The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the singl...The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given.The SET mechanism between ClO2and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200 88 kJ/mol.展开更多
A mixed oxidant of chlorine dioxide(ClO_(2))and NaClO was often used in water treatment.A novel UVA-LED(_(365) nm)-activated mixed ClO_(2)/NaClO process was proposed for the degradation of micropollutants in this stud...A mixed oxidant of chlorine dioxide(ClO_(2))and NaClO was often used in water treatment.A novel UVA-LED(_(365) nm)-activated mixed ClO_(2)/NaClO process was proposed for the degradation of micropollutants in this study.Carbamazepine(CBZ)was selected as the target pollutant.Compared with the UVA_(365)/ClO_(2) process,the UVA_(365)/ClO_(2)/NaClO process can improve the degradation of CBZ,with the rate constant increasing from 2.11×10^(−4) sec^(−1) to 2.74×10^(−4) sec^(−1).In addition,the consumption of oxidants in the UVA_(365)/ClO_(2)/NaClO process(73.67%)can also be lower than that of UVA_(365)/NaClO(86.42%).When the NaClO ratio increased,both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA_(365)/ClO_(2)/NaClO process.The solution pH can affect the contribution of NaClO in the total oxidant ratio.When the pH range of 6.0-8.0,the combination process can generate more active species to promote the degradation of CBZ.The change of active species with oxidant molar ratio was investigated in the UVA_(365)/ClO_(2)/NaClO process.When ClO_(2) acted as the main oxidant,HO·and Cl·were the main active species,while when NaClO was the main oxidant,ClO·played a role in the system.Both chloride ion(Cl^(-)),bicarbonate ion(HCO_(3)^(-)),and nitrate ion(NO_(3)^(-))can promote the reaction system.As the concentration of NaClO in the reaction solution increased,the generation of chlorates will decrease.The UVA_(365)/ClO_(2)/NaClO process can effectively control the formation of volatile disinfection by-products(DBPs),and with the increase of ClO_(2) dosage,the formation of DBPs can also decrease.展开更多
文摘The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given.The SET mechanism between ClO2and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200 88 kJ/mol.
基金supported by the National Natural Science Foundation of China (No.52170006)。
文摘A mixed oxidant of chlorine dioxide(ClO_(2))and NaClO was often used in water treatment.A novel UVA-LED(_(365) nm)-activated mixed ClO_(2)/NaClO process was proposed for the degradation of micropollutants in this study.Carbamazepine(CBZ)was selected as the target pollutant.Compared with the UVA_(365)/ClO_(2) process,the UVA_(365)/ClO_(2)/NaClO process can improve the degradation of CBZ,with the rate constant increasing from 2.11×10^(−4) sec^(−1) to 2.74×10^(−4) sec^(−1).In addition,the consumption of oxidants in the UVA_(365)/ClO_(2)/NaClO process(73.67%)can also be lower than that of UVA_(365)/NaClO(86.42%).When the NaClO ratio increased,both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA_(365)/ClO_(2)/NaClO process.The solution pH can affect the contribution of NaClO in the total oxidant ratio.When the pH range of 6.0-8.0,the combination process can generate more active species to promote the degradation of CBZ.The change of active species with oxidant molar ratio was investigated in the UVA_(365)/ClO_(2)/NaClO process.When ClO_(2) acted as the main oxidant,HO·and Cl·were the main active species,while when NaClO was the main oxidant,ClO·played a role in the system.Both chloride ion(Cl^(-)),bicarbonate ion(HCO_(3)^(-)),and nitrate ion(NO_(3)^(-))can promote the reaction system.As the concentration of NaClO in the reaction solution increased,the generation of chlorates will decrease.The UVA_(365)/ClO_(2)/NaClO process can effectively control the formation of volatile disinfection by-products(DBPs),and with the increase of ClO_(2) dosage,the formation of DBPs can also decrease.
