Removal of lead ions from wastewater using raw and activated carbon of Pterocarpus santalinoides shell

Removing toxic metals from the environment is a primary concern for researchers because of their hazardous effects. In this study, raw and activated Pterocarpus santalinoides shell was utilized in removal of lead (Pb) metal from an aqueous solution. The prepared adsorbents were analysed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and mineral composition to identify their structural composition and understand the adsorption mechanism. The influence of various adsorption variables such as dose of adsorbents, initial concentration of lead metal, contact time, solution temperature, and adsorption isotherms, kinetics, and thermodynamic parameters was studied. Adsorption efficiencies and capacities for the adsorbents were calculated. Based on the results generated, the two different adsorbents utilised showed a good alternative to commercial materials, with removal efficiencies greater than 80%. The Langmuir isotherm and pseudo-second-order model showed good fits to the experimental data. Moreover, the thermodynamic results revealed that the adsorption of Pb ions via the raw and activated carbon of Pterocarpus santalinoides shell was an endothermic and spontaneous process. According to this research, Pterocarpus santalinoides shell, being an agricultural waste, might be explored as an efficient adsorbent for extracting Pb ions from wastewater.