(Invited) Electrified Resource Recovery Via Nutrient Reduction from Wastewater

Abstract

Significant anthropogenic activity has been crucial in maintaining global population growth by fixing macronutrients required for crop growth into the soil. Two of these macronutrients – nitrogen (N) and phosphorus (P) – are also responsible for detrimental environmental impact via eutrophication. This eutrophication is driven by excess application of inorganic fertilizer products and organic animal waste from animal feeding operations; components that eventually end up in natural bodies of water due to erosion and leaching. Furthermore, in digester-equipped municipal wastewater treatment facilities, elevated N and P levels in the liquid stream recycled to the head of the facility drives increased resource consumption for nutrient reduction: chemicals for P management and energy for N management. Therefore, opportunities exist to simultaneously minimize environmental impact and energy consumption through improved nutrient management techniques, thus addressing issues at the Food-Energy-Water nexus.Various electrochemical techniques are in early-stage development for an electrified approach to recovering these nutrients and reducing their environmental impact including bio-electrochemical1, electro-deionization2 and electrocoagulation3 approaches. This talk will focus on the indirect electrochemical approach: oxygen/water reduction to promote favorable pH conditions at the electrode surface for nutrient precipitation. Preliminary work4,5 has shown the viability and utility of this approach for nitrogen and phosphorus reduction in synthetic wastewater simulating animal waste. Additional findings describing the impact of competing ions, mass transport and electrolyte thermodynamics on nutrient reduction and recovery will be presented at the conference. An outlook on how this approach impacts energy consumption within the context of decarbonization of the manufacturing sector will also be discussed.References Y. Lei et al., ACS Sustain. Chem. Eng., 7, 8860–8867 (2019).Y. Bian, X. Chen, L. Lu, P. Liang, and Z. J. Ren, ACS Sustain. Chem. Eng., 7, 7844–7850 (2019).L. Kékedy-Nagy et al., J. Am. Chem. Soc., 142, 18844–18858 (2020).Z. Belarbi and J. P. Trembly, J. Electrochem. Soc., 165, E685–E693 (2018).Z. Belarbi, D. A. Daramola, and J. P. Trembly, J. Electrochem. Soc., 167, 155524 (2020).