Adsorption of Pb(II) on modified ground nut shell (MGNS): Isotherm, kinetic, and thermodynamic study

Abstract

The environmental impact of lead compounds is significant. Lead compounds are typically consumed through drinking water and offer a substantial danger. Pb(II) and related compounds are hazardous and have been classified as probable human carcinogens by distinct regulatory authorities. For a regulatory and health standpoint, Pb(II) ion removal from waste water and water is crucial. By sulfuric acid activation, groundnut shell (GNS) has been converted into low-cost activated carbon and grafted with EDTA to make modified groundnut shell (MGNS) powder. An analysis has been conducted on its capacity to adsorb Pb(II) ions from aquatic solutions. An MGNS sample has been examined using SEM, BET, and FTIR techniques, revealing the presence of a porous framework with a surface area of 2143 m2/g. The absorption system adhered to a pseudo-second-order kinetic model, with the equilibrium time being determined at 120 minutes. The adsorption isotherms have been accurately simulated by the Langmuir model. A mechanism involving ion exchange has been suggested by the substantial pH dependence of Pb(II) adsorption on MGNS. Studies on regeneration have shown that MGNS can be reused repeatedly by desorbing them with HCl.