Anaerobic Treatment of High Fat Content Wastewater in Microbial Electrochemical Cells

Abstract

Microbial electrochemical cells (MECs) are devices in which anaerobic treatment of wastewater can occur in the anode chamber, where anode-respiring bacteria oxidize fatty acids produced from fermentation of waste organics to produce an electrical current. MECs are best suited for high-strength industrial wastewater streams, rather than dilute domestic wastewater streams. We have evaluated the possibility of using MECs for treatment of rendering wastewater, which contains high concentrations of fats (and often also proteins). We first conducted biochemical methane potential (BMP) tests to determine the anaerobic biodegradability of rendering wastewater (COD concentrations of ~7000 mg/L), and to determine optimum organic loading rate (relative to biomass concentration). Using the optimum conditions, we then conducted batch MEC studies to determine maximum current densities that could be produced, as well as the COD removal and conversion efficiencies. Maximum current densities of up to 2.5 A/m 2 were produced, while COD conversion to electrical current ranged between 70-80%. Our studies indicate that MECs could become suitable for treatment of high fat content wastewater streams.

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Identifiers

DOI

10.1149/ma2019-02/50/2219

Journal

ECS Meeting Abstracts

Year

2019