Bipolar Membrane Electrodialysis for Ammonia Recovery from Synthetic Urine: Experiments, Modeling, and Performance Analysis
Bipolar Membrane Electrodialysis for Ammonia Recovery from Synthetic Urine: Experiments, Modeling, and Performance Analysis
复制标题
DOI：
10.1021/acs.est.1c05316
复制
发表时间：
2021-10-12
影响因子：
11.4
通讯作者：
Lin, Shihong
中科院分区：
文献类型：
--
作者：
Li, Yujiao;Wang, Ruoyu;Lin, Shihong
从源头分离的尿液中回收氮是可持续氮管理的重要组成部分。提出了一种新型的双极膜-膜接触器电渗析工艺，用于从来源分离的合成尿液中高效地回收氨(类似于3772mgN L-1)。在BMED-MC过程中，双极膜中的电驱动水解离同时增加了尿流的pH值，并产生了用于氨汽提的酸流。随着尿液pH值的升高，氨通过膜接触器中的透气膜传输，并被酸流回收为可直接用作肥料的硫酸铵。批式实验结果表明，BMED-MC工艺的回收率可达90%。通过改变电流密度，可以调节平均氨通量和比能耗。在电流密度为20 mA cm(-2)的条件下，实现7h间歇式氨回收67.5%所需的能量，对于单膜堆的小试系统为92.8MJ kg(-1)N，对于多膜堆的大型系统可达到25.8MJ kg(-1)N，平均氨通量为2.2molm(-2)h(-1)。模拟结果表明，连续的BMED-MC工艺能以较低的能耗(12.5MJ·kg~(-1)N)实现90%的氨回收率。BMed-MC显示了从来源分离的尿液中回收氨的巨大潜力，因为它相对能源效率高，并且不需要外部酸溶液。
Recovering nitrogen from source-separated urine is an important part of the sustainable nitrogen management. A novel bipolar membrane electrodialysis with membrane contactor (BMED-MC) process is demonstrated here for efficient recovery of ammonia from synthetic source-separated urine (similar to 3772 mg N L-1). In a BMED-MC process, electrically driven water dissociation in a bipolar membrane simultaneously increases the pH of the urine stream and produces an acid stream for ammonia stripping. With the increased pH of urine, ammonia transports across the gas-permeable membrane in the membrane contactor and is recovered by the acid stream as ammonium sulfate that can be directly used as fertilizer. Our results obtained using batch experiments demonstrate that the BMED-MC process can achieve 90% recovery. The average ammonia flux and the specific energy consumption can be regulated by varying the current density. At a current density of 20 mA cm(-2), the energy required to achieve a 67.5% ammonia recovery in a 7 h batch mode is 92.8 MJ kg(-1) N for a bench-scale system with one membrane stack and can approach 25.8 MJ kg(-1) N for large-scale systems with multiple membrane stacks, with an average ammonia flux of 2.2 mol m(-2) h(-1). Modeling results show that a continuous BMED-MC process can achieve a 90% ammonia recovery with a lower energy consumption (i.e., 12.5 MJ kg(-1) N). BMED-MC shows significant potential for ammonia recovery from source-separated urine as it is relatively energy-efficient and requires no external acid solution.