Application of Isotherm and Kinetic Models for the Removal of Lead Ions from Aqueous Solutions

作者：Ibrahim Hanan S; El Kady Ahmed A; Ammar Nabila S; Meesuk Ladda; Wathanakul Pornsawat; Abdel Wahhab Mosaad A^*

来源：Journal of Environmental Engineering, 2013, 139(3): 349-357.

DOI：10.1061/(ASCE)EE.1943-7870.0000646

• Lead
• Bentonite
• Thailand natural clays
• Kinetics model
• Isotherm model

The aims of the current study were to evaluate the ability of three types of Thai bentonite (TNBC) for the removal of lead ions [Pb(II)] from aqueous solutions. Batch-adsorption kinetic experiments revealed that the sorption of Pb(II) onto TNBCs was very fast and reached equilibrium after 30 min. The adsorption mechanisms in the Pb(II)/TNBC system follow pseudo-second order reactions. The adsorption isotherm of Pb(II) follows both Langmuir and Freundlich models. The maximum adsorption capacities for the three tested clays were 45.46, 40.00, and 47.62 mg/g, respectively. The results also revealed that the sorption energy (E-value) were 15.18, 11.85, and 17.25 kJ/mol, respectively, for the three tested clays. Desorption of Pb(II) ions and regeneration of the natural clays were attained simultaneously by acid elution. Even after four cycles of adsorption-elution, the adsorption capacity was maintained, and the decline in efficiency was less than 10%. It is concluded that Thai bentonite has an affinity to lead ions from aqueous solutions and might have a potential to be used effectively to remove Pb(II) wastewater. DOI: 10.1061/(ASCE)EE.1943-7870.0000646.

• 出版日期2013-3