Adsorption of Pb2+ and Ni2+ Ions by Montmorillonite: Isotherm, Kinetic and Thermodynamic Studies

作者：Miao, Deren; Liu, Fei^*; Liu, Yulong; Chen, Honghan

来源：Adsorption Science and Technology, 2009, 27(8): 785-795.

DOI：10.1260/0263-6174.27.8.785

• AQUEOUS-SOLUTIONS
• ACTIVATED CARBON
• ALGINATE BEADS
• HEAVY-METAL
• CA-ALGINATE
• SORPTION
• REMOVAL
• CADMIUM
• BIOSORPTION
• NICKEL(II)

The adsorption of Pb2+ and Ni2+ ions from aqueous solution onto montmorillonite (MMT) has been investigated at 293 K, 303 K, 313 K and 323 K using batch equilibrium experiments. In order to optimize the adsorption conditions, the effects of contact time, solution pH and initial metal ion concentrations were tested thoroughly. The adsorption isotherms were best described by the Langmuir model at lower temperatures, while the Freundlich model gave a better fit at higher temperatures. The theoretical saturated adsorption capacities of MMT for Pb2+ and Ni2+ ions at 293 K as calculated via the Langmuir isotherm were 133 g/kg and 56 g/kg, respectively. The kinetic data were poorly correlated by the pseudo-first-order model and the intraparticle diffusion equation, but were fitted perfectly by the pseudo-second-order kinetic model. For Pb2+ ions, the thermodynamic parameters Delta(ads)G(0), Delta H-ads(0) and Delta S-ads(0) were determined as -3.08 kJ/mol (at 293 K), 4.83 kJ/mol and 26.95 J/(mol K), respectively. For Ni2+ ions, the values of Delta(ads)G(0), Delta H-ads(0) and Delta S-ads(0) were -1.10 kJ/mol (at 293 K), 23.77 kJ/mol and 84.63 J/(mol K), respectively. The experimental results indicated that the adsorption processes for both Pb2+ and Ni2+ ions onto MMT were favourable, spontaneous and endothermic.

• 出版日期2009
• 单位中国地质大学（北京）