Enrichment of Cu(II), Ni(II), and Pb(II) in Aqueous Solutions Using Electrospun Polysulfone Nanofibers Functionalized with 1-[Bis[3-(Dimethylamino)-propyl]amino]-2-propanol

Abstract

Polysulfone functionalized with 1-[bis[3-(dimethylamino)-propyl]amino]-2-propanol was electrospun into nanofibers and then employed as a novel platform for the enrichment of Cu(II), Ni(II), and Pb(II) metal ions in aqueous solutions. Parameters affecting adsorption such as fiber diameter, contact time, and pH were investigated. The capacity of the functionalized electrospun fibers to enrich metal ions from various aqueous matrices such as tap water, river water, seawater, treated as well as untreated sewage, was evaluated for spiked samples by inductively coupled plasma optical emission spectroscopy. The equilibrating times for maximum enrichment were 20 min for Cu(II) and Pb(II) respectively and 30 min for Ni(II). Recoveries, in 100 mg L⁻¹ metal ion solutions, ranged from 89.58% (in untreated sewage) to 99.86% for Cu(II) in tap water, 69.70% (in untreated sewage) to 98.64% (in river water) for Ni(II), and from 71.46% (in untreated sewage) to 99.01% (for seawater) for Pb(II). The lowest concentration of metal ions that the functionalized nanofibers could detect in real sample matrices was 0.001 mg L⁻¹. The metal adsorption kinetics followed a first order rate while the adsorption isotherms best fitted into the Freundlich model. The nanofibers could be regenerated and reused up to five times without a significant deterioration in adsorption and desorption efficiencies. The functionalized electrospun nanofibers present an excellent platform for trace enrichment of metal ions from aqueous solutions at pH values close to that at which the pollutants occur in the environment.

Keywords:

• Adsorption
• Electrospinning
• Enrichment
• Nanofiber
• Polysulfone

Acknowledgments

This paper is part of a Special Issue of Analytical Letters focusing on papers presented at the 10th International Symposium on Kinetics in Analytical Chemistry (KAC-10).

The authors gratefully acknowledge the financial support from the African Network of Analytical Chemists (SEANAC).

Notes

Mean recovery (%), relative standard deviation (% RSD), limits of detection (LD) for adsorption of metals in 100 mg L⁻¹ solutions prepared with natural waters (n = 3). Background is the concentrations of metal ions originally present in the natural water samples.