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

Abstract

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.

Investigation and optimization of cadmium ion adsorption from wastewater using raw and activated carbon of Pterocarpus santalinoides fruit

“…The significant changes were seen on the surfaces of this adsorbent after adsorption of Cd 2+ ions. These results revealed that raw and activated carbon derived from the Pterocarpus santalinoides fruit has enough active surface area and binding cavities to adsorb cadmium ions [16]. The result of the mineral content of the raw and activated carbon of Pterocarpus santalinoides fruit shows that sodium recorded the highest amount in both the raw (0.2577 mg/g) and activated carbon derived from fruit (0.2819 mg/g) while magnesium recorded the least value in raw (0.1997mg/g) and activated carbon (0.1720mg/g) as tabulated in Table 1.…”

“…The adsorption percentage of Cd 2+ decreased from 99.79 to 80.57% and 99.40 to 81.76% for raw and activated carbon of Pterocarpus santalinoides fruit respectively. This trend is possible because the number of available adsorbent active sites is more when compared to the number of cadmium ion at lower concentration [16]. This result indicates that low adsorption percentage was recorded at high initial cadmium concentrations.…”

“…The adsorption rate was observed to decrease with increasing temperature. This phenomenon shows that the adsorption process is exothermic and no strong chemical bond was formed during adsorption [16].…”