Hydrogels for anion removal from water

Abstract

Anionic pollutants are becoming more and more prevalent in the hydrosphere due to the extensive use of industrial raw materials. This can lead to a variety of problems that impact both aquatic and terrestrial life. To date, many kinds of materials have been reported for anion removal, including activated carbon, coagulants, zeolites, chitosans, mineral clays, hydrogels, and microorganism adsorbent materials. Among them, hydrogels have garnered attention for removing unwanted anions from water due to their unique advantages, including the fact that they are environmentally friendly to water, produce little to no secondary contamination, are easily recycled, and can be operated without the need for complicated equipment. This mini-review highlights recent work on hydrogels designed to remove anions from aqueous media. The discussion is categorized according to gel type, namely non-covalently assembled hydrogels, covalently crosslinked hydrogels, and hybrid hydrogels.