Dewaxed honeycomb as sustainable nanocomposite for the decontamination of toxic heavy metal from water

Abstract

To achieve sustainability, the waste produced by various sources must be transformed into economically viable materials. Herein the honeycomb incorporated with polypyrrole (DWHC@Ppy) was used as a waste material and converted into an adsorbent to remove toxic Pb2+ and Cd2+ from aqueous media. The material was thoroughly characterized by XRD, FTIR, SEM-EDX, and TEM. The process parameters were appraised via batch mode and the optimized parameters were found to be 0.5 g L-1; 50 min; 50 mg/L; pH 6. The non-linear isotherm and kinetic modeling were confirmed well by pseudo-second order and Freundlich models respectively suggesting heterogeneous adsorption. The maximum adsorption capacity Qm was found to be 731.08 and 642.59 mgg−1 for Pb2+ and Cd2+ and it decreased with an increase in temperature (298–313 K) implying the process to be exothermic. The DWHC@PpyNC exhibited better reusability up to 4 cycles indicating its practical ability. Notably, the removal efficacy of DWHC@PpyNC for Pb2+ and Cd2+ in all the spiked samples was >78 % which also addresses its practical performance. The results obtained authenticate DWHC@Ppy as a low-cost sustainable adsorbent for mitigating heavy metals from the aquatic phase.

Keywords

• Dewax
• Polypyrrole
• Adsorption
• Isotherm
• Kinetics
• Reusability