Development of mathematical model for the prediction of zinc removal from a wastewater in microbial fuel cell

Zinc is used in the manufacture of various products such as alloys, paints, plastics, and rubber. A large amount of wastewater containing zinc is generated during the production of zinc metal. Wastewater containing zinc can cause several environmental issues. One of the methods for the removal and recovery of zinc from wastewater is the use of double-chamber microbial fuel cells. Mathematical modeling of a microbial fuel cell (MFC) as a useful tool is used for the evaluation of the effect of various operating parameters on its performance. Integration of bio-electrochemical kinetics with charge balance and mass transfer equations was performed in the developed model. The findings showed great agreement between the experimental results and the values obtained from the model in terms of zinc concentration as a function of time. In 24 hr, the zinc concentration was decreased from 1.82 mol/m 3 to approximately 0.2 mol/m 3 . It was also found that the pH increased from 7.4 to 8.2 with an increase in zinc concentration from 0 to 10 ppm. An increase in temperature can lead to an increase in the pH of the system. Furthermore, the potential decreased as temperature increased in the microbial fuel cells. The growth rate of biomass was lower at the beginning, but it was increased sharply between 9 hr and 24 hr. There was a considerable decrease in acetate concentration in the anode compartment where the rate of biomass growth was higher.