College of Environmental and Chemical Engineering, Shanghai Engineering Research Center of Energy, Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
College of Environmental and Chemical Engineering, Shanghai Engineering Research Center of Energy, Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090, China.
J Environ Sci (China). 2025 Feb;148:399-408. doi: 10.1016/j.jes.2024.01.021. Epub 2024 Jan 30.
A mixed oxidant of chlorine dioxide (ClO) and NaClO was often used in water treatment. A novel UVA-LED (365 nm)-activated mixed ClO/NaClO process was proposed for the degradation of micropollutants in this study. Carbamazepine (CBZ) was selected as the target pollutant. Compared with the UVA/ClO process, the UVA/ClO/NaClO process can improve the degradation of CBZ, with the rate constant increasing from 2.11×10 sec to 2.74×10 sec. In addition, the consumption of oxidants in the UVA/ClO/NaClO process (73.67%) can also be lower than that of UVA/NaClO (86.42%). When the NaClO ratio increased, both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA/ClO/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/ClO/NaClO process. When ClO 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), and nitrate ion (NO) can promote the reaction system. As the concentration of NaClO in the reaction solution increased, the generation of chlorates will decrease. The UVA/ClO/NaClO process can effectively control the formation of volatile disinfection by-products (DBPs), and with the increase of ClO dosage, the formation of DBPs can also decrease.
二氧化氯（ClO）和次氯酸钠（NaClO）的混合氧化剂常用于水处理。本研究提出了一种新型的紫外光-LED（365nm）激活的混合 ClO/NaClO 工艺，用于降解水中的微量污染物。卡马西平（CBZ）被选为目标污染物。与 UVA/ClO 工艺相比，UVA/ClO/NaClO 工艺可以提高 CBZ 的降解速率，速率常数从 2.11×10 sec 增加到 2.74×10 sec。此外，UVA/ClO/NaClO 工艺中氧化剂的消耗（73.67%）也可以低于 UVA/NaClO（86.42%）。当 NaClO 比例增加时，UVA/ClO/NaClO 工艺中 CBZ 的降解效率和氧化剂的消耗都可以增加。溶液 pH 值会影响 NaClO 在总氧化剂中的比例。当 pH 值范围为 6.0-8.0 时，组合工艺可以生成更多的活性物质，促进 CBZ 的降解。在 UVA/ClO/NaClO 工艺中，研究了氧化剂摩尔比对活性物质的影响。当 ClO 作为主要氧化剂时，HO•和 Cl•是主要的活性物质，而当 NaClO 是主要氧化剂时，ClO•在体系中发挥作用。氯离子（Cl）、碳酸氢根离子（HCO）和硝酸根离子（NO）都可以促进反应体系。随着反应溶液中 NaClO 浓度的增加，氯酸盐的生成量会减少。UVA/ClO/NaClO 工艺可以有效地控制挥发性消毒副产物（DBPs）的形成，随着 ClO 剂量的增加，DBPs 的形成也会减少。
