A microbially catalyzed anode and cathode microbial electrosynthesis system for efficient metformin removal and volatile fatty acid production

Abstract

The removal of different pharmaceuticals and personal care products from surface water is crucial. This study focused on the removal and transformation of metformin (MTF), an emerging contaminant in aqueous solutions using a dual bioanode (BIND) and biocathode (BICD) microbial electrosynthesis system. Successful biodegradation of MTF (91%) was achieved within 120 h with improved bioelectrochemical performance. The current density (−849 mA/m2) with drug loading at 0.5 ppm was 10.3, 7.6, and 2.4 times higher than that of the control, 0.1 ppm, and 0.3, ppm, respectively. Volatile fatty acids (VFA) production also improved with excellent acetate, propionate, and butyrate production at both BIND and BICD. Liquid chromatography Mass spectrometry (LC-MS) studies indicated improved mineralization with more MTF bioproducts. MTF regulated the microbial flora through enrichment of the electroactive phyla Proteobacteria and Bacteroidetes. This study provides a new perspective for the use of dual biocatalyzed microbial electrosynthesis systems in bioremediation research.