Selective Adsorption of Ag⁺ on a New Cyanuric-Thiosemicarbazide Chelating Resin with High Capacity from Acid Solutions.

Guo Lin,Song Cheng,Shixing Wang,Tu Hu,Libo Zhang,Jinhui Peng,Likang Fu

doi:10.3390/polym9110568

Abstract

A new cyanuric-thiosemicarbazid (TSC-CC) chelating resin was synthesized and employed to selectively adsorb Ag+ from acid solutions. The effects of acid concentration, initial concentration of Ag+, contact time and coexisting ions were investigated. The optimal acid concentration was 0.5 mol/L. The adsorption capacity of Ag+ reached 872.63 mg/g at acid concentration of 0.5 mol/L. The adsorption isotherm was fitted well with the Langmuir isotherm model and the kinetic data preferably followed the pseudo-second order model. The chelating resin showed a good selectivity for the Ag+ adsorption from acid solutions. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy/energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) were used to study the adsorption mechanism. The chelating and ionic interaction was mainly adsorption mechanism. The adsorbent presents a great potential in selective recovery Ag+ from acid solutions due to the advantage of high adsorption capacity and adapting strongly acidic condition. The recyclability indicated that the (TSC-CC) resin had a good stability and can be recycled as a promising agent for removal of Ag+.

Highlights

The wastewater containing Ag, Hg, Pb, Co, Cd, Ni, and Cu has been more and more noticed because of the potential hazards to human, animals, and the environment [1]
The results indicated that the chelating resin had been successfully synthesized
The results indicated that the TSC-CC resin was a promising material for selective adsorption of Ag+ from the acid solutions with the coexisting ions

Summary

Introduction

The wastewater containing Ag, Hg, Pb, Co, Cd, Ni, and Cu has been more and more noticed because of the potential hazards to human, animals, and the environment [1]. Within these metals, silver is a typical toxic heavy metal coming from coinage, metallurgy, electronics industries, and photography [2,3,4]. The traditional methods for recovery Ag+ from wastewater include precipitation, electrolysis, ion exchange, membrane separation, and adsorption [3]. Adsorption is an emerging technique due to easy operation, low energy consumption and high-efficiency [6]

Methods

Results

Conclusion