Patent ID: 7311842

Claim:
A process for treating a contaminated aqueous solution to remove one or more anionic contaminants therefrom, comprising: a. contacting the contaminated aqueous solution with a lignocellulose-based anion-adsorbing medium (LAM), wherein the LAM has been formed by the steps of: i. dissociating cations selected from the group consisting of Fe or Al, from their counterions by adding a chemical compound containing said cations to water and acidifying; ii. pellitizing a lignocellulose having hydroxyl groups (—OH); iii. combining the cations with said lignocellulose hydroxyl groups (—OH) by bringing the lignocellulose into contact with the solution of step (i) and incubating; and iv. catalyzing the chemical replacement of the lignocellulose hydrogens (H) of the hydroxyl groups of the lignocellulose with the cations to produce the LAM with a positive charge by exposing the lignocellulose of step (iii) to an alkaline fixing agent; b. contacting the LAM with the contaminated aqueous solution to enable the contaminants to be retained at the Fe or Al combined with the lignocellulose; and c. recovering a treated aqueous solution with reduced content of the one or more anionic contaminants.