Fabrication of magnetic particles imprinted cellulose based biocomposites for chromium(VI) removal

The present study was focused on Cr(VI) removal using eco-friendly materials like cellulose (Cel), hydrotalcite (HT), hydroxyapatite (HAp) and their composite forms. The cellulose/hydrotalcite (CelHT) and cellulose/hydroxyapatite (CelHAp) composites were synthesized by dispersing HT and HAp individually in cellulose polymeric matrix. To enhance the Cr(VI) sorption capacity (SC) and easy separation, cellulose supported magnetic composites namely iron-oxide coated cellulose/hydrotalcite (Fe₃O₄@CelHT) and cellulose/hydroxyapatite (Fe₃O₄@CelHAp) were synthesized by in situ fabrication method. The different adsorption influencing parameters like contact time, pH, co-ions, dosage, initial Cr(VI) concentration and temperature were optimized for maximum Cr(VI) sorption. The structure and morphology of cellulose supported magnetic composites were analyzed using FTIR, BET and SEM with EDAX analysis. The obtained equilibrium value was interpreted with Freundlich and Langmuir isotherms. The suitable Cr(VI) uptake mechanism for cellulose supported magnetic composites was demonstrated. The values of thermodynamic parameters helps in the prediction of nature of Cr(VI) sorption process. The suitability of these magnetic cellulose supported composites was tested at field conditions by collecting chromium contaminated water.