Removal of dimethoate in drinking water by VUV/UV/Cl2 process
WU Zhengdi1,, CHEN Fangyan1,,, TANG Yubin1, WANG Xingang1, LI Mengkai2, QIANG Zhimin2 1.School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China 2.Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
Abstract:In order to control and remove pesticide residues in drinking water and achieve the purpose of further purification of water quality, a degradation kinetic model was established, and a method for simulating degradation of dimethoate (DMT) in drinking water was selected. DMT is a typical organophosphorus pesticide and is difficult to remove by conventional drinking water treatment technologies. The removal efficiencies of DMT by five treatment processes including ultraviolet (UV), chlorine (Cl2), UV/Cl2, vacuum-UV/UV (VUV/UV) and VUV/UV/Cl2 were investigated comparatively. The effects of initial DMT concentration, Cl2 dosage, solution pH, co-existing natural organic matter (NOM) and inorganic anions (${\rm{NO}}_3^ - $, Cl?, ${\rm{HCO}}_3^ - $, ${\rm{SO}}_4^ {2-} $) in water on DMT degradation by VUV/UV/Cl2 were explored. The results indicated that the VUV/UV/Cl2 process was the most efficient one to remove DMT. The DMT removal rate decreased with the increase of its initial concentration. The increase of the Cl2 dosage to a certain extent improved DMT removal, and the increase of pH also facilitated DMT removal. NOM exhibited a certain inhibition on DMT removal. Co-existing inorganic anions including ${\rm{NO}}_3^ - $, Cl? and ${\rm{HCO}}_3^ - $ in water could capture the hydroxyl radicals (HO·) generated in the reaction system, thus inhibiting DMT removal, while ${\rm{SO}}_4^ {2-} $ reacted with HO· very slowly and did not show any inhibitory effect. Key words:VUV/UV/Cl2/ dimethoate/ removal/ drinking water treatment.
图1VUV/UV细管流反应装置示意图 Figure1.Schematic diagram of the mini-fluidic VUV/UV photoreaction system
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1.School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China 2.Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China Received Date: 2019-04-04 Accepted Date: 2019-07-11 Available Online: 2020-03-02 Keywords:VUV/UV/Cl2/ dimethoate/ removal/ drinking water treatment Abstract:In order to control and remove pesticide residues in drinking water and achieve the purpose of further purification of water quality, a degradation kinetic model was established, and a method for simulating degradation of dimethoate (DMT) in drinking water was selected. DMT is a typical organophosphorus pesticide and is difficult to remove by conventional drinking water treatment technologies. The removal efficiencies of DMT by five treatment processes including ultraviolet (UV), chlorine (Cl2), UV/Cl2, vacuum-UV/UV (VUV/UV) and VUV/UV/Cl2 were investigated comparatively. The effects of initial DMT concentration, Cl2 dosage, solution pH, co-existing natural organic matter (NOM) and inorganic anions (${\rm{NO}}_3^ - $, Cl?, ${\rm{HCO}}_3^ - $, ${\rm{SO}}_4^ {2-} $) in water on DMT degradation by VUV/UV/Cl2 were explored. The results indicated that the VUV/UV/Cl2 process was the most efficient one to remove DMT. The DMT removal rate decreased with the increase of its initial concentration. The increase of the Cl2 dosage to a certain extent improved DMT removal, and the increase of pH also facilitated DMT removal. NOM exhibited a certain inhibition on DMT removal. Co-existing inorganic anions including ${\rm{NO}}_3^ - $, Cl? and ${\rm{HCO}}_3^ - $ in water could capture the hydroxyl radicals (HO·) generated in the reaction system, thus inhibiting DMT removal, while ${\rm{SO}}_4^ {2-} $ reacted with HO· very slowly and did not show any inhibitory effect.
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