Alginate-based polysaccharide beads for cationic contaminant sorption from water

Massive amounts of agricultural and industrial water worldwide are polluted by different types of contaminants that harm the environment and impact human health. Removing the contaminants from effluents by adsorbent materials made from abundant, inexpensive polysaccharides is a feasible approach to deal with this problem. In this research, alginate beads combined with two types of cellulose, starch or xylan were synthesized. Their average diameters in air- and freeze-dried conditions were assessed by optical microscopy. Differences in morphology were observed by scanning electron microscopy. Their capacity for water uptake, their sorption capabilities for a model cationic pollutant and their charge density was investigated in relationship to their composition and their surface characteristics. Their interaction with water was evaluated using low-field NMR spectroscopy. It was found that nanocrystalline cellulose added the most to the beads’ sorption capacity for cationic contaminants while xylan admixture created the beads with the highest water sorption after lyophilization.