Electrified Ion Exchange Enabled by Water Dissociation in Bipolar Membranes for Nitrogen Recovery from Source-Separated Urine
Electrified Ion Exchange Enabled by Water Dissociation in Bipolar Membranes for Nitrogen Recovery from Source-Separated Urine
复制标题
双极膜中水解离带电离子交换回收尿液中氮的研究
DOI：
10.1021/acs.est.2c03771
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发表时间：
2022-10-12
影响因子：
11.4
通讯作者：
Tarpeh, William A.
中科院分区：
文献类型：
--
作者：
Dong, Hang;Laguna, Chloe Marie;Tarpeh, William A.
离子交换（IX）是一种有前途的从尿液中选择性回收氮的技术；然而，IX需要化学密集的再生，这增加了能源消耗和碳排放。为了克服这一障碍，我们展示并研究了一种新的电气化IX溶出工艺（EXS），该工艺可以在同步氨溶出的情况下实现电化学原位IX再生。EXS结合弱酸性阳离子交换树脂（WAC）浓缩氨，双极膜产生用于WAC再生的质子，膜剥离从WAC中回收洗脱的铵。在合成尿液和真实尿液的多次吸附-回收循环中，我们观察到超过80%的再生（树脂洗脱）和回收（膜剥离）效率。WAC与强酸性阳离子交换树脂的比较表明，树脂基团的质子亲和力在EXS中调节树脂的可再生性和电导率的关键作用，这与电去离子中材料选择的基本原理不同。与其他使用未经处理的废水作为电解液的电化学回收方法相比，EXS通过wac介导的去除分离和平衡进水铵，实现了回收过程中电解质成分的控制。这种电解质工程促进了可调的EXS能量效率（100-300 MJ/kg N）。这项研究为电气化强化系统的设计提供了信息，该系统能够从尿液中分散回收氮。
Ion exchange (IX) is a promising technology for selective nitrogen recovery from urine; however, IX requires chemical-intensive regeneration that escalates energy consumption and carbon emissions. To overcome this barrier, we demonstrated and investigated a novel electrified IX stripping process (EXS) enabling electrochemical in situ IX regeneration with simultaneous ammonia stripping. EXS combines a weak acid cation exchange resin (WAC) to concentrate ammonia, a bipolar membrane to produce protons for WAC regeneration, and membrane stripping to recover the eluted ammonium from WAC. We observed over 80% regeneration (elution from resin) and recovery (membrane stripping) efficiencies during multiple adsorption-recovery cycles with synthetic and real urine. Comparing WAC with a strong acid cation exchange resin illustrated the critical role of the proton affinity of resin moieties in regulating resin regenerability and conductivity in EXS, which we distinguished from the rationale for material choice in electrodeionization. Compared to other electrochemical recovery methods using unamended wastewater as an electrolyte, EXS enabled control of electrolyte composition during recovery by separating and equalizing influent ammonium via WAC-mediated removal. This electrolyte engineering facilitated tunable EXS energy efficiency (100-300 MJ/kg N). This study informs the design of electrified, intensified systems that enable decentralized nitrogen recovery from urine.