Modification of high‑sulfur polymer using a mixture porogen and its application as advanced adsorbents for Au(III) from wastewater

Abstract

Gold is a precious resource; over-exploitation has made it increasingly scarce. It is imperative to develop advanced adsorbent materials for valid recovery of Au(III) from low-concentration industrial wastewater. In this study, a new porous high‑sulfur polymer (HSP) was prepared by the inverse vulcanization method and applied for selective recovery of Au(III) from industrial effluent. In order to study the absorptive mechanism of gold by HSP, XRD, FTIR, SEM, TG, and XPS were employed for characterization. And the effects of gold ion concentration, adsorbent dose, time, temperature, and initial pH on the adsorption performance were investigated. The results showed that the saturation absorptive capacity of gold reaches 20.98 mg/g at an optimal pH of 1.0 at room temperature. The kinetic adsorption and isotherm adsorption models considered that adsorption conforms to the pseudo-second order model and Langmuir model. Combined with XPS analysis, coordination effect was the main adsorptive mechanism of Au(III) on HSP, and the role of sulfur-containing functional groups is very significant. In addition, Au(III) in wastewater can be selectively adsorbed by HSP. Adsorption and desorption experiments indicated that HSP can be recycled at least three times. Therefore, HSP demonstrates prospects for the good practical applications in the future.