Sustainable removal of ammonia from anaerobic-lagoon swine waste effluents using an electrochemically-regenerated ion exchange process
The research paper presents a novel method for removing ammonia from swine waste effluents using a combination of ion exchange (IX) and electrochemical regeneration. The process involves a daily cycle of adsorption, chemical regeneration, and electrooxidation of ammonia, effectively reducing ammonia concentrations from approximately 1000 mg/L to around 60 mg/L. The operational sequence includes an adsorption phase lasting 180 minutes, a chemical regeneration phase of 125 minutes, and an electrooxidation phase of 8 hours, which is conducted during low-cost electricity hours.
The study emphasizes the feasibility and cost-effectiveness of this method, with operational costs estimated at $3.057 per kg of ammonia oxidized, where operational expenses (OPEX) account for 88.4% of the total cost. The research identifies optimal operational conditions, such as a 12.5 bed volume adsorption step and a hydraulic retention time of 14.5 minutes, which allow for continuous operation without the need for frequent replenishment of the regenerant solution.
The research paper also discusses the challenges associated with competing cations in the wastewater, which can affect the efficiency of ammonia removal. The authors highlight the importance of maintaining a stable concentration of potassium ions in the regenerant solution to achieve over 90% ammonia removal efficiency. The study concludes that the proposed method can significantly mitigate the environmental impact of ammonia-rich swine effluents, which are a major concern in agricultural waste management.
This research paper is significant in the field of environmental engineering and agricultural waste management as it addresses the pressing issue of ammonia pollution from swine farming, a major contributor to environmental degradation. The proposed electrochemically-regenerated ion exchange process offers a sustainable alternative to traditional biological methods, which often face limitations in efficiency and operational stability. By demonstrating a cost-effective and efficient method for ammonia removal, the study contributes to ongoing discussions about sustainable agricultural practices and wastewater treatment technologies. The findings can benefit researchers, practitioners, and policymakers by providing insights into innovative solutions for managing agricultural waste and reducing its environmental footprint.
