摘要
高铁酸盐〔Fe(Ⅵ)〕是一种环境友好型水处理剂,可以有效氧化具有不饱和官能团的有机污染物,但Fe(Ⅵ)直接氧化法具有诸多缺点亟待改善,如Fe(Ⅵ)在酸性条件下易于自分解、在碱性条件下反应速率低等.开发Fe(Ⅵ)氧化的强化技术可以通过生成高活性的高价铁氧中间体〔Fe(Ⅳ)/Fe(Ⅴ)〕或活性自由基,提高有机污染物的去除效能.本文系统介绍了多种Fe(Ⅵ)氧化的强化技术去除有机污染物的效能、活性物种和机理.Fe(Ⅵ)可以被酸、还原剂等均相活化剂和二氧化硅、过氧化钙、碳质材料等异相活化剂活化为Fe(Ⅳ)/Fe(Ⅴ)以促进有机污染物的降解,也可以与氧化剂、含硫还原剂、紫外光、光催化体系联用,通过产生活性自由基等活性物种〔如羟基自由基((•)^OH)、硫酸根自由基(SO_(4)^(•−))、超氧自由基(O_(2)^(•−))等〕协同降解有机污染物.由于活性物种发生变化,Fe(Ⅵ)氧化的强化技术可以影响有机污染物降解产物的种类、分布及毒性.目前的研究仍存在一些不足,如多种Fe(Ⅵ)氧化的强化技术机理尚不明确或存在争议,Fe(Ⅵ)氧化的强化技术导致的有机污染物降解产物变化相关研究较少,对Fe(Ⅵ)氧化的强化技术在实际水体中的降解效能也兹待研究.此外,有必要进一步开发高效环保的Fe(Ⅵ)氧化的强化技术.
Ferrate(Fe(Ⅵ))is an environmentally friendly water treatment agent that can effectively oxidize organic pollutants with unsaturated functional groups.However,direct oxidation of organic pollutants by Fe(Ⅵ)bears many limitations,such as rapid self-decomposition of Fe(Ⅵ)under acidic conditions,low reactivity under alkaline conditions,et al.Developing enhanced Fe(Ⅵ)oxidation technologies(including Fe(Ⅵ)activation and synergy technologies)can improve the performance of Fe(Ⅵ)oxidation through generating highly active high-valent iron oxide intermediates(Fe(Ⅳ)/Fe(Ⅴ))or active free radicals.This paper systematically introduces the efficiencies,active species,and mechanisms of various enhanced Fe(Ⅵ)oxidation technologies for removing organic pollutants.Fe(Ⅵ)can be activated by homogeneous activators such as acids,reducing agents,and heterogeneous activators such as silica,calcium peroxide,and carbonaceous materials to produce Fe(Ⅳ)/Fe(Ⅴ),thus promoting the degradation of organic pollutants.Fe(Ⅵ)can also be used in combination with oxidants,sulfur-containing reducing agents,ultraviolet light,and photocatalytic system to generate active species such as active free radicals(hydroxyl radicals((•)^OH),sulfate radicals(SO_(4)^(•−)),and superoxide radicals(O_(2)^(•−)),thus degrading organic pollutants synergistically.Due to the change of active species,the enhanced Fe(Ⅵ)oxidation technologies can affect the types,distribution,and toxicity of organic pollutant degradation products.There are still some deficiencies in the current studies.For example,the mechanisms of various Fe(Ⅵ)oxidation enhanced technologies are still unclear or controversial,and there are few studies on the changes of the degradation products of organic pollutants caused by the enhanced Fe(Ⅵ)oxidation technologies.The degradation efficiency of the enhanced Fe(Ⅵ)oxidation technologies in real water remains to be studied.In addition,it is necessary to further develop efficient and environmentally friendly enhanced Fe(Ⅵ)oxidation technologies.
作者
李宇
程和发
LI Yu;CHENG Hefa(Laboratory for Earth Surface Processes,Ministry of Education,College of Urban and Environmental Sciences,Peking University,Beijing 100871,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2022年第6期1323-1333,共11页
Research of Environmental Sciences
基金
国家杰出青年科学基金项目(No.41725015)
国家自然科学基金项目(No.U2006212)。
关键词
有机污染物
高铁酸盐
活化技术
协同技术
降解产物
毒性
organic pollutant
ferrate
activation technology
synergy technology
degradation product
toxicity
作者简介
李宇(1995-),男,辽宁大连人,Li-Yu@pku.edu.cn;责任作者,程和发(1976-),男,山东济南人,教授,博士,博导,主要从事环境地球化学研究,hefac@pku.edu.cn。
