Synergetic activation of peroxymonosulfate by MnO2-loaded β-FeOOH catalyst for enhanced degradation of organic pollutant in water

Cong Lyu; Dan He; Zishen Mou; Xuejiao Yang

doi:10.1016/j.scitotenv.2019.133589

Synergetic activation of peroxymonosulfate by MnO₂-loaded β-FeOOH catalyst for enhanced degradation of organic pollutant in water

Sci Total Environ. 2019 Nov 25:693:133589. doi: 10.1016/j.scitotenv.2019.133589. Epub 2019 Jul 29.

Authors

Cong Lyu¹, Dan He², Zishen Mou³, Xuejiao Yang²

Affiliations

¹ Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130026, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130026, PR China. Electronic address: lvcong@jlu.edu.cn.
² Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130026, PR China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130026, PR China.
³ State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, PR China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil and Water Pollution, Chengdu University of Technology, Chengdu 610059, PR China.

PMID: 31635017
DOI: 10.1016/j.scitotenv.2019.133589

Abstract

In this paper, manganese dioxide (MnO₂) loaded iron oxyhydroxide (β-FeOOH) was synthesized aiming to improve the catalytic performance of β-FeOOH as peroxymonosulfate activator. The β-FeOOH@MnO₂/PMS system exhibited excellent performance and its reaction rate constant of Acid Orange 7 (AO7) degradation (0.0533 min^-1) was approximately 2.3 times as that in β-FeOOH/PMS system (0.0232 min^-1). β-FeOOH@MnO₂ possessed superior properties as catalyst than β-FeOOH, owing to the higher surface hydroxyl density with higher specific surface area, redox ability and electronic transmission rate. Moreover, on the basis of the analysis from FTIR and XPS, it was found that the redox reaction of Fe³⁺/Fe²⁺ and Mn⁴⁺/Mn³⁺ synergistically activated PMS as well as the generation of FeOH⁺ and MnOH²⁺ accelerated activating PMS in the β-FeOOH@MnO₂/PMS system. Thus, MnO₂ and FeOOH synergistically activated PMS to reactive oxygen species (ROS). And ¹O₂, O₂^- and OH were identified as predominant ROS in the β-FeOOH@MnO₂/PMS system on the basis of the result from quenching experiments and ESR. As a result, TOC removal rate was increased up to 22.62%. Additionally, β-FeOOH@MnO₂ exhibited good stability with low iron dissolution and manganese dissolution. Generally, this study proposed that β-FeOOH@MnO₂ was an efficient and environmental catalyst as PMS activator for organic pollutant degradation in water.

Keywords: Peroxymonosulfate; Singlet oxygen; Sulfate radical; Synergetic effect; β-FeOOH@MnO(2).