Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400045, PR China.
UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia.
Environ Sci Technol. 2021 May 18;55(10):7015-7024. doi: 10.1021/acs.est.0c08772. Epub 2021 Apr 27.
This work proposed an innovative and energy-efficient Donnan Dialysis (DD) and Osmotic Distillation (OD) hybrid process for alkali-driven ammonium recovery from wastewater. The efficiency and feasibility of ammonium removal and recovery from synthetic and real wastewater using NaOH and waste alkali were investigated. Ammonium in the feed first transported across the cation exchange membrane and accumulated in the receiver chamber. It is then deprotonated as ammonia, passing through the gas permeable membrane and finally is fixed as ammonium salt in the acid chamber. Our results indicated that employing waste alkali (red mud leachate) as driving solution led to excellent ammonium recovery performances (recovery efficiency of >80%), comparable to those of NaOH solution. When the initial ammonium concentration was 5 and 50 mM, the waste alkali driven DD-OD process achieved acceptable NH-N flux density of 16.8 and 169 g N m d, at energy cost as low as 8.38 and 2.06 kWh kg N, respectively. Since this alkali driven DD-OD hybrid process is based on solute concentration (or partial pressure) gradient, it could be an energy-effective technology capable of treating wastewaters containing ammonium using waste alkali to realize nutrients recovery in a sustainable manner.
本工作提出了一种创新且节能的 Donnan 透析（DD）和渗透蒸馏（OD）混合工艺，用于从废水中提取碱性驱动的铵。研究了使用 NaOH 和废碱从合成废水和实际废水去除和回收铵的效率和可行性。进料中的铵首先穿过阳离子交换膜并在接收器室中积累。然后，它作为氨被去质子化，穿过透气膜，最终在酸室中固定为铵盐。我们的结果表明，采用废碱（赤泥浸出液）作为驱动溶液可实现优异的铵回收性能（回收效率>80%），与 NaOH 溶液相当。当初始铵浓度分别为 5 和 50 mM 时，废碱驱动的 DD-OD 工艺可实现可接受的 NH-N 通量密度为 16.8 和 169 g N m d，能耗分别低至 8.38 和 2.06 kWh kg N。由于这种基于溶质浓度（或分压）梯度的碱性驱动 DD-OD 混合工艺，它可能是一种节能技术，能够使用废碱处理含铵废水，以可持续的方式实现营养物回收。
