Abstract
This work presents a simplified mathematical model able to predict the performance of a microbial fuel cell (MFC) for the cathodic dechlorination of 2,4-dichlorophenol (2,4-DCP) operating at different cathode pH values (7.0 and 5.0). Experimental data from previous work were utilized for the fitting of the model. The MFC modelled consisted of two chambers (bioanode and abiotic cathode), wherein the catholyte contained 300 mg L−1 of 2,4-DCP and the anolyte 1000 mg L−1 of sodium acetate. The model considered two mixed microbial populations in the anode compartment using sodium acetate as the carbon source for growth and maintenance: electrogenic and non-electrogenic biomass. 2,4-DCP, its intermediates of the reductive process (2-chlorophenol, 2-CP and 4-chlorophenol, 4-CP) and protons were considered in the model as electron acceptors in the electrogenic mechanism. The global process rate was assumed to be controlled by the biological mechanisms and modelled using multiplicative Monod-type equations. The formulation of a set of differential equations allowed to describe the simultaneous evolution of every component: concentration of sodium acetate in the anodic compartment; and concentration of 2,4-DCP, 2-CP, 4-CP, phenol and chloride in the cathode chamber. Current production and coulombic efficiencies were also estimated from the fitting. It was observed that most of the organic substrate was used by non-electrogenic mechanism. The influence of the Monod parameters was more important than the influence of the biomass yield coefficients. Finally, the model was employed to simulate different scenarios under distinct experimental conditions.
Highlights
Chlorophenols (CPs) are phenol derivatives that contain one or more covalently bonded chlorine atoms
The main novelty points of the present work are the following: despite that we propose a simplified grey-box model, compared to some complex models previously reported, it could offer simplicity for design and operation purposes; both phenomena in the anode and cathode compartments are considered since the model includes the influence of all limiting reagents in both compartments; unlike most of the previously reported modelling studies, the final electron acceptor is not oxygen but the chlorinated species and protons; to the author’s knowledge, no previous modelling proposals have been reported when Bioelectrochemical systems (BES) are used for the removal of chlorophenols
This suggestes that only a low fraction of the acetate was oxidized via exoelectrogenic mechanisms, while the rest could be used under different non-aerobic pathways, such as methanogenesis or denitrification [33, 34]
Summary
Chlorophenols (CPs) are phenol derivatives that contain one or more covalently bonded chlorine atoms They have been widely used as herbicides, pesticides and disinfectants due to their antimicrobial properties, low biodegradability and environmental persistence. Still, their extended use has led to the contamination of ground and superficial water resources [1, 2]. One representative example of CPs is 2,4-dichlorophenol (2,4-DCP), which has been used in the chemical industry [3], mainly as a raw product for the fabrication of a wide spectrum of pesticides [2], and like most CPs, it presents toxicity and low biodegradability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
