Using activated carbon electrode in electrosorptive deionisation of brackish water

The electrosorptive deionisation process has been investigated to develop the technology into a system for desalination. Experiments have been conducted in a reactor system and it has been found that the activated carbon has some deionisation capacity due to its very high adsorption capacity and conductivity, so it can be used as an alternative electrode material. Surface modifications have been made to the activated carbon material, including alkaline treatment and loading of titanium dioxide nanoparticles. The specific surface areas (BET), average pore size and total pore volume were analysed by surface area and porosity analyzer. The modified electrode material demonstrated enhanced electrosorption capacity and reduced physical sorption at the pores, so desorption is more efficient. An innovative approach for desorption of the saturated activated carbon electrodes has been tried using ultrasonic vibration and increased temperature, the results of regeneration in water, aided by ultrasonic at 20°C and 50°C are presented as well. Cyclic voltammetry experiments at various scan rates were conducted using a potentiostat to analyse the electrical double-layer capacitance of the activated carbon materials. This preliminary study demonstrated that activated carbon granules have the potential to be cost-effective electrode materials for desalting brackish water. The improvement of the electrosorption efficiency can be achieved by surface modification by chemicals and metal oxide nanoparticles such as TiO2.