Rational fabrication of completely amorphous chitosan-formyl-sucrose sorbents with excellent durability and regenerability for high-throughput dye removal

Abstract

We have developed chitosan-formyl-sucrose sorbents with densely charged groups and ultra-low polymer chain density via a room-temperature one-step approach for industrial adaptations. This sorbent reaches theoretic sorption and maximum desorption capacities with extremely high concentration factors suitable for fast continuous dye removal. We focus on the development of affordable cleaning technology. Such a technology must have high cleaning capacity and durable reusability. Via sorption of three reactive dyes, Reactive Blue 19, Reactive Black 5, and Reactive Red 120, the sorbent we report provided a dyestuff sorption capacity of as high as 7 g/g, 99% of its theoretical sorption value, due to its densely charged groups and complete accessibility. This sorbent also exhibited a 99% desorption efficiency even when the eluate concentrated 19 times the initial dye solution due to the adjustable charged groups and ultra-low polymer chain density, therefore, minimal van der Waals attractions to the dyes. Formyl-sucrose endows the sorbents with desirable mechanical properties and excellent water stability for high-speed continuous wastewater cleaning and sorbent regeneration readily adaptable to cost-effective industrializations.