由于其环境风险和潜在价值,膦酸酯正成为全球关注和关注的问题。将磷酸盐降解为磷酸盐,然后进行回收被认为是控制磷酸盐污染的有前途的策略。缓解磷危机,促进磷循环。鉴于这些目标,制备了掺杂有Fe-Co基碳催化剂的阴离子膜涂覆电极(A-MCE)和掺杂有碳基催化剂的阳离子膜涂覆电极(C-MCE)作为催化电极,并开发了一种新型的电催化电容去离子(E-CDI)。充电过程中,基于静电吸引,膦酸酯在A-MCE表面周围富集,配体交换,和氢键。同时,Fe2+和Co2+自氧化成Fe3+和Co3+,与富集的膦酸酯形成复合物,并实现分子内电子转移过程以降解膦酸酯。此外,受益于C-MCE稳定的溶解氧和高的氧还原反应活性,过氧化氢积累在E-CDI中(158μM),因此通过活化产生羟基自由基(·OH)。E-CDI为·OH和膦酸酯之间的有效反应提供了理想的平台,避免·OH的损失和引发大多数膦酸酯的选择性降解。充电70分钟后,约89.9%的膦酸酯降解为磷酸盐,磷酸盐随后被A-MCE吸附。结果还表明,膦酸酯降解高度依赖于溶液的pH和电压,并且受电解质浓度的影响不明显。与传统的高级氧化工艺相比,E-CDI表现出更高的降解效率,更低的成本,在处理模拟废水时对共存离子不太敏感。膦酸酯的自增强和选择性降解,首次通过E-CDI系统同时实现了磷酸盐的原位吸附,在处理含有机物的含盐废水方面显示出很高的前景。
Phosphonate is becoming a global interest and concern owing to its environment risk and potential value. Degradation of
phosphonate into phosphate followed by the recovery is regarded as a promising strategy to control
phosphonate pollution, relieve phosphorus crisis, and promote phosphorus cycle. Given these objectives, an anion-membrane-coated-electrode (A-MCE) doped with Fe-Co based carbon catalyst and cation-membrane-coated-electrode (C-MCE) doped with carbon-based catalyst were prepared as catalytic electrodes, and a novel electrocatalytic capacitive deionization (E-CDI) was developed. During charging process, phosphonate was enriched around A-MCE surface based on electrostatic attraction, ligand exchange, and hydrogen bond. Meanwhile, Fe2+ and Co2+ were self-oxidized into Fe3+ and Co3+, forming a complex with enriched phosphonate and enabling an intramolecular electron transfer process for
phosphonate degradation. Additionally, benefiting from the stable dissolved oxygen and high oxygen reduction reaction activity of C-MCE, hydrogen peroxide accumulated in E-CDI (158 μM) and thus hydroxyl radicals (·OH) were generated by activation. E-CDI provided an ideal platform for the effective reaction between ·OH and phosphonate, avoiding the loss of ·OH and triggering selective degradation of most
phosphonate. After charging for 70 min, approximately 89.9% of phosphonate was degraded into phosphate, and phosphate was subsequently adsorbed by A-MCE. Results also showed that phosphonate degradation was highly dependent on solution pH and voltage, and was insignificantly affected by electrolyte concentration. Compared to traditional advanced oxidation processes, E-CDI exhibited a higher degradation efficiency, lower cost, and less sensitive to co-existed ions in treating simulated wastewaters. Self-enhanced and selective degradation of phosphonate, and in-situ phosphate adsorption were simultaneously achieved for the first time by a E-CDI system, showing high promise in treating organic-containing saline wastewaters.