Assessment of the electricity generation, desalination, and wastewater treatment efficiencies of a microbial desalination cell operating with electrolyte dilution as pH control measure

Abstract

In this study, the dilution of anolyte and catholyte as a pH control measure in a newly developed microbial desalination cell (MDC) was explored. Also, the effects of dilution on the newly developed MDC’s electricity generation, desalination and wastewater treatment efficiencies were assessed against a three-chamber MDC which used potassium phosphate buffer for pH control. On the average, the newly developed MDC exhibited a lower buffer capacity (pH change of 1.73 ± 0.06) as compared to the relatively higher buffer capacity (pH change of 1.49 ± 0.07) of the three-chamber MDC. However, the newly developed MDC produced a higher desalination efficiency of 50.01% compared to the 46.66% produced by the three-chamber MDC and a higher power density of 0.62 ± 0.13 W/m³ than the 0.35 ± 0.70 W/m³ produced by the three-chamber MDC. It’s COD reduction efficiency (63.21%) was also higher than the 42.81% produced by the three-chamber MDC.