Hexavalent chromium-reducing microbial fuel cell modeling using integrated Monod kinetics and Butler-Volmer equation

Abstract

Dynamic computational model development for the reduction of hexavalent chromium [Cr(VI)] in a microbial fuel cell (MFC) is demonstrated in this work. The model incorporates Monod kinetics with Butler-Volmer equation to describe the performance of Cr(VI)-reducing MFC. Successful parameter estimation and validation were demonstrated using the results obtained from a dual-chambered MFC operated at different Cr(VI) initial concentrations. In addition, it was shown that it is important to optimize the electrogen concentration since it affects not only Cr(VI) reduction but the time it takes to achieve maximum output voltage. Also, the optimization of substrate concentration was demonstrated in order to improve both the reduction of Cr(VI) and power output. This study presents an initial step into determining the operational conditions of metal-reducing MFCs without conducting much of lab-work. The model is easy to implement and may be suitable in the design and operation of metal-reducing MFCs.