technologies,AOTs)。它利用Fenton试剂Fe2+与H2O2反应生成具有强氧化性的羟基自由基(·OH),从而降解有机污染物。基于相似的机理,过渡金属离子(Fe2+、Co2+和Ag+等)也可与过硫酸盐反应生成氧化能力较强的硫酸根自由基(SO4·-),而被称之为类Fenton技术。传统Fenton技术存在Fe2+投加量多,产生的铁污泥多等缺点,因此,有学者将Fenton技术与电化学技术结合,使Fe2+在阴极得以持续再生,这就是广为关注的电-Fenton技术。同样地,类Fenton技术也遇到与传统Fenton技术相似的问题。借鉴电-Fenton技术的成功应用,基于硫酸根自由基的类电-Fenton技术应运而生。本文在介绍电-Fenton和类电-Fenton技术原理的基础上,概括了电-Fenton和类电-Fenton技术的主要类型及其改进方法,并就值得深入研究的问题和热点趋势进行了展望。

Conventional Fenton process is one of the promising advanced oxidation technologies（ AOTs） for the treatment of organic pollutants in water. In Fenton process,hydroxyl radical（·OH）,a kind of strong oxidant,is formed through Fenton＇s reaction and then degrades organic pollutants. Similar to conventional Fenton process,transition metal ions（ Fe^2＋,Co^2＋,Ag^＋,etc.） can also activate persulfate（ PS） and generate sulfate radicals（ SO4^·-,SR）. Sulfate radical is a powerful oxidant and can oxidize most of organic pollutants. This process is named as ＂Fenton-like process＂. There are some disadvantages existed in conventional Fenton and Fenton-like process. For example,a high concentration of Fe^2＋ is required and a large amount of iron sludge is generated. In order to solve these problems,electro-Fenton and SR-based electro-Fenton-like processes are proposed. Fe^2＋ can be regenerated via cathodic reduction in electro-Fenton and electro-Fenton-like processes. Therefore,the Fe^2＋ concentration used in these processes is much lower than that in Fenton and Fenton-like processes. This paper provides an overviewof mechanism and research progress of electro-Fenton and SR-based electro-Fenton-like processes. The types and improvements for electro-Fenton and electro-Fenton-like processes are summarized.M oreover,the prospects of the research areas meriting further investigation and developed trends are pointed out.