Cellulose-based hydrogel beads derived from wastepapers: application for organic dye adsorption

Some adsorbent hydrogels made of natural polymeric materials have not yet met the needs for a high level of wastewater purification. In the present study, a novel and environmentally friendly process is described for the production of natural cellulose-based metal oxide nanoparticle hydrogel beads. Recyclable adsorbent components include wastepaper-derived cellulose fiber, metal oxide nanoparticles and polyvinyl alcohol was synthesized, the WCF/PVA MO NP hydrogel beads were synthesized by using cross-linking agents (Ca 2+ , boric acid and NaCl), and were analyzed by evaluating their ability to remove the acid red 18 (AR18) from aqueous solution. The WCF/PVA MO NP was characterized by FESEM, XRD, EDX, BET, and FTIR. The results revealed that the metal oxide nanoparticles distributed on external and internal channels of the 3D fiber network of WCF with strongly covalent/non-covalent cross-linking bonds would facilitate mass diffusion and enhance the interaction between AR18. The results shown that more than 87.62% of AR18 was removed and adsorption capacity was 88.65 mg·g −1 under optimized conditions ([AR18]: 10 mg·L −1 ; [adsorbent]: 0.55 g·L −1 ; pH: 3; Time: 46 min). Results shown that the adsorption kinetics fit the pseudo-second-order model (0.99), and the adsorption isotherms fitted to Langmuir isotherm model (0.99). Graphical abstract