Sorption of La(III) and Ce(III) by Oxidized Carbon Nanotubes

The ion-exchange sorption of La(III) and Ce(III) from nitrate solutions using oxidized carbon nanotubes with a solubility of 4.2 g/L is studied at metal concentration. = 5-160 mg/L, pH 2.5-6.0, ratio S : L = 0.002-0.06, and room temperature. At. = 35 mg/L, the equilibrium capacity is shown to grow dramatically with.. rising from 3.0 to 4.0-4.5 and reaching 840 mg/g in La and 950 mg/g in.. when S : L < 0.006 and pH > 4.0-4.5. The introduction of ionic salts is found to reduce the capacity (at pH > 4 and concentrations of 0.01. and 0.1. NaCl, the.. capacity is reduced to similar to 500 and similar to 200 mg/g). It is concluded that the sorption equilibrium is better described by the Langmuir equation, while the process kinetics, by pseudo-first and pseudo-second order equations.