Application of Activated Eggshell as Effective Adsorbent in the Removal of Lead (II) Ion from Fertilizer Plant Effluent

Abstract

The adsorption of lead (II) ions from fertilizer wastewater using Acid Modified Eggshell (AMES) as adsorbents was studied. The effects of process parameters such as temperature, contact time, pH and adsorbent dosage on the adsorption of Lead (II) ions from fertilizer industrial waste water were investigated. FTIR spectrum was employed to investigate the functional groups present in the egg shell before and after modification. Scanning Electron Microscope (SEM) was used to study the surface morphology of the egg shell before and after modification. Kinetic and isotherm model of the best fit for the data was investigated using the established models. FTIR characterization revealed that some functional groups disappeared while new ones appeared after modification indicating effective modification. SEM analysis revealed that the microporous spaced increased after modification. The process factors considered significantly affected the rate of lead ion adsorption. Batch adsorption studies demonstrated that the highest percentage of 94.6% of lead ion was removed at a dosage of 40 mg of adsorbent per 100 ml of effluent after 60mins at a pH of 5 with optimum temperature of 45°C. The adsorption isotherm suggested a good fit of the experimental data into Temkin models with 0.998 as the R2 value. Second order kinetic model was found to be the best fit for the adsorption data. Thermodynamic studies revealed that the adsorption of lead ion onto activated egg shell is endothermic with entropy and enthalpy value as 0.025 kJ/mol.k and 15.96 kJ/mol, respectively. Results obtained showed that acid modified egg shell is a good adsorbent for the removal of lead ion from wastewater.