In-situ generation of reactive oxygen species using combination of electrochemical oxidation and metal sulfide

Jong-Gook Kim; Hye-Bin Kim; Dong-Hun Shin; Daniel S Alessi; Eilhann Kwon; Kitae Baek

doi:10.1016/j.scitotenv.2021.147961

In-situ generation of reactive oxygen species using combination of electrochemical oxidation and metal sulfide

Sci Total Environ. 2021 Oct 1:789:147961. doi: 10.1016/j.scitotenv.2021.147961. Epub 2021 May 23.

Authors

Jong-Gook Kim¹, Hye-Bin Kim¹, Dong-Hun Shin¹, Daniel S Alessi², Eilhann Kwon³, Kitae Baek⁴

Affiliations

¹ Department of Environment & Energy, Jeonbuk National University, 567 Baekje-daero, Deokjin, Jeonju, Jeollabukdo 54896, Republic of Korea; Soil Environment Research Center, Jeonbuk National University, 567 Baekje-daero, Deokjin, Jeonju, Jeollabukdo 54896, Republic of Korea.
² Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada.
³ Department of Energy and Environment, Sejong University, Seoul 05006, Republic of Korea.
⁴ Department of Environment & Energy, Jeonbuk National University, 567 Baekje-daero, Deokjin, Jeonju, Jeollabukdo 54896, Republic of Korea; Soil Environment Research Center, Jeonbuk National University, 567 Baekje-daero, Deokjin, Jeonju, Jeollabukdo 54896, Republic of Korea. Electronic address: kbaek@jbnu.ac.kr.

PMID: 34052499
DOI: 10.1016/j.scitotenv.2021.147961

Abstract

In-situ chemical oxidation (ISCO) is commonly practiced to degrade organic pollutants in various fields. However, ISCO is deteriorated the oxidation efficiency due to the non-selective and self-decomposition of reagents. Therefore, in-situ generation of oxidants is being proposed to compensate for the demerits of conventional ISCO. In this study, the aim is to suggest a novel in-situ generation system using the combination of electrochemical oxidation (EO) and pyrite oxidation. It is hypothesized that EO system can generate the oxygen species, which can activate the pyrite surface to produce more oxidants. We evaluated three systems (1) EO system (2) pyrite oxidation system (3) combined system using sulfanilamide as a common antibiotic. The EO system degraded completely sulfanilamide and generated 150 μM of H₂O₂ and 8 mg/L of DO even at 10 mA. In other words, EO system can directly oxidize the sulfanilamide and produce oxygen species. The pyrite system produced 204 and 24 μM of hydroxyl radicals at pH 3 under oxic and anoxic conditions, respectively, and 118 and 20 μM at pH 7. Pyrite oxidation can generate more reactive species in the presence of oxygen. The combined system enhanced the oxidation-rate constant to 1.5 times (from 0.2561 to 0.3502 h^-1). The additional supply of oxygen showed a higher oxidation rate to 1.5 and 1.3 times higher than single EO or pyrite oxidation, respectively. As a result, the co-presence of pyrite and oxygen shows a synergistic effect on the oxidation of the organic pollutant. Our results suggest that electrochemical generation of the oxygen species in the presence of pyrite is a promising technique to oxidize organic pollutants in groundwater.

Keywords: Electrochemical oxidation; Ferrous; Hydrogen peroxide; Hydroxyl radical; Pyrite.

MeSH terms

Hydrogen Peroxide*
Hydroxyl Radical
Oxidation-Reduction
Reactive Oxygen Species
Sulfides*

Substances

Reactive Oxygen Species
Sulfides
Hydroxyl Radical
Hydrogen Peroxide