Development and Characterization of Bentonite/Hydroxyapatite-Based Chitosan Hybrid Composite for Effective Removal of Methylene Blue

Many dyeing industries release toxic effluents to water bodies that can severely affect human health, aquatic life, and other living organisms. Hence, the treatment of dyeing effluent is mandatory to protect the environment. Bentonite (BT) clay and hydroxyapatite (HA) ceramic material possess appreciable dye adsorption capacity. But BT and HA cause pressure drops during filtration due to their powder form. To overcome this problem and to enhance the dye adsorption capacity of BT and HA, the present study concentrates on the development of a hybrid clay-ceramic composite using chitosan (CS) biopolymer namely BTHACS composite. The developed BTHACS composite was employed for methylene blue (MB) removal. The highest dye adsorption capacity of 45.5 mg/g was obtained for BTHACS composite within 40 min contact time than the individual components (BT, HA, and CS). Various adsorption parameters, namely, initial MB concentration, contact time, pH, dosage, interfering ions, and temperature studies were performed under batch method. The nature of BTHACS composite and its MB adsorption were analyzed by FTIR, EDAX, and SEM analysis. The isotherm and kinetic studies were also investigated with different initial concentrations (80, 100, 120, and 140 mg/L) at 303, 313, and 323 K. Thermodynamic studies results confirm that the MB adsorption onto BTHACS composite was spontaneous, feasible, and endothermic in nature. The regeneration studies indicate that BTHACS composite has high reusable ability, and it can be recyclable upto 5 cycles. The field suitability results provide that BTHACS composite has a high potential for MB removal.

Automated summary

Many dyeing industries release toxic effluents that harm human health and the environment. In this study, a hybrid clay-ceramic composite using chitosan was developed for efficient removal of dyes. The composite showed high dye adsorption capacity and reusability, making it a promising solution for dye removal.