Removal of Ni(II) Using Multi-walled Carbon Nanotubes Electrodes: Relation Between Operating Parameters and Capacitive Deionization Performance.

Experiments were conducted to develop a statistical model which describes the relation between operating parameters and capacitive deionization performance for the removal of Ni(II) ion using multi-walled carbon nanotubes (MCNT) electrodes. The $$R^{2}$$ value of 0.84 in regression analysis represents that the statistical model reproduced the data well. The factors for pH ( $$a = 0.242$$ ), applied voltage ( $$b = 0.619$$ ) and retention time ( $$c = 0.504$$ ) in the statistical model revealed the significance of each parameter. The effect of initial Ni(II) concentration is best described by Langmuir isotherm. Kinetic study showed that pseudo-first-order equation fitted the data well. Modeling the performance with operating parameters for the removal of Ni(II) using MCNT electrodes is feasible, and results can be used for practical engineering applications. [ABSTRACT FROM AUTHOR]