Microbial desalination technology offers a promising platform for salt removal processes and for the recovery of ionic compounds. In terms of operation, systems without potential control (microbial desalination cell, MDC) and applying anode potential control (microbial electrolysis desalination cell, MEDC) can be primarily implemented. In this study, a comparative assessment of the different operational modes is carried out by using acetate-fed mixed culture MDC and MEDC reactors for NaCl removal (with 35 g L−1 initial concentration) in three-chamber setup. Desalination efficiency, kinetics, as well as the occurring electrochemical losses are evaluated.
In addition, ion exchange membrane (IEM) performance and stability are addressed. It was found that MEDC mode led to faster desalination and better NaCl removal (~ 45 %) during 24 h long batches, compared to MDC (40.3 %), thanks to the ~12 % higher (j = 12 ± 5 A m−3) and more consistent current density generated. Severe diffusional losses occurred in both systems, leading to ~80 % decrease in desalination rate after 24 h of operation. In addition, IEM ionic conductivity was significantly reduced after 40 d long employment. Future research needs and directions are highlighted for system performance enhancement.