Is addition of reductive metals (Mo, W) a panacea for accelerating transition metals-mediated peroxymonosulfate activation?

Bo Sheng; Xin Zhou; Zhun Shi; Zhaohui Wang; Yaoguang Guo; Xiaoyi Lou; Jianshe Liu

doi:10.1016/j.jhazmat.2019.121877

Is addition of reductive metals (Mo, W) a panacea for accelerating transition metals-mediated peroxymonosulfate activation?

J Hazard Mater. 2020 Mar 15:386:121877. doi: 10.1016/j.jhazmat.2019.121877. Epub 2019 Dec 16.

Authors

Bo Sheng¹, Xin Zhou², Zhun Shi², Zhaohui Wang³, Yaoguang Guo⁴, Xiaoyi Lou⁵, Jianshe Liu⁶

Affiliations

¹ Research Center of Resource Recycling Science and Engineering, School of Environmental and Materials Engineering, Shanghai Polytechnic University, Shanghai 201209, China; State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
² State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
³ Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Institute of Eco-Chongming (IEC), No.20 Cuiniao Road, Chen Jiazhen, Shanghai 202162, China. Electronic address: zhwang@des.ecnu.edu.cn.
⁴ Research Center of Resource Recycling Science and Engineering, School of Environmental and Materials Engineering, Shanghai Polytechnic University, Shanghai 201209, China. Electronic address: ygguo@sspu.edu.cn.
⁵ Key Laboratory of Control of Quality and Safety for Aquatic Products, Ministry of Agriculture, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China.
⁶ State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.

PMID: 31884370
DOI: 10.1016/j.jhazmat.2019.121877

Abstract

The interaction of reductive metal ions and peroxymonosulfate (PMS) is necessary for the generation of sulfate radials (SO₄^-), however, this process is greatly restrained by the sluggish reduction of high-valent metal ions. Here we report that commercially available reductive metal (Mo or W) powders are capable of unlocking this kinetic constraint. The reduction of Fe(III) to Fe(II), decomposition of PMS, and degradation/mineralization of 4-chlorophenol (4-CP) are all accelerated in the Mo/Fe²⁺/PMS process at a very low Fe²⁺/PMS ratio (Fe²⁺/PMS = 1/10). In such an accelerated system, common adverse effects of natural water constituents such as chloride and humic acid are largely mitigated. According to the fluorescence measurement and scavenging tests, sulfate and hydroxyl radicals dominate in Mo/Fe²⁺/PMS process. The addition of Mo or W is further confirmed to favor Cu²⁺/PMS process, but this is not the case for other metal ions (Mn²⁺, Ni²⁺, Ce³⁺ and Co²⁺). Reductive zero-valence and four-valence active sites (Mo⁰ and Mo⁴⁺; W⁰ and W⁴⁺) play key roles in overall redox reaction. Overall, our present work provides an alternative route for expediting redox cycling of transition metals in advanced oxidation processes, without useless consumption of PMS and increase of total organic carbon.

Keywords: Molybdenum; Peroxymonosulfate; Redox cycling; Sulfate radical; Transition metal ions.

Publication types

Research Support, Non-U.S. Gov't