State Key Laboratory of Pollution Control and Resource Reuse; Key Laboratory of Urban Water Supply, Water Saving and Water Environment Governance in the Yangtze River Delta of Ministry of Water Resources; College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
School of Municipal and Ecological Engineering, Shanghai Urban Construction Vocational College, Shanghai 200432, China.
Water Res. 2024 Jun 15;257:121708. doi: 10.1016/j.watres.2024.121708. Epub 2024 May 1.
The ammonia recovery from wastewater via electrochemical technologies represents a promising way for wastewater treatment, resource recovery, and carbon emissions reduction. However, chemicals consumption and reactors scalability of the existing electrochemical systems have become the key challenges for their development and application. In this study, a stacked transmembrane electro-chemisorption (sTMECS) system was developed to utilize authigenic acid and base on site for enhancing ammonia recovery from wastewater. The easily scaled up system was achieved via innovatively connecting the cathode chamber in a unit with the anode chamber in the adjacent unit by a hydrophobic gas permeable membrane (GPM). Thus, authigenic base at cathodes and authigenic acid at anodes could be utilized as stripper and absorbent on site to enhance the transmembrane chemisorption of ammonia. Continuous power supply, reducing the distances of electrodes to GPM and moderate aeration of the catholyte could promote ammonia recovery. Applied to the ammonia recovery from the simulated urine, the sTMECS under the current density 62.5 A/cm with a catholyte aeration rate of 3.2 L/(L⋅min) for operation time 4 h showed the transmembrane ammonia flux of 26.00 g N/(m·h) and the system energy consumption of 10.5 kWh/kg N. Accordingly, the developed sTMECS system with chemicals saving, easy scale-up and excellent performance shows good prospects in recovering ammonia from wastewater.
通过电化学技术从废水中回收氨是一种很有前途的废水处理、资源回收和减少碳排放的方法。然而，现有电化学系统的化学品消耗和反应器的可扩展性已成为其发展和应用的关键挑战。在这项研究中，开发了一种堆叠式跨膜电吸附（sTMECS）系统，利用自生酸和碱就地增强从废水中回收氨。通过创新地将一个单元的阴极室与相邻单元的阳极室通过疏水透气膜（GPM）连接，可实现易于放大的系统。因此，阴极处的自生碱和阳极处的自生酸可就地用作汽提剂和吸收剂，以增强氨的跨膜化学吸附。连续供电、缩短电极与 GPM 的距离以及对阴极液适度曝气均可促进氨的回收。将该系统应用于模拟尿液中的氨回收，在电流密度为 62.5 A/cm、阴极液曝气率为 3.2 L/（L·min）、运行时间为 4 h 的条件下，跨膜氨通量为 26.00 g N/（m·h），系统能耗为 10.5 kWh/kg N。因此，开发的 sTMECS 系统具有化学品节约、易于放大和优异的性能，在从废水中回收氨方面具有广阔的前景。
