Thermodynamic approach to simulate current densities of energy-harvesting microbial electrochemical systems fed with human urine. (June 2022)

• Record Type: Journal Article
• Authors: Prudente, Mariano; Massazza, Diego A.; Busalmen, Juan P.; Romeo, Hernán E.
• Is Part Of: Bioresource technology reports. Volume 18(2022)
• Publication Date: 2022-06
• Subjects: Microbial electrochemical systems -- Urine -- Bio-energy -- Simulation -- Thermodynamics; Biomass energy -- Periodicals; Biotransformation (Metabolism) -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Waste products as fuel -- Periodicals; Waste products as fuel; Organic wastes; Factory and trade waste; Biotransformation (Metabolism); Biomass energy; Agricultural wastes; Periodicals; Electronic journals; 662.88
• DOI: 10.1016/j.biteb.2022.101058
• Languages: English
• ISSNs: 2589-014X

Abstract

Abstract: Different theoretical models have been addressed to simulate electricity generation of microbial electrochemical systems (MESs) fed with a variety of organics. In the case of urine-fed MESs (u-MESs), the lack of input parameters to feed current bio-physical models has somehow restrained their theoretical approach. This study introduces a model, based on microbial energetics, to simulate current generation of u-MESs without the need of resorting to parameters typically used as simulation entries in bio-physical approaches (e.g., maximum substrate-utilization rates (qmax ), Monod half-saturation coefficients ( K S )). The strategy consisted in linking the catabolic energy density available in the urine medium to the specific electro-active microbial growth-rate, the latter calculated from metabolic thermodynamics (Gibbs free-energy changes for the catabolic/anabolic reactions, and Gibbs energy dissipation). Calculated growth rates were used to compute specific substrate-utilization rates, the effective flux of electrons into the anode biofilm and the resulting current densities as a function of urine concentration. Graphical abstract: Unlabelled Image Highlights: Current densities of urine-fed MESs were simulated from bacterial energetics. Electro-active microbial growth rates were computed from metabolic thermodynamics. Growth rates were linked to substrate-utilization dynamics to calculate current densities.