The permanganate(Mn(Ⅶ))oxidation has emerged as a promising technology for the remediation and treatment of the groundwater and surface water contaminated with the organic compounds.Nonetheless,only a few studies have been conducted to explore the role of the heavy metals(especially the redox-active ones)during the Mn(Ⅶ)oxidation process.In this study,taking Pb(Ⅱ)as an example,its influence on the Mn(Ⅶ)decontamination performance has been extensively investigated.It was found that,with the presence of Pb(Ⅱ),Mn(Ⅶ)could degrade diclofenac(DCF),2,4-dichlorophenol,and aniline more effectively than without.For instance,over a wide pH range of 4.5-8.0,the dosing of 10 μmol/L Pb(Ⅱ)accelerated the DCF removal rate from 0.006-0.25 min-1 to 0.05-0.46 min-1 with a promotion factor of 1.9-9.4.Although the UV-vis spectroscopic and high resolution transmission electron microscopy analyses suggested that Mn(Ⅶ)could react with Pb(Ⅱ)to produce Mn(Ⅳ)and Pb(Ⅳ)at pH 6.0-8.0,further experiments revealed that Pb(Ⅱ)did not exert its enhancing effect through promoting the generation of MnO2,as the reactivity of MnO2 was poor under the employed pH range.At pH below 5.0,it was interesting to find that,a negligible amount of MMnO2 was formed in the Mn(Ⅶ)/Pb(Ⅱ)system in the absence of contaminants,while once MnO2 was generated in the presence of contaminants,it could catalyze the Pb(Ⅱ)oxidation to Pb(Ⅳ)by Mn(Ⅶ).Collectively,by highlighting the conversion process of Pb(Ⅱ)to Pb(Ⅳ)by either Mn(Ⅶ)or MnO2,the reactive Pb(Ⅲ)intermediates were proposed to account for the Pb(Ⅱ)enhancement effect.

Lei Dong;Pin Xie;Xin Zhang;Junlian Qiao;Dandan Rao;Yuankui Sun;Xiaohong Guan

College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;Shanghai Municipal Engineering Design Institute(group)Co.,Ltd.,Shanghai 200092,China;Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration,Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste,Institute of Eco-Chongming(IEC),School of Ecological and Environmental Science,East China Normal University,Shanghai 200241,China

环境科学与工程前沿

[1]Lei Dong;Pin Xie;Xin Zhang;Junlian Qiao;Dandan Rao;Yuankui Sun;Xiaohong Guan-.Co-present Pb(Ⅱ)accelerates the oxidation of organic contaminants by permanganate:Role of Pb(Ⅲ))[J].环境科学与工程前沿,2022(08):156-166

MMnO2

present,Pb,accelerates,oxidation,organic,contaminants,by,permanganate,Role,has,emerged,promising,technology,remediation,treatment,groundwater,surface,contaminated,compounds,Nonetheless,only,few,studies,have,been,conducted,explore,role,heavy,metals,especially,redox,ones,during,process,In,this,study,taking,example,its,influence,decontamination,performance,extensively,investigated,It,was,found,that,presence,could,degrade,diclofenac,DCF,dichlorophenol,aniline,more,effectively,than,without,For,instance,over,wide,range,dosing,accelerated,removal,from,promotion,Although,UV,vis,spectroscopic,resolution,transmission,electron,microscopy,analyses,suggested,produce,further,experiments,revealed,did,not,exert,enhancing,through,promoting,generation,reactivity,poor,under,employed,At,below,interesting,find,negligible,amount,formed,system,absence,while,once,generated,catalyze,Collectively,highlighting,conversion,either,reactive,intermediates,were,proposed,account,enhancement

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