Efficient adsorption of congo red dye from aqueous solution using MWCNT/Chitosan-g-Poly (acrylic acid–crotonic acid) composite

This research studies the synthesis and evaluation of a new composite material, MWCNT/Chitosan-g-Poly (acrylic acid–crotonic acid), designed for the efficient removal of congo red (CR) dye from water. The composite was created through a graft polymerization technique and characterized by FTIR, XRD, and FE-SEM. These analyses confirmed the successful integration of MWCNTs and presence of numerous functional groups for adsorption. To understand the composite's performance, a series of batch experiments were performed to investigate the impact of contact time, pH, adsorbent dose, and initial dye concentration. Study was best described by pseudo-second model and Langmuir model (with maximum adsorption capacity of 14.13 mg g⁻¹) was the best fit for the equilibrium data and process was thermally spontaneous and exothermic. Overall, the synthesized material showed good adsorption potential for dye removal from water.