Chitosan entrapped microporous activated carbon composite as a supersorbent for remazol brilliant blue R

Abstract

In this work, we synthesized a chitosan-activated carbon composite (Cs–C) using sodium tripolyphosphate (STTP) as a crosslinker. The Cs–C was characterized through Fourier transform infrared, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and the pH point of zero charge for the physicochemical, structural, and morphological analyses. The material was subjected to the adsorption of Remazol Brilliant Blue R (RBBR) dye. The effects of the solution pH, adsorbent dose, contact time, temperature, and dye concentration were examined. The equilibrium data was described well by the Langmuir isotherm model with a coefficient of determination (R²) value of 0.9994 and chi-square value of 6.94. At near-neutral pH, with a contact time of only 60 min at room temperature, the material showed an extremely high adsorption capacity of 540.3 mg g⁻¹ which is much higher in contrast to all the previously reported materials. The kinetics of uptake was well-described by the pseudo-second-order model chemisorption model. Evaluation of the thermodynamic parameters reflected the spontaneous, endothermic and entropy-driven nature of the adsorption.