Pb(II) Removal from Aqueous Solution by Cucumissativus (Cucumber) Peel: Kinetic, Equilibrium & Thermodynamic Study

Cucumissativus peel (CSP), was investigated as a new adsorbent for Pb(II) removal from aqueous solution under several varying conditions such as pH, adsorbent dosage, and contact time. Maximum metal sorption was found to occur at initial pH 5.0. The adsorption capacity of CSP was found to be 28.25mg/g for initial Pb(II) concentration of 25 mg/l at 25°C. The equilibrium data best fitted to the Langmuir adsorption isotherm model. Batch adsorption models, based on the assumption of the pseudo first-order and pseudo second order mechanism were applied to examine the kinetics of the adsorption. The results showed that kinetic data were followed pseudo secondorder model than the pseudo first-order equation. With no loss in the Pb(II) ion removal efficiency, CSP could be regenerated using 1M HNO3 during repeated sorption–desorption cycles and showed recovery of 93.5% for 25mg/l of Pb(II) ion concentration. Comprehensive characterization parameters using FTIR, and SEM were recorded before and after adsorption to explore the number and position of the functional groups available for Pb(II) binding onto adsorbent and changes in surface morphology of the adsorbent.