Carbon- and energy-efficient water reuse for irrigation

Domestic wastewater can be a resource for water, energy, and nutrients. Conventional wastewater treatment systems incorporate aerobic biological processes and rely upon aeration to oxidize organic matter and ammonium. The result is high energy consumption and a large carbon footprint, primarily due to nitrous oxide emissions. By contrast, strictly anaerobic processes produce methane, a valuable energy resource, which avoids energy-intensive aeration and formation of nitrous oxide, a potent greenhouse gas. It also produces  a nutrient-rich effluent that can offset the need for imported water and fertilizer for irrigation. Through a pilot-scale demonstrations, this project will show proof-of-concept for efficient and sustainable water reuse through anaerobic treatment with ultrafine membranes. In time, the technology could provide carbon- and energy- efficient water reuse to meet irrigation needs, decrease the need for imported water, and point the way for local water reuse in small communities.