Nylon 6,6 based fibrous composite: preparation, characterization and its utilization for the removal of hazardous Cr(vi) from aqueous solution

Abstract

This study reports the synthesis of nylon 6,6-zirconium(IV)selenite (N6/ZS) fibrous composite as a promising adsorbent for the removal of Cr(VI), a known carcinogen and hazardous heavy metal. The formation of the N6/ZS composite was confirmed by Fourier transform infra-red spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). The composite showed appreciable adsorption of Cr(VI). In addition, batch adsorption studies concerning the effect of pH, contact time, initial Cr(VI) concentration and temperature were performed. The monolayer adsorption capacity calculated from the Langmuir model for N6/ZS was found to be 59.171 mg g⁻¹ at 50 °C and the negative free energy change confirms the adsorption of Cr(VI) as a spontaneous and endothermic process. The adsorption rate was considerably fast and followed pseudo-second-order kinetics suggesting that the adsorption mainly consisted of chemisorption. The intra-particle diffusion model indicated that intra-particle diffusion was not only the rate limiting step and hence, the adsorption of Cr(VI) was chemical in nature. Also, the adsorbent could be effectively regenerated and showed good reusability. The facile synthesis and the robust adsorption performance of this fibrous composite can reveal new avenues for the removal of environmental hazards.