REMOVAL OF HEAVY METALS FROM INDUSTRIAL WASTEWATER USING EGG-SHELL ACTIVATED CARBON

Abstract

This study explores the preparation and application of eggshell activated carbon (ESAC) as an efficient adsorbent for the removal of heavy metals, specifically
lead (Pb) and nickel (Ni), from industrial wastewater. The study involved characterization of ESAC to determine its physical and chemical properties, followed by
adsorption experiments to assess its efficiency in heavy metal removal. ESAC was synthesized from waste eggshells and thoroughly characterized using BET
surface area analysis, SEM, XRD, and FTIR to confirm its adsorption properties. Experimental adsorption tests showed that ESAC achieved removal efficiencies
of 80% for lead and 65% for nickel under optimized conditions including pH, adsorbent dosage, contact time, and initial metal concentration. Adsorption isotherm
analysis revealed that the Freundlich model best described the adsorption process, with Freundlich constants KF of 0.25 mg/g for Pb and 0.21 mg/g for Ni,
indicating favourable adsorption. The Langmuir maximum adsorption capacities (qmax) were 45.7 mg/g for Pb and 41.2 mg/g for Ni. A comparative cost-benefit
analysis highlighted the economic advantages of using ESAC over conventional activated carbon, that is, ESAC production costs were significantly lower compared
to commercial activated carbon, highlighting its economic viability. This study confirms the potential of eggshell-derived activated carbon as an eco-friendly and
economical solution.