Multipurpose Polysaccharide-based composite hydrogel with magnetic and thermoresponsive properties for phosphorus and enhanced copper (II) removal

Adsorption is an effective approach for elimination of phosphorus from wastewater. Nevertheless, the environmental impact of adsorbent materials, the difficulty of recycling, and unsatisfactory utilization efficiency for disused adsorbents are still the limitations of adsorbent development and utilization. Herein, a novel polysaccharide-based composite hydrogel (HBPEC/SA/lignin hydrogel) containing 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC), sodium alginate (SA) and lignin, designed for phosphorus and enhanced Cu 2+ removal. The adsorption was pH dependent and was not affected significantly by co-existing anions (Cl − , NO 3 − and SO 4 2− ) except HCO 3 − . Interestingly, the captured phosphorus facilitated the adsorption of Cu 2+ , the Cu 2+ adsorption capability increased from 10.49 to 14.51 mg Cu/g by P-loaded adsorbent compared with adsorbent without P loaded. Particularly, the adsorbent achieved quick desorption due to its thermoresponsive. The shrunken hydrogel could be desorbed with only small amount of eluent and showed relatively high desorption efficiency. Altogether, HBPEC/SA/lignin hydrogel exhibited appealing application prospects in wastewater treatment.