摘要
近年来,基于硫酸根自由基(SO_(4)·^(-))的新型高级氧化技术研发及其在水污染控制和土壤修复方面的应用备受关注.锰基氧化物因其结构性质多变、自然丰度高、环境友好等优势,被广泛应用于活化过氧一硫酸盐(PMS)和过氧二硫酸盐(PDS)处理难降解有机污染物.该文对可活化PMS PDS的锰基氧化物的类型、结构特征、合成方法及影响反应活性的因素等进行了介绍,重点对不同锰基催化剂活化PMS PDS的反应机理进行了讨论,并对未来的研究和发展进行了展望,旨在为拓展锰基矿物材料环境应用和阐明过硫酸盐活化机制提供重要参考.结果表明:活化产生的SO_(4)·^(-)和羟基自由基(·OH)对污染物的降解起关键作用.SO_(4)·^(-)具有较高的稳定性和氧化性,在降解过程中发挥主导作用.复合型锰基氧化物相较于单一锰基氧化物表现出更优的催化反应活性.PMS和PDS活化的反应机理存在显著差异:前者通过Mn(Ⅳ)与Mn(Ⅲ)之间的氧化还原循环,先生成SO_(5)·^(-)再产生SO_(4)·^(-),而后者是通过氧化还原反应相继生成S_(2)O_(8)·^(-)及SO_(4)·^(-).此外,MnO_(2)活化PDS还存在仅生成单态氧的非自由基反应机理.现阶段锰基氧化物活化PDS的相关研究仍比较匮乏,值得未来进一步深入研究.锰基材料活化PDS PMS产生的活泼中间体Mn(Ⅲ)的鉴定及对污染物降解的贡献仍需更多直接的试验证据.
In recent years,development of novel sulfate radical-based advanced oxidation processes and their application in water pollution control and soil remediation have attracted much attention.Mn-based oxides are widely used as an effective catalyst for the degradation of organic contaminants by activation of peroxymonosulfate(PMS)and peroxydisulfate(PDS)due to their structural diversity,natural abundance,environmental friendliness and other advantages.This review comprehensively elucidates the types,structural characteristics,synthesis methods and factors affecting reactivity of various Mn-based materials which are used to activate PMS PDS,with a special focus on the activation mechanisms of various Mn-based catalysts.The future research and development on this topic are prospected,aiming to provide an important reference for expanding the environmental application of manganese-based mineral materials and elucidating the activation mechanism of persulfate.It is found that the sulfate radicals and hydroxyl radicals produced by activation play a key role in the degradation of pollutants.In particular,sulfate radicals have high stability and oxidability,and play a leading role in the degradation process.The composite Mn-based oxide exhibits better catalytic reaction activity than a single Mn-based oxide.There are different reaction mechanisms for MnO_(2) to activate PMS and PDS.The former generates SO_(5)·^(-)and SO_(4)·^(-) through redox reactions between Mn(Ⅳ)and Mn(Ⅲ),while the latter generates S_(2)O_(8)·^(-) and SO_(4)·^(-).In addition,MnO_(2) activated PDS also has a non-radical reaction mechanism that only generates singlet oxygen.At present,the related research on PDS activation by Mn-based oxides is still scarce,deserving further investigations in future.More direct experimental evidence is needed for the identification of the active intermediate Mn(Ⅲ)produced by Mn-based materials activated PDS PMS and evaluation of its contribution to the degradation of pollutants.
作者
王一凡
李小蝶
侯美茹
王兆慧
WANG Yifan;LI Xiaodie;HOU Meiru;WANG Zhaohui(Shanghai Key Laboratory for Urban Ecological Process and Eco-Restoration,East China Normal University,School of Ecological and Environmental Sciences,Shanghai 200241,China;Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste,Shanghai 200241,China;Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area,Ministry of Natural Resources,Shanghai 200062,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2021年第8期1899-1908,共10页
Research of Environmental Sciences
基金
国家自然科学基金项目(No.21677031)
上海市科委“科技创新行动计划”“一带一路”青年科学家交流项目(No.19230742800)。
