Activated carbon derived from silk sericin for efficient adsorption of methylene blue in aqueous solutions

The silk sericin (SS) recovered from silk degumming wastewater can be used to develop carbonaceous materials for organic dye removal from wastewater. To improve the adsorption capacity of the carbonaceous adsorbents derived from SS, KOH was used as an activation agent. The maximum adsorption capacity of SS-based activated carbon on methylene blue (MB) was determined by batch adsorption experiments as 964.63 mg/g. Mathematical models of adsorption were studied to reveal the adsorption mechanism. According to adsorption kinetics analysis, a pseudo-second-order model describes the adsorption performance of SS-based activated carbon on MB more appropriately, and the adsorption process follows the Langmuir model. The activated carbon prepared from SS in this work demonstrated improved MB adsorption capacity compared with other SS-based carbonaceous materials and therefore presented prosperous application possibilities for removing organic dyes from wastewater.

Creation and application of silk sericin-derived activated carbon. The silk sericin was first enriched from the silk degumming wastewater, then was converted into activated carbon by heating and activation. The generated activated carbon was later used for the adsorption of methylene blue from aqueous solutions through electrostatic and π-π interactions