Degradation of highly chlorinated pesticide, lindane, in water using UV/persulfate: kinetics and mechanism, toxicity evaluation, and synergism by H2O2

Sanaullah Khan; M Sohail; Changseok Han; Javed Ali Khan; Hasan M Khan; Dionysios D Dionysiou

doi:10.1016/j.jhazmat.2020.123558

Degradation of highly chlorinated pesticide, lindane, in water using UV/persulfate: kinetics and mechanism, toxicity evaluation, and synergism by H₂O₂

J Hazard Mater. 2021 Jan 15:402:123558. doi: 10.1016/j.jhazmat.2020.123558. Epub 2020 Jul 25.

Authors

Sanaullah Khan¹, M Sohail², Changseok Han³, Javed Ali Khan⁴, Hasan M Khan⁴, Dionysios D Dionysiou⁵

Affiliations

¹ Department of Chemistry, Women University, Swabi, 23430, Pakistan; Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan; Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, Ohio, 45221-0012, USA.
² Institute of Chemical Sciences, University of Swat, Swat, 19130, Pakistan.
³ Department of Environmental Engineering, INHA University, Incheon, 22212, Republic of Korea.
⁴ Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan.
⁵ Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, Ohio, 45221-0012, USA. Electronic address: dionysios.d.dionysiou@uc.edu.

PMID: 32759000
DOI: 10.1016/j.jhazmat.2020.123558

Abstract

Sulfate radical-advanced oxidation processes (SR-AOPs) are emerging technologies for decomposing organic pollutants in water. This study investigated the efficiency of UV/persulfate (UV/S₂O₈^2-) process to degrade lindane in water, showing 93.2% lindane removal ([lindane]₀ = 3.43 μM, [S₂O₈^2-]₀ = 100 μM) at a UV fluence of 720 mJ/cm². The lindane degradation followed first order kinetics and mechanistic studies suggested H-abstraction by SO₄^•- and Cl removal via C-Cl bond cleavage by UV-C light. Toxicity assessment using ECOSAR program showed toxicity gradually decreased and eventually no significant toxicity remained when all by-products vanished at high UV dose. Removal efficiency of lindane decreased from 93.2% to 38.4, 45.5, 56.0, 84.3 and 88.6%, by adding 1.0 mg/L humic acid or 1.0 mM CO₃^2-, HCO₃^-, Cl^- or SO₄^2-, respectively. Coupling of H₂O₂ with UV/S₂O₈^2- showed a significant synergistic effect with 99.0% lindane removal at a UV fluence of 600 mJ/cm², using [S₂O₈^2-]₀ = [H₂O₂]₀ = 50 μM while UV/H₂O₂ resulted in only 36.6% lindane removal ([lindane]₀ = 3.43 μM, [H₂O₂]₀ = 100 μM) at a UV fluence of 720 mJ/cm². The results indicate that SR-AOP has potential for consideration as a remedial technology to treat persistent chlorinated pesticides such as lindane in contaminated water.

Keywords: Kinetics and mechanism; Lindane; Sulfate radical-advanced oxidation processes; Toxicity; Water treatment.

Publication types

Research Support, Non-U.S. Gov't