Hou Chengsi, Wu Haotian, Zhou Zhengwei, Peng Shuai, Wu Ke, Wang Yue, Xu Longqian, Chen Zuofeng, Lei Zhendong, Wu Deli
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Key Laboratory of Urban Water Supply, Water Saving and Water Environment Governance in the Yangtze River Delta of Ministry of Water Resources, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Key Laboratory of Urban Water Supply, Water Saving and Water Environment Governance in the Yangtze River Delta of Ministry of Water Resources, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
Water Res. 2025 Jan 1;268(Pt A):122589. doi: 10.1016/j.watres.2024.122589. Epub 2024 Oct 8.
Despite flow-electrode capacitive deionization (FCDI) is an emerging technology for desalination, contaminant removal, and resource recovery, the application of conventional FCDI in wastewater treatment is hindered by the electrode selectivity and material costs. In this study, we synthesized a low-cost ammonium (NH) adsorption electrode material by modifying zeolite using ethylenediaminetetraacetic acid disodium salt (EDTA-2Na). The flow electrode prepared by the mixture of EDTA-zeolite and carbon black exhibits a high selectivity and adsorption capacity for the recovery of NH from wastewater. The NH in wastewater passes through the ion exchange membrane and is rapidly adsorbed by the modified zeolite through ion exchange, while Na is retained in the electrolyte. The decrease in NH concentration and the increase in Na concentration in the catholyte lead to a significant change in ion concentration gradient across the membrane. Consequently, the transmembrane selectivity between NH and Na reached 3.46. We validated the feasibility of NH recovery using FCDI with food waste fermentation supernatant. Under optimal operating conditions, 99.15 % of the NH in the fermentation supernatant was removed, and 95.92 % of the NH in the electrolyte was stored in the EDTA-zeolite. By gravitational settling, the NH-rich modified zeolite was separated from carbon black and could be utilized as nitrogen fertilizer. Meanwhile, the mixture of carbon black and brine was used to prepare a fresh electrode suspension. In brief, the FCDI system exhibits a satisfying NH recovery performance and demonstrates a sustainable wastewater resource recovery strategy.
尽管流动电极电容去离子化（FCDI）是一种用于海水淡化、污染物去除和资源回收的新兴技术，但传统FCDI在废水处理中的应用受到电极选择性和材料成本的阻碍。在本研究中，我们通过使用乙二胺四乙酸二钠盐（EDTA-2Na）改性沸石合成了一种低成本的铵（NH）吸附电极材料。由EDTA-沸石和炭黑的混合物制备的流动电极对从废水中回收NH表现出高选择性和吸附能力。废水中的NH通过离子交换膜，通过离子交换被改性沸石快速吸附，而Na保留在电解质中。阴极电解液中NH浓度的降低和Na浓度的增加导致跨膜离子浓度梯度发生显著变化。因此，NH和Na之间的跨膜选择性达到3.46。我们用食物垃圾发酵上清液验证了使用FCDI回收NH的可行性。在最佳操作条件下，发酵上清液中99.15%的NH被去除，电解质中95.92%的NH储存在EDTA-沸石中。通过重力沉降，富含NH的改性沸石与炭黑分离，可作为氮肥使用。同时，炭黑和盐水的混合物用于制备新鲜的电极悬浮液。简而言之，FCDI系统表现出令人满意的NH回收性能，并展示了一种可持续的废水资源回收策略。
