He Lingyu, Luo Jiayu, Hu Haiyang, Zhang Xin, Lei Yang
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China.
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China.
Chemosphere. 2025 Sep;384:144510. doi: 10.1016/j.chemosphere.2025.144510. Epub 2025 Jun 4.
Using phosphorus-containing scale inhibitors (i.e., phosphonates) in cooling water poses a significant challenge to water pollution and eutrophication during discharge. Here we report an efficient electrochemical oxidation (EO) process based on a low-cost titanium suboxide (TiO) inert anode. We found that ubiquitous chloride ions (Cl) in cooling water significantly promoted the transformation of methylene phosphonic acid (NTMP, a representative phosphonate) into orthophosphate. In the Cl-TiO-AO system, hypochlorous acid (HOCl) is the primary reactive species responsible for the sequential cleavage of C-P and C-C bonds, converting organic phosphorus into inorganic phosphate. Furthermore, the presence of HCO or humic acid (HA) under realistic conditions showed negligible effects on the degradation of NTMP. In long-term operation, the TiO-AO system sustained 100% conversion efficiency of NTMP over continuous-flow operation mode for more than 720 h, even though the cathode was almost entirely covered with CaCO deposits. The results revealed that cathode scaling does not profoundly affect the conversion of organic phosphorus to phosphate in the TiO-AO system. Overall, our study elucidates the mechanism and robust efficiency of the Cl-TiO-AO system in treating phosphonate-laden wastewater and offers a new solution for dealing with cooling water by coupling electrochemical oxidation with ubiquitous chloride ions.
在冷却水中使用含磷阻垢剂（即膦酸盐）会在排放过程中对水污染和富营养化构成重大挑战。在此，我们报道了一种基于低成本低价钛氧化物（TiO）惰性阳极的高效电化学氧化（EO）工艺。我们发现冷却水中普遍存在的氯离子（Cl）显著促进了亚甲基膦酸（NTMP，一种代表性膦酸盐）向正磷酸盐的转化。在Cl-TiO-AO体系中，次氯酸（HOCl）是负责依次断裂C-P键和C-C键、将有机磷转化为无机磷酸盐的主要活性物种。此外，在实际条件下HCO或腐殖酸（HA）的存在对NTMP的降解影响可忽略不计。在长期运行中，即使阴极几乎完全被CaCO沉积物覆盖，TiO-AO体系在连续流运行模式下NTMP的转化效率仍保持100%超过720小时。结果表明，阴极结垢对TiO-AO体系中有机磷向磷酸盐的转化没有深远影响。总体而言，我们的研究阐明了Cl-TiO-AO体系处理含膦酸盐废水的机制和强大效率，并提供了一种通过将电化学氧化与普遍存在的氯离子耦合来处理冷却水的新解决方案。
