Fabricating Cationic Lignin Hydrogels for Dye Adsorption

Chao Wang, Xuezhen Feng, Wanbing Li, Shibin Shang^*, Haibo Zhang^*
Institute of Chemical Industry of Forest Products, CAF; National Engineering Laboratory for Biomass Chemical Utilization; Key Laboratory of Chemical Engineering of Forest Products, National Forestry and Grassland Administration; Key Laboratory of Biomass Energy and Material, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing, 210042, China
* Corresponding Authors: Shibin Shang. Email: shangsb@163.com; Haibo Zhang. Email: shdzhanghaibo@163.com
(This article belongs to this Special Issue: Lignocellulosic Bionanomaterials)

Journal of Renewable Materials https://doi.org/10.32604/jrm.2023.024521

Received 01 June 2022; Accepted 03 August 2022; Published online 22 September 2022

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Abstract

Due to the low content of adsorption-active groups in lignin, its application in the field of adsorption is limited. Herein, we first prepared cationic kraft lignin acrylate, from which a cationic lignin (CKLA) hydrogel was further prepared by cationic kraft lignin acrylate, acrylamide, and N, N’-methylenebisacrylamide. The morphology, compression properties and swelling properties of CKLA hydrogels were investigated. The prepared CKLA hydrogel was applied as an adsorbent for Congo red. The effect of CKLA hydrogel dosages, initial concentration of Congo red, and pH on adsorption efficiency was investigated. The maximum Congo red removal efficiency was obtained at the initial concentration of Congo red of 50 mg/L, pH 7, and 5 mg dosage of CKLA hydrogel with 20% cationic lignin content. After five cycles of adsorption, the adsorption efficiency of the hydrogel for Congo red still reached more than 80%. The CKLA hydrogel showed pseudo-second-order adsorption kinetics for Congo red adsorption. These results demonstrate the potential of the CKLA hydrogel as an adsorbent for water treatment.