The desalination performances of capacitive deionisation (CDI) and membrane capacitive deionisation (MCDI) cells have been investigated under different working voltages and feed concentrations, and assessed in terms of adsorption capacity and specific energy consumption.
Capacitive deionisation (CDI) is a state-of-the-art water desalination technology, in which ions are removed using capacitive adsorption.
In this Chinese work, graphite cloths were used as electrode materials to fabricate the CDI cell, and the ion-exchange membranes were introduced in the CDI cell to assemble the membrane capacitive deionisation (MCDI) module.
The desalination performances of the CDI and MCDI cells were investigated under different working voltages and feed concentrations, and assessed in terms of adsorption capacity and specific energy consumption.
The experimental results indicate that the introduction of the ion-exchange membranes can effectively prevent the 'co-ion' effect in the CDI, and the current efficiency of MCDI was up to four times that of CDI.
Under these experimental conditions, the adsorption capacity of MCDI is much higher than that of CDI. In addition, its specific energy consumption is dramatically reduced, indicating the comprehensive economic advantage of MCDI technology.
