A novel graphene oxide functionalized hydrocalumite/cellulose composite for the selective and simultaneous removal of tetracycline and Cr(VI)

Tetracycline antibiotic and hexavalent chromium removal from the wastewater is crucial for preventing future environmental trouble. This study aimed to develop an eco-friendly biocomposite made from an enhanced graphene oxide-functionalized hydrocalumite/cellulose composite for co-adsorbative removal of TC antibiotic and toxic Cr(VI). The synthesized GO@CellHC composite was characterized using various microscopic techniques. The GO@CellHC composite possessed the superior removal for TC and Cr(VI), achieving 27.4 and 42.6 mg/g in single systems, and 24.8 and 39.6 mg/g in binary systems, all within 40 min. In pH results, the maximum removal was observed at an acidic pH of 3 for Cr(VI) and 5 for TC, respectively. The co-ions results demonstrated that the composite efficiently removed both pollutants, except in the presence of PO₄^3- and CO₃^2-. The Langmuir isotherm indicated the strongest adsorption capacity and favored both systems. Thermodynamic studies revealed that the adsorption of both systems onto the GO@CellHC composite removes TC and Cr(VI) by endothermic and spontaneous system. Kinetic results demonstrated that TC adsorption showed a higher rate constant k₂ (single: 0.01676 min^-1 and binary: 0.0138 min^-1) compared to Cr(VI) adsorption (single: 0.01478 min^-1 and binary: 0.01007 min^-1). The GO@CellHC composite retained more than 80 % after three cycles, and field results suggesting that the biocomposite can be utilized for the removal of binary water pollutants.