摘要：Ethylenediaminetetraacetic dianhydride modified coconut frond (ECFP) was prepared, characterized and applied as a potential adsorbent to remove Pb(II) ions from aqueous solutions. Factors influencing adsorption such as pH of the solution, adsorbent dosage, Pb(II) concentration, contact time, and temperature were investigated. The optimum conditions for adsorption of Pb(II) ions were at pH 4 and dosage of 0.02 g. Adsorption reached its equilibrium state in 30 min for all Pb(II) concentrations. Chemisorption was suggested as the rate-limiting step as the adsorption process correlated well with the pseudo-second-order kinetics model. Based on adsorption isotherm results, Langmuir model fitted the experimental data well, and the maximum adsorption capacity was 84.03 mg.g-1 at 300 K. Based on the thermodynamic study, Pb(II) adsorption occurred spontaneously with the enthalpy and entropy changes recorded were 0.0615 kJ mol-1 and 241.28 J K-1 mol-1, respectively. It was found that the nature of adsorption was endothermic as the ∆Ho value obtained was positive.
