Sorption of Ni(II) by sol-gel silica functionalized with DMG and other chelating agents

Abstract

In this study, a comprehensive investigation of doping of sol-gel silica with DMG and other chelating agents is provided at room temperature using infrared spectroscopy, elemental analysis, SEM, EDS and powder XRD. Sol-gel silica was doped with dimethyl glyoxime (DMG), ethylenediamine (EDA), 1,10-Phenanthroline (Phen), dithizone (DZ), and sulfanilamide (SB) to investigate the sorption of Ni(II) from aqueous media. It is observed that the chelating agents are encapsulated by the pores of the xerogel from where they interact with the metal ions by ion exchange and chelation mechanism. Nickel complexes of the chelating agents were also synthesized. Sol-gel silica was doped with metal complexes for comparison with sol-gel silica with sorbed metal ions. Ni(II) in metal complex was compared with that in functionalized silica from EDS of both samples. The batch adsorption experiments were performed at room temperature and neutral pH. The developed method can be applied on large scale removal of Ni(II) using silica and chelating agents from cheap natural sources. The sorption process was completed within 5 minutes and 0.1 N HNO₃ resulted in complete desorption of metal ions. The regenerated sorbent can be reused six times with negligible loss of sorption capacity.

Graphical Abstract

HIGHLIGHTS

• Sol-gel silica was functionalized with DMG and other chelating agents for the removal of Ni(II) from aqueous media.

• Sol-gel silica was also functionalized using Ni complexes of the chelating agents for comparison.

• DMG functionalized sol-gel silica showed high sorption capacity and fast desorption of Ni(II) at room temperature and neutral pH.

• The sorption process was completed in 5 minutes. 0.1 N HNO₃ resulted in complete desorption of metal ions. The regenerated sorbent can be reused six times with negligible loss of sorption capacity.

• The developed method can be applied on large scale removal of Ni(II) if we use silica and chelating agents obtained from cheap natural sources.

Keywords:

• Chelating agents
• metal complexes
• sorption
• nickel
• DMG functionalized sol-gel

Acknowledgements

The authors are thankful to Advanced Engineering Research Organization, Hasan Abdal, Wah Cantt, Pakistan, for helping in analysis and characterization of the sorbent materials.

Authors’ contributions

All authors have significant contribution.

Consent to participate

Agreed.

Consent for publication

Agreed for publication.

Disclosure statement

We do not have any conflicts of interest to declare.

Data availability statement

The data required to reproduce the above findings cannot be shared at this time due to technical/time limitations.

Ethics approval

The accepted principles of ethical conduct have been followed.