Investigating and Improving Microbial Desalination Cell Performance Using Potassium Ferricyanide as a Chemical Catholyte

Abstract The crisis of obtaining drinking water and electrical energy from clean sources has been the primary focus of researchers seeking ecologically acceptable and cost‐effective alternatives. The microbial desalination cell (MDC) has shown to be one of the most cost‐effective and promising ways for creating electricity, cleaning sewage water, and naturally desalinating water. In this work, the AEM (Anion Exchange Membrane) was used in the anodic chamber, and potassium ferricyanide in the cathodic chamber as catholyte solution. Meanwhile, SEM (Scanning electron microscopy) analyses was used to define the resulting surface morphologies. This study gave an optimization model by Central Composite Design model, where all the variables affecting the microbial desalination cell (the initial concentration of COD (Chemical Oxygen Demand), the initial concentration of TDS (Total dissolved solids) and the operating time of the cell) were entered to obtain an equation for each response (electrical energy productivity, COD removal efficiency and water desalination efficiency) in addition to study the ANOVA (Analysis of variance) for each response and study the interactions of the variables with each other that affect the response. The variables were determined for the initial concentration of (COD) from (300‐1200 mg/L) and the initial concentration of (TDS) from (15–35 g/L) and the duration of the operating time was from (4–24 h) the maximum productivity was obtained. The power was 2.2 mW, and the maximum water desalination gave 42 %, and the optimum COD removal was 35 %. In addition to diagnosing the active sludge employed and defining the kind of bacteria controlling it, this research looked at the breakdown of the yield of ion exchange membranes, which had a negative impact on the desalination process and the productivity of electrical energy.