Effect of Solution Ph on Activated Carbon Adsorption

The effect of solution pH on adsorption must be considered in conjunction with the effects of activated carbon and the adsorbate (solute). Solution pH controls the degree of dissociation of acidic or basic compounds; when the pH reaches a certain range, these compounds dissociate, affecting their adsorption. Solution pH also affects the solubility of the adsorbate (solute) and the charge of colloidal adsorbates (solutes). Since activated carbon adsorbs hydrogen and oxygen ions from water, it affects the adsorption of other ions.

The effectiveness of activated carbon in adsorbing organic pollutants from water generally decreases with increasing solution pH. Adsorption is difficult above pH 9.0, and the effect is better at lower pH values. In practical applications, the optimal pH range should be determined experimentally.