A acylthiourea based ion-imprinted membrane for selective removal of Ag+ from aqueous solution

Abstract

The efficient removal of Ag+ ions from wastewater not only preserves the environment but also promotes the reutilization of silver metal. Therefore, in this study, we have developed an advanced ion imprinted membrane (IIM) and employed it as an adsorbent for the efficient removal of Ag+ ions from aqueous solution. The dynamic adsorption results demonstrated that the prepared IIM exhibited superior filtration and separation performance when applied to feed solutions with lower concentrations (12 mg/L) and higher pH levels (pH=6). The presence of co-existing metal ions in the feed solution had negligible impact on the separation efficiency of IIM towards Ag+ ions, highlighting its exceptional recognition ability and selective separation capability. The results from static adsorption experiments indicated that the adsorption of Ag+ ions onto the membrane surface conformed to both Langmuir model and the pseudo-second-order model, indicating that the adsorption process was a monolayer chemisorption. Reusability findings revealed a slight decline in uptake capacity and water flux of IIM after five desorption-adsorption cycles, showcasing its potential application value in Ag+ ions removal. The EDS, FTIR and XPS results substantiated that Ag+ ions were adsorbed onto the IIM surface through the chemical reactions between Ag+ ions and CS and CO groups.