Efficiency of microbial desalination cells in treating wastewater, desalinating saltwater, and generating bioelectricity in Bangladesh

Abstract

Desalination ensures the provision of potable water to those living in coastal areas, thereby guaranteeing access to safe drinking water. Urbanization and industrialization pollute natural water sources with untreated and partially treated wastewater. International researchers have been searching for cost-effective and environmentally friendly solutions to the above-highlighted difficulties. Developed countries efficiently treat wastewater and desalinate seawater at a minimal expense while reducing nonrenewable energy consumption using microbial desalination cells (MDCs). The use of ion exchange resin-based MDCs is expected to remove salt from seawater and produce bioelectricity. This research aimed to build MDCs with two types of electrodes and determine their efficiency in the desalination of seawater and generation of bioelectricity while treating wastewater. Results showed that MDCs with Zn–Cu and carbon fiber cloth electrodes effectively treated textile and tannery effluents. Calculations encompassed several parameters such as current, voltage, power, current density, power density, desalination efficiency, rate, COD reduction, and TDS reduction. MDCs containing Zn–Cu electrodes generated energy and removed 65% COD and 33% TDS while treating wastewater. The most efficient MDC (Zn–Cu electrode-based MDC) reduced the salinity of seawater by 85%. At the same time, using the carbon fiber cloth electrode-based MDC, about 78% salinity could have been reduced from seawater. The maximum and minimum desalination rates for this experiment were 1.24 and 1.096 ppt per day, respectively. MDCs efficiently desalinated saltwater, treated wastewater, and generated bioelectricity. Therefore, for countries such as Bangladesh, this method is economically viable.