Adsorption of Ag (I) from Aqueous Solutions Using Regenerated Silk Fibroin Adsorbent Beads

Abstract

In this work, a novel and eco-friendly biosorbent, regenerated silk fibroin bead (rSFB) was successfully produced and used as a low-cost adsorbent to remove silver ion from wastewater. Batch adsorption experiments demonstrated that rSFB could effectively remove silver ion in particular. Factors influencing the adsorption of silver ion, e.g. contact time, solution pH, and adsorbent dosage were systematically investigated. Isotherm equilibrium studies demonstrated that the silver ion adsorption process followed the Langmuir model. The maximum adsorption capacity for silver ion was estimated to be 62.50 mg/g and the removal efficiency could reach up to 98.82%. The kinetics study showed that the adsorption process followed the second-order kinetic model. The adsorbent was stable and active for up to four successive cycles. The batch experimental results suggested that rSFB could be used as an efficient adsorbent to remove silver from wastewater.

Keywords

• adsorption
• silk fibroin
• bead
• silver
• biosorbent