Eco-engineered ammonia removal via coupled electrocoagulation and ozonation: Process optimization and environmental insights

Ammonia removal from industrial wastewater remains a pressing environmental challenge, yet its sustainability implications are rarely quantified. This study presents integrated performance and life cycle assessment (LCA) of standalone and hybrid processes combining ozonation (O₃) with electrocoagulation (EC) for ammonia-rich effluents. The hybrid O₃ + EC configuration achieved 5.9- and 2.2-fold improvements in removal efficiency over EC and O₃ alone, respectively, reaching 72.4 ± 9.5 % removal under optimal conditions (pH 10.0–10.5, 25 mA/cm², 30 min). The synergistic performance arises from the co-generation of reactive oxygen species and aluminum hydroxide flocs, which accelerate ammonia oxidation and adsorption while minimizing nitrate accumulation. At this optimum, nitrite stabilized at 42.9 ± 7.1 mg/L and nitrate remained below 0.3 mg/L, confirming controlled nitrogen transformation pathways. The integrated system also demonstrated substantial environmental benefits: global warming potential, ozone depletion, and mineral resource depletion were reduced by 76.4 %, 73.8 %, and 74.5 %, respectively, compared to EC alone. These findings establish the O₃ + EC hybrid as a novel, scalable, and environmentally superior technology for ammonia-rich wastewater treatment, bridging performance optimization with life cycle sustainability and industrial feasibility.