Closing wastewater treatment energy balance through advanced nutrient removal and recovery

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The proposed research will improve the environmental sustainability of wastewater treatment by simplifying the process of nitrogen removal and lowering its cost. It will increase the opportunity for phosphorus removal in different locations in the wastewater treatment facility and its subsequent recovery by commercial processes. The team assembled for this research has three main objectives. The first objective is to apply a novel technology where hydrogen gas is used to remove nitrogen using membrane biofilm reactors. This will be done by using non-porous membranes, which is a new technology at the prototype stage, therefore, allowing for exploration and discovery of new methods of nitrogen removal from wastewater and groundwater. In the second objective we propose to investigate the potential for recovery of supernatant from sludge treatment before anaerobic methane-generating digestion, using acid fermentation. This will result in the removal of filamentous microorganisms so they do not contribute to foaming in anaerobic digestion. The process is expected to lead to better digestibility of the sludge and improved methane generation, and an increase in phosphorus-rich supernatant for subsequent phosphorus recovery. The third objective involves a new anaerobic membrane bioreactor that introduces electrodes supplied with very low direct current to produce a high-quality effluent for non-potable industrial reuse. The impetus for this research is the fact that agricultural wastes and manures in the Prairies are required to use anaerobic digestion and removal of phosphorus, which causes eutrophication of Prairie lakes. This research will develop a mechanism by which phosphorus is solubilized and thus easily removed using magnesium compounds thus producing a usable fertilizer called struvite. The impact on Canadian economy of the research to be realized by the assembled team under my guidance is very significant: improve energy use and management at wastewater treatment plants; resolution of phosphorus removal concurrent with biogas recovery; improved removal of nutrients to meet the increasingly more stringent effluent standards.