Effect of Pretreatment of Carbon Based Electrodes in Their Adsorption Performance in Capacitive Deionization

Capacitive deionization (CDI) is a novel technology that removes ions from water using electrical field and electro-adsorption. CDI offers to be an energy efficient and less chemical residue producing alternative to contemporary deionization technologies such as reverse osmosis or multistage flash in case of low saline water. Carbon based porous electrodes have been a popular choice as electrode in CDI due to their high surface area and inertness in low applied voltages. Recent researchers have focused on improving the adsorption capacity of carbon based electrodes through various surface treatment processes. The focus of recent work is to improve key parameters such as the electrical double layer effect, porosity, and wettability of electrodes for increased adsorption capacity. Here in this work, electrodes made of carbon aerogel and commercially available carbon blocks were used and their respective adsorption performances in CDI applications were compared to study the effect of surface treatment with acetone and nitric acid separately. The cumulative effect of carbon surface treatment with both acetone and nitric acid was also studied.