N.A. Shehab, G.L. Amy, B.E. Logan, P.E. Saikaly
Journal of Membrane Science, volume 469, p. 364370, (2014)
Microbial desalination cell, Ion exchange resin, Electrodeionization, Brackish water desalination, Seawater desalination
A microbial desalination cell was developed that contained a stack of
membranes packed with ion exchange resins between the membranes to
reduce ohmic resistances and improve performance. This new
configuration, called a stacked microbial electro-deionization cell
(SMEDIC), was compared to a control reactor (SMDC) lacking the resins.
The SMEDIC+S reactors contained both a spacer and 1.4±0.2 mL of ion
exchange resin (IER) per membrane channel, while the spacer was omitted
in the SMEDIC-S reactors and so a larger volume of resin (2.4±0.2 mL)
was used. The overall extent of desalination using the SMEDIC with a
moderate (brackish water) salt concentration (13 g/L) was 90–94%,
compared to only 60% for the SMDC after 7 fed-batch cycles of the anode.
At a higher (seawater) salt concentration of 35 g/L, the extent of
desalination reached 61–72% (after 10 cycles) for the SMEDIC, compared
to 43% for the SMDC. The improved performance was shown to be due to the
reduction in ohmic resistances, which were 130 Ω (SMEDIC-S) and 180 Ω
(SMEDIC+S) at the high salt concentration, compared to 210 Ω without
resin (SMDC). These results show that IERs can improve performance of
stacked membranes for both moderate and high initial salt
concentrations.