RESUMEN
This study introduces a cost-effective approach to fabricating a porous and ionically surface-modified biochar-based alginate polymer networks composite (SBPC) through air drying. The study critically analyzes the role and concentrations of various components in the success of SBPC. Characterization techniques were employed to evaluate the microstructure and adsorption mechanism, confirming the ability of the adsorbent's carboxyl and hydroxyl groups to eliminate various heavy metal ions in water simultaneously. The SBPC demonstrated high copper binding capacities (937.4 mg/g and 823.2 mg/g) through response surface methodology (RSM) and column studies. It was also influential in single and natural systems, exhibiting competitive behavior and efficient removal of Cu2+. The Langmuir isotherm and pseudo-second-order kinetics strongly correlate with experimental data, with R2 values of 0.98 and 0.99, respectively. SBPC showed remarkable stability, up to 10 desorption cycles, and achieved 98% Cu2+ adsorption efficiency and 91.0% desorption. Finally, the cost analysis showed a cost of 125.68 INR/kg or 1.51 USD/kg, which is very low compared to the literature. These results highlight the potential of SPBC and show that it provides an efficient and cost-effective solution for removing Cu2+ from a real system.
RESUMEN
This work presents a novel polymer-based adsorbent, Sodium Dodecyl Sulphate modified alginate-pectin gel beads (APS221) prepared via controlled freeze drying & air drying, for the removal of copper ions from the aqueous solution. This work also critically discusses the role played by various components and their concentrations in the success of APS221. Addition of pectin to alginate resulted into approximately 150 % increase in the metal removal performance of the adsorbent while addition of SDS into alginate-pectin complex enhanced the performance by 14 % approximately, taking the maximum adsorption capacity of final complex APS221 to 111.11 mg/g. Our characterization studies revealed that the adsorption happened predominantly by complexation and ion-exchange mechanisms, and hence despite having a higher surface area, freeze-dried variant showed lesser adsorption capacity than air-dried variant as there was a loss of ion-exchange sites resulting from breakage of crosslinking bonds due to chain elongation. The adsorption process was found to follow Langmuir isotherm and pseudo-second order kinetics with a good fit of experimental data. Further, operating parameters have been optimized via RSM to, simultaneously, maximize the utilization of the adsorbent and minimize the cost of the process. Stability studies showed that APS221 beads could be used up to eight cycles.