Biobased hydrogel reinforced with wastepaper-derived modified cellulose nanofiber as an efficient dye remover from wastewater

In this work, starch, itaconic acid, and acrylic acid-based hydrogel was prepared with incorporation of wastepaper derived modified cellulose nanofiber (mCNF) and used as an efficient adsorbent for the removal of cationic dye such as methylene blue (MB), methyl violet (MV), malachite green (MG) and cresol red (CR) from their aqueous media. Moreover, the structure and stability of mCNFs were analyzed using various analytical techniques, while reinforced hydrogel nanocomposite was characterized by different spectroscopic and microscopic techniques. The water swelling study showed that the prepared hydrogel nanocomposite possessed maximum water absorption capacity of 754 g/g due to the incorporation of mCNF within the hydrogel matrix. Besides, mCNF embedded hydrogel possessed a maximum dye adsorption capacity of 414, 405, 377 and 323 mg/g for MB, MG, MV and CR, respectively. The adsorption kinetic and isotherms were found to be fitted well with pseudo-second-order kinetics and Freundlich isotherm model, respectively. Further, reusability test and adsorption of dyes from mixed dye-solution were carried out indicating the prepared hydrogel could effectively remove cationic dyes from the mixture and possessed excellent recyclable properties up to three repeated cycles. Thus, the present study highlights the application of the prepared hydrogel as an effective adsorbent for the removal of cationic dyes from the aqueous media.