An investigation of the impact of fouling agents in capacitive and membrane capacitive deionisation

Abstract

The effect of organic fouling on both capacitive deionisation (CDI) and membrane capacitive deionisation (MCDI) was studied using two model foulants, the sodium salt of alginic acid and humic acid. Fouling of the activated carbon electrodes in the CDI cell was significant. The salt adsorption fell to 75% and the charge efficiency to 90% of their initial values after 18 cycles of operation with 0.5 mM CaCl 2 and 60 mg L −1 of sodium alginate. Similarly, the salt adsorption fell to 70% and the charge efficiency to 65% of their initial values after 18 cycles of operation with 60 mg L −1 of humic acid. The effect on MCDI was much more limited with these two foulants. The ability to clean the CDI..