Citric acid functionalized cellulose monolith for continuous‐flow removal of cationic dye in water

Abstract

Developing efficient yet cost‐effective material from bioresources for dye removal is promising in both economic and environmental protection aspects. Here, a monolithic cellulose material functionalized with citric acid is reported as an absorbent for continuous‐flow removal of cationic dye. The functionalization process is realized by a direct esterification reaction between citric acid and cellulose without any other additions. The obtained monolithic absorbent possesses a 3D connected porous structure, which enables the application of the product in a continuous‐flow fashion. Results indicate that the produced monolith has a good adsorption ability to methylene blue. Moreover, the product can be reused after a fast desorption process by flowing with a salt solution. This work provides a simple strategy for fabricating green absorbents based on biofriendly cellulose and citric acid, which exhibits a potential of industrial application for water treatment.