Water-soluble functional polymers in conjunction with membranes to remove pollutant ions from aqueous solutions

This review places special emphasis on the study of water-soluble polymers that contain one or more amine, amide, carboxylic acid, hydroxyl, phosphonic acid, quaternary ammonium salts, and sulfonic acid groups at the backbone or side chain and their ability to remove ion pollutants from aqueous solutions. In additional, this review differentiates between different experimental procedures, including the liquid-phase polymer based retention (LPR) technique that combines the use of water-soluble polymers and ultrafiltration membranes, as well as arsenic removal by combining LPR and electrocatalytical oxidation (EO) techniques. EO and LPR can also be coupled off-line to remove arsenic inorganic species from aqueous solutions. A variety of studies show that the functional groups on the polymer and the solution pH have a marked effect on ion removal.