Lemon peel activated carbon: A sustainable solution for lead ion removal from E-waste bioleachate

Abstract

In the investigation of sustainable materials, this study explores the viability of employing Lemon Activated Carbon (LAC) for the bio-adsorption of lead ions from e-waste bio-leachate. The novelty of this work lies in the comprehensive analyses of LAC characteristics, including particle size, surface area, zeta potential, and surface morphology. The morphology and adsorption capacity were measured using scanning electron microscope (SEM) and atomic absorption spectroscopy (AAS), confirming the efficacy of LAC in removing lead ions from the bio-leachate solutions. The surface area analysis unveiled that LAC, with a surface area of 603.7 m²/g achieved through thermal activation, exhibited competitive lead ion adsorption capacity despite its lower surface area compared to commercial-activated carbon (990 m²/g). Additionally, both LAC and CAC displayed pseudo-second-order kinetics for adsorption, with the Langmuir isotherm model fitting well (R2 = 0.9879) for LAC. The amorphous nature of LAC confirmed by X-ray diffraction (XRD) analysis and FTIR spectroscopy revealed functional surface groups, highlighting their suitability for lead ion adsorption. LAC comprised 75.82% carbon and exhibited maximum lead ion adsorption at pH 6. The optimized operating parameters achieved 89.16% lead ion removal from bio-leachate. These findings highlight the innovative utilization of lemon peel-derived activated carbon as a sustainable and environmentally friendly solution for mitigating the impacts of e-waste bio-leachate, thus contributing to the advancement of environmental remediation techniques.