Development of ammonium ion-selective membranes for efficient recovery of ammonia from wastewater

The growing demand for ammonia, driven by its crucial role as a chemical feedstock and potential hydrogen carrier, has intensified the need for sustainable production methods. Conventional ammonia synthesis via the Haber–Bosch process is energy intensive and centralized, and results in high CO₂ emissions. Additionally, the discharge of ammonia into water bodies from various sources contributes to eutrophication. Ammonia recovery from wastewater offers a sustainable solution that addresses pollution mitigation and production limitations. Therefore, this study critically reviewed alternative methods for sustainable ammonia recovery via membrane technology. The current issues hampering the development of membranes for ammonia recovery have been elucidated. Substantial focus has been placed on fundamental strategies for designing and developing ammonium ion-selective nanochannel membranes with well-defined nanoscale channels and pores to control ammonia transport. The challenges and prospects for designing targeted NH₄⁺-selective membranes are highlighted to improve future robust, high-performing, and energy-efficient ammonia recovery from wastewater via an NH₄⁺-selective nanochannel membrane.