Influence of surface charge and textural properties of carbon electrodes on nitrate ion removal by electroadsorption

It is shown how to remove nitrate ions from aqueous solution by electrosorption in a way that has a low environmental impact and is energy saving. In order to elucidate adsorption/desorption mechanism of nitrate ions, ion removal using flow through capacitor and cyclic voltammetry measurements were investigated. Characterization of suitable electrodes for electroadsorption was determined. The static attraction by surface charges of carbon electrodes had a profound effect on adsorption of nitrate ions. It is difficult for nitrate ion to desorb from the electrode, therefore an electrode with pHPZC (point zero of charge) of a weak acid is appropriate. Due to the overlapping effect of diffusion layers in pores, it is thought that large mesopores (>20 nm) and the voids between particles are effective in dilute solution for nitrate ion removal.