Dynamical Analysis of Microfluidic Microbial Electrolysis Cell via Integrated Experimental Investigation and Mathematical Modeling

The present study deals with the feasibility of a microfluidic microbial electrolysis cell (MEC) as an efficient biohydrogen generator for medical usage for the first time. The evaluation of nickel in microfluidic MEC as an alternative for conventional electrodes indicates successful performance in the improvement of bioenergy production. The maximum biohydrogen production rate and produced power density of 2.2 μW cm−2 and 1.4 μl H2 μl substrate−1 day−1 were obtained, respectively. It is considered a promising technology for medical usage due to the following factors: significant biohydrogen generation, low consumption of expensive materials, simple construction, and utilization of human excreta. In addition, the study established a novel integrated modeling approach with chemotaxis phenomena. This was to interpret the distribution mechanism of the suspended microorganisms in anolyte and/or their attachment to anode surface to extend the biofilm, and improve the performance of previous models. The verification of integrated modeling approach with chemotaxis phenomena reveals that the significant configurations of the present model in bacteria chemotaxis mechanisms are compatible with real conditions. Microfluidic MEC performance was assessed by analyzing the dynamic behavior of the anolyte and biofilm, substrate variation, biohydrogen production rate and influences of applied potential on the biofilm, and anolyte's features.