Microbial desalination cells with ion exchange resin packed to enhance desalination at low salt concentration

High internal resistance is one main obstacle for the application of microbial desalination cell (MDC) at low salt concentration. To enhance desalination and electricity production of MDC at low salt concentration (<0.7 g/L NaCl), ion exchange resin (IER) was packed in a desalination chamber. The desalination profiles followed pseudo-first-order kinetics. For initial NaCl concentrations of 700 and 100 mg/L, compared to MDC without resin, the kinetic constant increased 2.5 times to 0.152 h−1 and 3.9 times to 0.363 h−1, respectively, while infinite concentration decreased 6.6 times to 7.13 mg/L and 2.6 times to 10.6 mg/L. On the other hand, the current and power density also increased with IER packing. The improved performance was due to the better transfer capacity and lower internal resistance with IER packing. The low effluent salinity would also benefit for the following deeper desalination process.

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► IER was packed in MDC to enhance desalination at low NaCl concentration.
► MDC packed with IER showed higher kinetic constant and lower infinite concentration.
► IER also enhanced electricity production and power density of MDC.
► The better performance was due to better transfer capacity and lower resistance.