Sustainable treatment and utilization of source-separated urine and wastewater using bioelectrochemical systems

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Wastewater (including human urine) has been considered as unwanted "waste" that needs to be treated by consuming energy and other resources. However, organics and nutrients in wastewater can be converted into electricity, hydrogen gas, and land fertilizers (struvite). This research will establish innovative methods to utilize wastewater as a resource for energy and nutrients. Outcomes of this research will provide solutions to the major challenges in wastewater treatment (i.e., energy consumption, nutrient removal, and biosolids). In bioelectrochemical systems (BESs), exoelectrogenic bacteria oxidize organic matter and transfer electrons to the anode, creating electric current. This electrogenic capability enables electric power generation and hydrogen gas production, converting organic contaminants into useful energy sources. In addition, electrode reactions induce ionic movement that can be manipulated to concentrate nutrient ions (ammonium and phosphate ions), by schematically placing ion-exchange membranes (IEMs) in BESs. Highly concentrated nutrients will facilitate struvite recovery from wastewater or human urine. Biosolids treatment and disposal require the major costs in conventional wastewater treatment. Our preliminary study confirmed a very small biosolids production in BESs. Further investigation will optimize BESs for minimal biosolids and maximal substrate removal, suggesting BESs as a promising alternative for wastewater treatment. A pilot-scale study will demonstrate practical wastewater treatment with reduced biosolids and energy recovery. From this research, the wastewater treatment industry will be benefitted with biosolids reduction and energy recovery, minimizing the overall treatment costs. Struvite recovery will create profits from wastewater treatment and also help resolve global phosphorus depletion. Effective nutrient recovery will reduce risks of eutrophication in natural water systems, maintaining a clean environment in Canada. Eventually, this research will provide opportunities to Canada for sustainable and effective wastewater treatment and utilization.