Desalination of brackish water using a microbial desalination cell: Analysis of the electrochemical behaviour

Abstract

A microbial desalination cell (MDC) is a microbial fuel cell (MFC) integrated with an electrodialysis (ED) cell in the same device to simultaneously treat wastewater, desalinate brackish or seawater, and produce electric energy. Most previously reported studies used oxygen reduction as the primary cathodic reaction. In contrast, we have explored brackish water desalination (7 g L−1) and energy production using a laboratory MDC system (cross-section 100 cm2, batch mode) and ferricyanide as the catholyte. Furthermore, a rational explanation of desalination performance when using a catholyte is presented, and, additionally, the impact of producing electrical energy on desalination performance is discussed. Interestingly, conductivity variation in the saline chamber can be used to predict electrochemical performance. In summary, this study provides the basis for the development, design, and optimisation of low-energy desalination using MDC technology.