title: Gamma radiolytic decomposition of endosulfan in aerated solution: the role of carbonate radical.
abstract: The present study elaborates the removal of endosulfan, an emerging water pollutant and potential carcinogenic, in aerated solution. The influence of Cl(-), NO3 (-), NO2 (-), CO3 (2-), HCO3 (-), SO3 (2-), and humic acid was assessed on the radiolytic degradation of endosulfan. A strong inhibition on the radiolytic degradation of endosulfan was observed in the presence of NO3 (-), NO2 (-), and SO3 (2-). Instead, a slight increase in the removal efficiency of endosulfan was observed at high concentrations of CO3 (2-) and HCO3 (-). The formation of CO3 (•-) in radiolytic degradation of endosulfan in the presence of CO3 (2-) and HCO3 (-) was demonstrated by adding SO3 (2-) that rapidly react with CO3 (•-). The results indicate that CO3 (•-) formed from the reactions of CO3 (2-) and HCO3 (-) and commonly found in natural water can play an important role in the degradation of endosulfan and other sulfur containing electron-rich compounds. The study showed faster degradation of endosulfan at lower concentration compared to high concentration and removal was found to follow pseudo-first-order kinetic. Endosulfan ether was found as the main degradation product and degradation pathway was found to be initiated at the S=O bond of endosulfan. The efficiency of gamma irradiation in the removal of endosulfan was examined in terms of formation of short chain organic acids and chloride ion accumulation.
authors.affiliation: Department of Environmental Sciences, COMSATS Institute of Information Technology, Vehari, 61100, Pakistan. noorsamad@ciitvehari.edu.pk.|Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan. noorsamad@ciitvehari.edu.pk.
authors.forename: Noor S
authors.initials: NS
authors.lastname: Shah
authors.affiliation: Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan.
authors.forename: Javed Ali
authors.initials: JA
authors.lastname: Khan
authors.affiliation: Petroleum and Chemical Engineering Department, Faculty of Engineering, Sultan Qaboos University, Muscat, Oman.
authors.forename: Ala'a H
authors.initials: AH
authors.lastname: Al-Muhtaseb
authors.affiliation: Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan.|Department of Chemistry, COMSATS Institute of Information Technology, Abbotabad, 22060, Pakistan.
authors.forename: Murtaza
authors.initials: M
authors.lastname: Sayed
authors.affiliation: Radiation Chemistry Laboratory, National Centre of Excellence in Physical Chemistry, University of Peshawar, Peshawar, 25120, Pakistan. hmkhan@upesh.edu.pk.
authors.forename: Hasan M
authors.initials: HM
authors.lastname: Khan
mesh_terms: D002254:Carbonates / Q000737:chemistry*; D004726:Endosulfan / Q000031:analogs & derivatives / Q000032:analysis* / Q000737:chemistry; D005720:Gamma Rays; D007700:Kinetics; D012996:Solutions; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002254:Carbonates; D012996:Solutions; D014874:Water Pollutants, Chemical; C544690:endosulfan ether; D014867:Water; D004726:Endosulfan
keywords: AOPs; Carbonate radical; Endosulfan; Gamma irradiation; Water treatment