Effect of Ca(II), Fe(II), and Fe(III) on Cu(II) adsorption by a polyvinylidene fluoride-based chelating membrane from Cu(II)–EDTA complex solution

ABSTRACT

A polyvinylidene fluoride-based membrane bearing the diethylenetriaminepentaacetic acid chelating group was employed to recover Cu(II) from the Cu(II)-ethylenediaminetetraacetic acid complex aqueous solution. Effects of Ca(II), Fe(II), and Fe(III) on Cu(II) uptake were investigated by static batch adsorption tests and dynamic adsorption filtration. Isotherms, kinetics, and breakthrough curves of Cu(II) uptakes in the presence of the three cations at concentrations of 1 mmol L⁻¹ were elucidated. The three cations showed a positive effect on the Cu(II) uptake; the stimulative roles were in the order of Fe(III) > Fe(II) > Ca(II). They did not alter the adsorption behavior of the membrane; adsorption isotherms and kinetics could be described by Langmuir and Lagergren second-order models, and Cu(II) adsorption was a spontaneous and exothermic process. The presence of Ca(II), Fe(II), and Fe(III) increased the sorption capacity of the membrane stack by 1.3, 1.9, and 3 times. Breakthrough time and the exhaustion time of membrane stacks were also extended.

KEYWORDS:

• Polyvinylidene fluoride-based chelating membrane
• diethylenetriaminepentaacetic acid group
• adsorption
• Cu(II)–EDTA complex
• coexisting cation

Acknowledgments

Herein, we are very grateful to the editors and the reviewers for giving the valuable and instructive comments.

Disclosure statement

For all authors, there is no any actual or potential conflict of interest including financial, personal or other relationships with other people or organizations.

Additional information

Funding

This work was supported by the Scientific Research Foundation of the Hebei Higher Education Institutions of China [grant number ZD2015120].