Performance Assessment of Bio-Cathode Microbial Desalination Cell for Simultaneous Desalination and Wastewater Treatment

Abstract

Under fresh water shortage conditions, polluted water treatment and brackish water desalination could be a correct defense mechanism in this situation. In the present study, Microbial Desalination Cell (MDC) performance was tested on a laboratory scale to investigate the desalination process and wastewater treatment. The experiments were designed in a three-chamber reactor using activated sludge as bio-catholyte and synthetic wastewater in four different hydraulic retention times and 35 g/l NaCl concentration in two functional mods (batch & continuous). According to the results, maximal salt removal and EC reduction rate of about were obtained in continuously fed mode, respectively. The anolyte pH in both batch and continuous modes dropped from 7 to 6.47 and 6.48 respectively. The chemical oxygen demand (COD) removal values in the continuous mode were 61 and 65% in the anolyte and catholyte respectively, higher than those of fed-batch MDC. Moreover, the result of examining indicated the statistical relationship between system efficiency (salt removal, COD removal, and EC reduction rate) and hydraulic retention time and also between system efficiency and hydraulic flow. On the other hand there is a significant level (Sig< 0.05) which represents direct relationship between the above parameters.

Keywords

• activated sludge
• bio-fouling
• bio-cathode
• hydraulic retention time
• microbial desalination cell