Due to the high volatility of ammonia and contemporaneous condensation of water and ammonia on permeate side, it remains a challenge to obtain a high concentration of ammonia or high-quality water using conventional vacuum membrane distillation (VMD). In this study, a reactive VMD (RVMD) with a two-stage downstream system was developed for simultaneous recovery of ammonia and water from brackish aquaculture effluent with dilute ammonia content. Notably, the RVMD system allowed for complete recovery of dilute ammonia in acid solution. Compared to a conventional VMD system, both the separation factor (SF) and concentration factor (CF) were intensified by 16 times within 2 h using the RVMD system. In the RVMD system, ammonia was first dissolved in acid solution without chilling using immersed trap tube; followed by water vapor condensation under chilling to obtain clean water. It was found that more diluted acid (0.0025 M of sulphuric acid or 0.005 M of phosphoric acid) could be applied to absorb the same amount of ammonia by using this system. Through this system, the recovered ammonia from brackish aquaculture effluent could be concentrated by 23 times (from 19.83 to 465 mg/L) with an SF of 148, while very low ammonia content (0.04 mg/L) was detected in the recovered water. These findings demonstrate that RVMD with a two-stage downstream system outperforms conventional VMD in concentrating ammonia and purifying water.

由于氨的高挥发性以及水和氨在渗透侧同时冷凝，使用传统真空膜蒸馏 (VMD) 获得高浓度氨或优质水仍然是一个挑战。在这项研究中，开发了一种具有两级下游系统的反应性 VMD (RVMD)，用于从氨含量稀的咸水水产养殖废水中同时回收氨和水。值得注意的是，RVMD 系统可以完全回收酸性溶液中的稀氨。与传统的 VMD 系统相比，使用 RVMD 系统，分离因子 (SF) 和浓缩因子 (CF) 在 2 小时内都增强了 16 倍。在RVMD系统中，首先使用浸入式捕集管将氨溶解在酸溶液中而不冷却；然后在冷却下将水蒸气冷凝以获得干净的水。结果发现，使用该系统可以使用更多的稀酸（0.0025 M 硫酸或 0.005 M 磷酸）来吸收相同量的氨。通过该系统，从苦咸水产养殖废水中回收的氨可以浓缩 23 倍（从 19.83 到 465 mg/L），SF 为 148，同时在回收水中检测到非常低的氨含量（0.04 mg/L）。这些发现表明，具有两级下游系统的 RVMD 在浓缩氨和净化水方面优于传统的 VMD。从微咸水产养殖废水中回收的氨可以浓缩 23 倍（从 19.83 到 465 mg/L），SF 为 148，而在回收水中检测到非常低的氨含量（0.04 mg/L）。这些发现表明，具有两级下游系统的 RVMD 在浓缩氨和净化水方面优于传统的 VMD。从微咸水产养殖废水中回收的氨可以浓缩 23 倍（从 19.83 到 465 mg/L），SF 为 148，而在回收水中检测到非常低的氨含量（0.04 mg/L）。这些发现表明，具有两级下游系统的 RVMD 在浓缩氨和净化水方面优于传统的 VMD。