ELECTROCHEMICAL METHOD FOR THE REMOVAL OF ARSENATE FROM DRINKING WATER

摘要

The present invention provides an electrochemical method for the removal of arsenate from drinking water, wherein the arsenate is removed by adsorption of metal hydroxide, formed by 'in-situ' anodic oxidation. The electrochemical method, of the present invention, for the removal of arsenate from drinking water, obviates the drawbacks of the commonly used physico-chemical treatments processes such as lime softening, sorption techniques and membrane techniques. The electrochemical method consists of an electrochemical cell fitted with an anode of mild steel or aluminium plate and stainless steel cathode with an inter-electrode distance of 0.5 to 1.5 cm. Drinking water containing 0.5 to 3.0 mg/l of arsenate at a pH in the range of 3-10 and at a temperature between 20-60° C. is electrolysed at anode and cathode current densities between 0.05-0.2 A.dm^-2. The iron hydroxide/aluminium hydroxide formed from the anode during electrolysis adsorbs the arsenate present in the water and settles at the bottom. The removal efficiency of this method is up to 98%.