Kathon(CMI-MI),a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one(CMI)and 2-methyl-4-isothiazolin-3-one(MI),was extensively used in industry as a nonoxidizing biocide or disinfectant.However,it would show adverse eff...Kathon(CMI-MI),a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one(CMI)and 2-methyl-4-isothiazolin-3-one(MI),was extensively used in industry as a nonoxidizing biocide or disinfectant.However,it would show adverse effects on aquatic life when it is discharged into surface water.In this study,the removal performance,parameter influence,degradation products and enhancement of subsequent biodegradation of CMI-MI in UV/H_(2)O_(2)system were systematically investigated.The degradation rate of CMI-MI could reach 90%under UV irradiation for 20 min when the dosage of H_(2)O_(2)was 0.3 mmol·L^(–1).The DOC(dissolved organic carbon)mineralization rate of CMI-MI could reach 35%under certain conditions([H_(2)O_(2)]=0.3 mmol·L^(–1),UV irradiation for 40 min).kobs was inversely proportional to the concentration of CMI-MI and proportional to the concentration of H_(2)O_(2).The degradation rate of CMIMI was almost unchanged in the pH range from 4 to 10.Except the presence of CO_(3)^(2-)inhibited the removal rate of CMI-MI,SO_(4)^(2-),Cl^(-),NO_(3)^(-),and NH_(4)^(+) did not interfere with the degradation of CMI-MI in the system.It was found that UV/H_(2)O_(2)system had lower energy consumption and more economic advantage compared with UV/PS system by comparing the EEO(electric energy per order)values under the same conditions.Two main organic products were identified,namely HCOOH and CH_(3)NH_(2).There’s also the formation of Cl^(-)and SO_(4)^(2-).After UV and UV/H_(2)O_(2)photolysis,the biochemical properties of CMI-MI solution were obviously improved,especially the UV/H_(2)O_(2)treatment effect was better,indicating that UV/H_(2)O_(2)technology is expected to combine with biotechnology to remove CMI-MI effectively and environmentally friendly from wastewater.展开更多
基金support of experimental Instrument Platform of Shandong Taihe Water Treatment Technology Co.,LTD.
文摘Kathon(CMI-MI),a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one(CMI)and 2-methyl-4-isothiazolin-3-one(MI),was extensively used in industry as a nonoxidizing biocide or disinfectant.However,it would show adverse effects on aquatic life when it is discharged into surface water.In this study,the removal performance,parameter influence,degradation products and enhancement of subsequent biodegradation of CMI-MI in UV/H_(2)O_(2)system were systematically investigated.The degradation rate of CMI-MI could reach 90%under UV irradiation for 20 min when the dosage of H_(2)O_(2)was 0.3 mmol·L^(–1).The DOC(dissolved organic carbon)mineralization rate of CMI-MI could reach 35%under certain conditions([H_(2)O_(2)]=0.3 mmol·L^(–1),UV irradiation for 40 min).kobs was inversely proportional to the concentration of CMI-MI and proportional to the concentration of H_(2)O_(2).The degradation rate of CMIMI was almost unchanged in the pH range from 4 to 10.Except the presence of CO_(3)^(2-)inhibited the removal rate of CMI-MI,SO_(4)^(2-),Cl^(-),NO_(3)^(-),and NH_(4)^(+) did not interfere with the degradation of CMI-MI in the system.It was found that UV/H_(2)O_(2)system had lower energy consumption and more economic advantage compared with UV/PS system by comparing the EEO(electric energy per order)values under the same conditions.Two main organic products were identified,namely HCOOH and CH_(3)NH_(2).There’s also the formation of Cl^(-)and SO_(4)^(2-).After UV and UV/H_(2)O_(2)photolysis,the biochemical properties of CMI-MI solution were obviously improved,especially the UV/H_(2)O_(2)treatment effect was better,indicating that UV/H_(2)O_(2)technology is expected to combine with biotechnology to remove CMI-MI effectively and environmentally friendly from wastewater.
