Efficient degradation of sulfamethoxazole in various waters with peroxymonosulfate activated by magnetic-modified sludge biochar: Surface-bound radical mechanism

Xi Chen; Shufang Qian; Yongfei Ma; Jinyao Zhu; Shitai Shen; Jiayi Tang; Yongzhen Ding; Suli Zhi; Keqiang Zhang; Lie Yang; Zulin Zhang

doi:10.1016/j.envpol.2023.121010

Efficient degradation of sulfamethoxazole in various waters with peroxymonosulfate activated by magnetic-modified sludge biochar: Surface-bound radical mechanism

Environ Pollut. 2023 Feb 15:319:121010. doi: 10.1016/j.envpol.2023.121010. Epub 2023 Jan 3.

Authors

Xi Chen¹, Shufang Qian¹, Yongfei Ma¹, Jinyao Zhu¹, Shitai Shen¹, Jiayi Tang¹, Yongzhen Ding², Suli Zhi², Keqiang Zhang², Lie Yang¹, Zulin Zhang³

Affiliations

¹ Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, China.
² Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.
³ Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, China; The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK. Electronic address: Zulin.Zhang@hutton.ac.uk.

PMID: 36608732
DOI: 10.1016/j.envpol.2023.121010

Abstract

First time, this study synthesized a magnetic-modified sludge biochar (MSBC) as an activator of peroxymonosulfate (PMS) to eliminate sulfamethoxazole (SMX). The removal efficiency of SMX reached 96.1% at t = 60 min by PMS/MSBC system. The larger surface area and magnetic Fe₃O₄ of MSBC surface enhanced its activation performance for PMS. The PMS decomposition, premixing and reactive oxygen species (ROS) identification experiments combined with Raman spectra analysis demonstrated that the degradation process was dominated by surface-bound radicals. The transformed products (TPs) of SMX and the main degradation pathways were identified and proposed. The ecotoxicity of all TPs was lower than that of SMX. The magnetic performance was beneficial for its reuse and the removal efficiency of SMX was 83.3% even after five reuse cycles. Solution pH, HCO₃^- and CO₃^2- were the critical environmental factors affecting the degradation process. MSBC exhibited environmental safety for its low heavy metal leaching. PMS/MSBC system also performed excellent removal performance for SMX in real waters including drinking water (88.1%), lake water (84.3%), Yangtze River water (83.0%) and sewage effluent (70.2%). This study developed an efficient PMS activator for SMX degradation in various waters and provided a workable way to reuse and recycle municipal sludge.

Keywords: Magnetic-modified sludge biochar; Peroxymonosulfate; Resources recovery; Sulfamethoxazole; Surface-bound radicals.

MeSH terms

Magnetic Phenomena
Peroxides / chemistry
Sewage
Sulfamethoxazole* / chemistry
Water
Water Pollutants, Chemical* / analysis

Substances

Sulfamethoxazole
biochar
Sewage
peroxymonosulfate
Water Pollutants, Chemical
Peroxides
Water