Nutrient recovery by Donnan dialysis, Lee Blaney, UMBC

Details

Due to the uneven global distribution of phosphate deposits, current mining rates are concentrating the market, leading to greater economic and political volatility and impeding food security objectives in some regions. In addition, climate change is exacerbating the effects of nutrient pollution on drinking water quality, biodiversity, and fisheries. For these reasons, several countries have begun developing national phosphorus plans. We propose innovative Donnan dialysis systems as part of the strategy for achieving circular nutrient economies. Donnan dialysis processes are designed to induce electrochemical potential gradients across ion-exchange membranes, enabling selective recovery of ionic nutrients like phosphate and ammonium. This seminar will describe (1) the fundamental principles involved with Donnan dialysis, (2) opportunities to use seawater and reverse osmosis concentrates as alternative draw solutions, (3) application of Donnan dialysis to challenging wastes, such as coagulant-laden waste activated sludge and animal manure, and (4) the development of tube-in-tube Donnan dialysis reactors to enhance the rate of nutrient recovery and facilitate process scale up. The aggregate findings confirm the potential for advanced Donnan dialysis systems as feasible, scalable, and sustainable options for nutrient recovery from waste. Ultimately, these efforts contribute to development of circular nutrient economies that not only decrease the deleterious effects of nutrient pollution, but also provide food, economic, energy, and political security.

Lee received his BS and MS degrees in Environmental Engineering from Lehigh University. After completing his PhD in Civil Engineering at the University of Texas at Austin, he started as Assistant Professor at the University of Maryland Baltimore County, where he is now Professor. He also serves as Past President of the Association of Environmental Engineering and Science Professors (AEESP) and Executive Editor at the Journal of Hazardous Materials. He is a recipient of the ES&T James J. Morgan Early Career Award, the NSF Career Award, and the AEESP Award for Outstanding Teaching in Environmental Engineering and Science.