Hybrid Donnan dialysis-electrodialysis for efficient ammonia recovery from anaerobic digester effluent

Zhinan Dai; Cong Chen; Yifan Li; Haoquan Zhang; Jingmei Yao; Mariana Rodrigues; Philipp Kuntke; Le Han

doi:10.1016/j.ese.2023.100255

Hybrid Donnan dialysis-electrodialysis for efficient ammonia recovery from anaerobic digester effluent

Environ Sci Ecotechnol. 2023 Feb 17:15:100255. doi: 10.1016/j.ese.2023.100255. eCollection 2023 Jul.

Authors

Zhinan Dai¹, Cong Chen¹, Yifan Li¹, Haoquan Zhang¹, Jingmei Yao¹, Mariana Rodrigues^{2

3}, Philipp Kuntke^{2

3}, Le Han¹

Affiliations

¹ 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.
² Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9 8911MA Leeuwarden P.O. Box 1113, 8900 CC, Leeuwarden, the Netherlands.
³ Environmental Technology, Wageningen University, Bornse Weilanden 9 6708 WG Wageningen P.O. Box 17, 6700 AA, Wageningen, the Netherlands.

Abstract

Ammonia recovery from wastewater is crucial, yet technology of low carbon emission and high ammonia perm-selectivity against complex stream compositions is urgently needed. Herein, a membrane-based hybrid process of the Donnan dialysis-electrodialysis process (DD-ED) was proposed for sustainable and efficient ammonia recovery. In principle, DD removes the majority of ammonia in wastewater by exploring the concentration gradient of NH₄ ⁺ and driven cation (Na⁺) across the cation exchange membrane, given industrial sodium salt as a driving chemical. An additional ED stage driven by solar energy realizes a further removal of ammonia, recovery of driven cation, and replenishment of OH^- toward ammonia stripping. Our results demonstrated that the hybrid DD-ED process achieved ammonia removal efficiency >95%, driving cation (Na⁺) recovery efficiency >87.1% for synthetic streams, and reduced the OH^- loss by up to 78% compared to a standalone DD case. Ammonia fluxes of 98.2 g_N m^-2 d^-1 with the real anaerobic digestion effluent were observed using only solar energy input at 3.8 kWh kg_N ^-1. With verified mass transfer modeling, reasonably controlled operation, and beneficial recovery performance, the hybrid process can be a promising candidate for future nutrient recovery from wastewater in a rural, remote area.

Keywords: Ammonia recovery; Anaerobic digester effluent; Brine utilization; Donnan Dialysis; Electrodialysis.