Thermodynamics and kinetics of biosorption of aqueous Co(II) ions on pectin bead-based Teabag

Contamination of water through heavy metal ions has received great attention and wide-ranging consequences for human health and living beings. Polymer@metal oxide composites are good candidates for detoxification of water contaminants. Herein, we report pectin@Fe3O4-La2O3 (PFLO) beads for the selective adsorption of aqueous Co(II) ions. The synthesized PFLO beads are eco-friendly, low-cost, easy to handle, simple, and have good adsorption selectivity. The Co(II) adsorption was well fitted by Langmuir and Pseudo-second-order kinetic models. Response surface modeling (RSM) was used to examine the adsorption process of PFLO beads for Co(II) adsorption. Different characterization techniques were used to explain the fabrication and adsorption mechanism i.e., XPS, XRD, FTIR, BET, FESEM, EDAX, and TGA. The monolayer adsorption capacity of synthesized PFLO beads at 318 K was found to be 344.82 mg/g. The thermodynamic studies demonstrate the adsorption process is spontaneous, workable, and endothermic. Teabag's experiment shows the commercial application of the adsorbent. The PFLO beads nanocomposite maintains 74% reusability for Co(II) adsorption even after five cycles. The developed PFLO nanocomposites can be used as potential adsorbents for effective, reproducible and selective adsorption of aqueous Co(II). This paper will be beneficial for researchers working towards further improving water purification technologies.

Automated summary

In this paper, pectin@Fe3O4-La2O3 (PFLO) beads were synthesized for the selective adsorption of Co(II) ions in water. The PFLO beads demonstrated eco-friendly, low-cost, easy to handle, and good adsorption selectivity. Characterization techniques were used to explain the fabrication and adsorption mechanism, and the adsorption capacity of PFLO beads was found to be 344.82 mg/g at 318 K. The developed PFLO nanocomposites show potential for effective and selective adsorption of Co(II) in water.