(470e) Electrochemical Routes for Nutrient Recovery from Sludge

Waste activated sludge (WAS) is the solid residue obtained after solid-liquid separation in the primary, secondary, and tertiary wastewater treatment processes [1]. The production of waste activated sludge (WAS) from wastewater treatment processes is rapidly increasing. In 2011, global WAS generated was at 2 billion tons and a five-fold increase is expected by 2050 [2]. Disposal of WAS is mainly to landfills due to the energy and capital-intensive nature of other methods such as pyrolysis, gasification, and digestion.

WAS contains a wide range of organic compounds as well as valuable nutrients such as phosphorus and nitrogen which can account for up to 4% and 9% of dry sludge, respectively [3]. The leachate from landfills can release these nutrients into the environment, raising environmental concerns. Therefore, recovering nutrients from WAS presents a significant opportunity towards a circular economy.

Botte's group has been exploring novel electrochemical methods for nutrient recovery from sludge [4]. This presentation will focus on the group's advances in electrocatalysis using transition metal electrodes for nutrient recovery and the effects of parameters such as pH, temperature, and applied cell potential. Since sludge treatment accounts for a sizable portion i.e., 50 to 60% of wastewater treatment plant operational costs, WAS nutrient recovery could also provide economic benefits. This research highlights the potential for electrochemical approaches to address environmental concerns, improve resource efficiency and provide a sustainable solution for sludge management.

[1] Fytili D, Zabaniotou A. Renewable and sustainable energy reviews. 2008 Jan 1;12(1):116-40.

[2] Pham TP, Kaushik R, Parshetti GK, Mahmood R, Balasubramanian R. Waste Manag. (2015). Apr;38:399-408. doi: 10.1016/j.wasman.2014.12.004. Epub 2014 Dec 30. PMID: 25555663.

[3] Wei Bi, Yiyong Li, and Yongyou Hu. Bioresource technology 166, (2014): 1-8. doi: 10.1016/j.biortech.2014.04.092

[4] Jafari, M., Botte, G.G. J. Appl. Electrochem. 51, 119–130 (2021). https://doi.org/10.1007/s10800-020-01481-6