Synthesis and surface gel‐adsorption effect of multidimensional cross‐linking cationic cotton for enhancing purification of dyeing wastewater

Abstract

AbstractBACKGROUNDDyeing wastewater has caused serious pollution of aquatic environments, and adsorption is one of the most commonly used water‐purification methods with selection of suitable adsorbents being the key factor. These factors motivated us to develop new, more efficient adsorbents to purify dyeing wastewater.RESULTSA surface cross‐linking co‐polymerization of triallylmethylammonium chloride (TAMAC) and grafting cotton with unsaturated bonds (G‐cotton) was designed to obtain multidimensional cationic cotton adsorbent (PT‐cotton) with a high cationic degree of substitution of 0.129. A surface gel‐adsorption effect of the multidimensional cationic construction on cotton surface occurring during PT‐cotton adsorption was discovered resulting in the PT‐cotton having an ultrahigh adsorption capacity for purifying dyeing wastewater. Compared to the untreated cotton, the adsorption capacity of the PT‐cotton was 1344.10 times higher. Compared to the widely used activated carbon, the adsorption capacity of the PT‐cotton was 145.31 times higher, and it was 11.05 and 7.25 times higher, respectively, than that of the similar G‐cotton and polycationic cotton (PF‐cotton) reported in our previous contribution. When PT‐cotton materials were used to fill filter columns, the dye solution flowing through the filter columns immediately became clear, and the dye removal percentage for the PT‐cotton filters reached 96.9%, which was clearly better than that of the activated carbon filter (26.2%). Moreover, the per‐unit amount of water purification from filtering purification of a dye solution using PT‐cotton was 7.02 times higher than that using PF‐cotton.CONCLUSIONSObtained PT‐cotton has a greater potential for application in the purification of dyeing wastewater than the existing adsorbent materials. © 2018 Society of Chemical Industry