Ye Wen-Kai, Tian Fu-Xiang, Chen Chen, Ye Jing, Liu Fu-Wen, Wang Bo, Hu Xiao-Jun, Xu Bin
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, PR China.
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, PR China.
Chemosphere. 2023 Jun;327:138540. doi: 10.1016/j.chemosphere.2023.138540. Epub 2023 Mar 28.
As the primary inorganic by-product species of ClO, chlorite is believed to have negative toxicological effects on human health and therefrom greatly limits the wide application of ClO in water treatment. The synergistic trimethoprim (TMP) removal concerning degradation efficiency, energy consumption and disinfection by-products (DBPs) formation in the UV activated chlorite process accompanied by the simultaneously elimination of chlorite was comprehensively evaluated. UV/chlorite integrated process removed TMP far more rapidly than UV (1.52%) or chlorite (3.20%) alone due to the endogenous radicals (Cl•, ClO• and •OH), the contributing proportions of which were 31.96%, 19.20% and 44.12%. The second-order rate constants of TMP reaction with Cl•, ClO• and •OH were determined to be 1.75 × 10, 1.30 × 10 and 8.66 × 10 M s. The effects of main water parameters including chlorite dosage, UV intensity, pH as well as water matrixes (nature organic matter, Cl and HCO) were examined. k obeyed the order as UV/Cl>UV/HO≈UV/chlorite>UV, and the cost ranking via electrical energy per order (EE/O, kWh m order) parameter was UV/chlorite (3.7034) > UV/HO (1.1625) >UV/Cl (0.1631). The operational scenarios can be optimized to achieve the maximum removal efficiencies and the minimum energy costs. The destruction mechanisms of TMP were proposed by LC-ESI-MS analysis. The overall weighted toxicity in subsequent disinfection was assessed as UV/Cl>UV/chlorite > UV, the values of which in post-chlorination were 6.2947, 2.5806 and 1.6267, respectively. Owing to the vital roles of reactive chlorine species (RCS), UV/chlorite displayed far higher TMP degradation efficiency than UV, and concurrently presented much less toxicity than UV/Cl. In an effort to determine the viability of the promising combination technology, this study was devoted to reduce and reuse chlorite and synchronously realize the contaminants degradation efficiently.
作为二氧化氯的主要无机副产物，亚氯酸盐被认为对人体健康具有负面毒理学影响，因此极大地限制了二氧化氯在水处理中的广泛应用。本研究全面评估了紫外光活化亚氯酸盐工艺在同时去除亚氯酸盐的情况下，对甲氧苄啶（TMP）的协同去除效果，包括降解效率、能耗和消毒副产物（DBPs）生成情况。由于内源性自由基（Cl•、ClO•和•OH）的存在，紫外/亚氯酸盐联合工艺去除TMP的速度比单独的紫外（1.52%）或亚氯酸盐（3.20%）快得多，其贡献比例分别为31.96%、19.20%和44.12%。测定了TMP与Cl•、ClO•和•OH反应的二级速率常数分别为1.75×10、1.30×10和8.66×10 M s。考察了亚氯酸盐投加量、紫外强度、pH值以及水基质（天然有机物、Cl和HCO）等主要水质参数的影响。k遵循紫外/Cl>紫外/H₂O₂≈紫外/亚氯酸盐>紫外的顺序，通过每级电能（EE/O，kWh m⁻³ order⁻¹）参数计算的成本排序为紫外/亚氯酸盐（3.7034）>紫外/H₂O₂（1.1625）>紫外/Cl（0.1631）。可以优化运行方案以实现最大去除效率和最低能源成本。通过液相色谱 - 电喷雾电离质谱（LC - ESI - MS）分析提出了TMP的破坏机制。后续消毒中的总体加权毒性评估为紫外/Cl>紫外/亚氯酸盐>紫外，后氯化处理中的值分别为6.2947、2.5806和1.6267。由于活性氯物种（RCS）的重要作用，紫外/亚氯酸盐显示出比紫外更高的TMP降解效率，同时毒性比紫外/Cl小得多。为了确定这种有前景的联合技术的可行性，本研究致力于减少和再利用亚氯酸盐，并同步高效实现污染物降解。
