Efficient degradation of chlorpyrifos and intermediate in soil by a novel microwave induced advanced oxidation process: A two-stage reaction

Xiao Shang; Xitao Liu; Xiaoyu Ma; Zhenguo Zhang; Chunye Lin; Mengchang He; Wei Ouyang

doi:10.1016/j.jhazmat.2023.133001

Efficient degradation of chlorpyrifos and intermediate in soil by a novel microwave induced advanced oxidation process: A two-stage reaction

J Hazard Mater. 2024 Feb 15:464:133001. doi: 10.1016/j.jhazmat.2023.133001. Epub 2023 Nov 17.

Authors

Xiao Shang¹, Xitao Liu², Xiaoyu Ma¹, Zhenguo Zhang¹, Chunye Lin¹, Mengchang He¹, Wei Ouyang³

Affiliations

¹ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. Electronic address: liuxt@bnu.edu.cn.
³ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; Advanced Interdisciplinary Institute of Environment and Ecology, Beijing Normal University, Zhuhai 519087, China.

PMID: 37988944
DOI: 10.1016/j.jhazmat.2023.133001

Abstract

The application of microwave/peroxymonosulfate (MW/PMS) in soil remediation has been limited by some shortages including low utilization efficiency of oxidants, low MW absorption capacity of soil particles and incomplete degradation of intermediate. In this study, heating pad waste (HPW) was added in the MW/PMS system to increase the ability of absorbing MW and degradation efficiency of toxic intermediate. A two-stage method for degradation of chlorpyrifos (CPF) and its intermediate 3,5,6-trichloro-2-pyridinol (TCP) by MW/PMS assisted with HPW was proposed. In the first stage, more than 90% of CPF was degraded within 15 min before the addition of HPW, and most of the CPF was converted into TCP through direct or indirect pathways under the action of ¹O₂. In the second stage, more than 70% of the generated TCP was rapidly degraded through SO₄^•- oxidation and electron transfer. The TCP was further degraded with the assistance of HPW through methylation, hydroxylation and dechlorination etc., and the toxicity of degradation products was decreased significantly. pH and soil organic matter had little influences on CPF and TCP degradation. Therefore, a new strategy for remediation of CPF contaminated-soil was provided based on MW/PMS technology and the concept of "treating waste with waste".

Keywords: 3,5,6-trichloro-2-pyridinol; Chlorpyrifos; Electron transfer; Heating pad waste; Microwave/ peroxymonosulfate.