Degradation of thiocyanate by Fe/Cu/C microelectrolysis: Role of pre-magnetization and enhancement mechanism

Min Zhang; Jin Wang; Xinyuan Zhan; Wusong Xu; Maolin He; Ding Ma; Zhengbo Yue

doi:10.1016/j.envres.2024.118833

Degradation of thiocyanate by Fe/Cu/C microelectrolysis: Role of pre-magnetization and enhancement mechanism

Environ Res. 2024 Apr 9;252(Pt 2):118833. doi: 10.1016/j.envres.2024.118833. Online ahead of print.

Authors

Min Zhang¹, Jin Wang², Xinyuan Zhan³, Wusong Xu¹, Maolin He¹, Ding Ma³, Zhengbo Yue⁴

Affiliations

¹ School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China.
² School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China; Anhui Engineering Research Center of Industrial Wastewater Treatment and Resource Recovery, Hefei University of Technology, Hefei, Anhui, 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui, 230009, China. Electronic address: sophiawj@hfut.edu.cn.
³ School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China; Anhui Engineering Research Center of Industrial Wastewater Treatment and Resource Recovery, Hefei University of Technology, Hefei, Anhui, 230009, China.
⁴ School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui, 230009, China; Anhui Engineering Research Center of Industrial Wastewater Treatment and Resource Recovery, Hefei University of Technology, Hefei, Anhui, 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui, 230009, China. Electronic address: zbyue@hfut.edu.cn.

PMID: 38599446
DOI: 10.1016/j.envres.2024.118833

Abstract

Thiocyanate (SCN^-), a non-volatile inorganic pollutant, is commonly found in various types of industrial wastewater, which is resistant to hydrolysis and has the potential to be toxic to organisms. Premagnetized iron-copper-carbon ternary micro-electrolytic filler (pre-Fe/Cu/C) was prepared to degrade SCN^-. Pre-Fe/Cu/C exhibited the most significant enhancement effect on SCN^- removal when magnetized for 5 min with an intensity of 100 mT, and the SCN^- removal rate was the highest at an initial pH of 3.0 and an aeration rate of 1.6 L/min. The electrochemical corrosion and electron transfer in the pre-Fe/Cu/C system were confirmed through SEM, XPS, FTIR, XRD, and electrochemical tests. This resulted in the formation of more corrosion products and multiple cycles of Fe²⁺/Fe³⁺ and Cu⁰/Cu⁺/Cu²⁺. Additionally, density functional theory (DFT) calculations and electron paramagnetic resonance (EPR) were utilized to illustrate the oxygen adsorption properties of the materials and the participation of reactive oxygen species (¹O₂, ·O₂^-, and ·OH) in SCN^- removal. The degradation products of SCN^- were identified as SO₄^2-, HCO₃^-, NH₄⁺, and N₂. This study introduced the use of permanent magnets for the first time to enhance Fe/Cu/C ternary micro-electrolytic fillers, offering a cost-effective, versatile, and stable approach that effectively effectively enhanced the degradation of SCN^-.

Keywords: Degradation pathway; Enhanced degradation; Microelectrolysis; Premagnetized iron-copper-carbon material; Thiocyanate removal.