Fabrication of cationic cellulose nanofibrils/sodium alginate beads for Congo red removal

Meiyan Wu; Yidong Zhang; Xiaoyan Feng; Fei Yan; Qian Li; Qiu Cui; Bin Li

doi:10.1016/j.isci.2023.107783

Fabrication of cationic cellulose nanofibrils/sodium alginate beads for Congo red removal

iScience. 2023 Aug 29;26(10):107783. doi: 10.1016/j.isci.2023.107783. eCollection 2023 Oct 20.

Authors

Meiyan Wu¹, Yidong Zhang^{1

2}, Xiaoyan Feng¹, Fei Yan¹, Qian Li³, Qiu Cui^{1

4

5}, Bin Li^{1

4

5}

Affiliations

¹ CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P.R. China.
² Laboratory of Natural Materials Technology, Åbo Akademi University, 20500 Turku, Finland.
³ Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, P.R. China.
⁴ Shandong Energy Institute, Qingdao 266101, P.R. China.
⁵ Qingdao New Energy Shandong Laboratory, Qingdao 266101, P.R. China.

Abstract

Congo red is hard to remove from dye wastewater due to its structure stability and high chemical oxygen demand. In this study, cationic cellulose nanofibrils (CCNF) prepared from herb residues was physically crosslinked with sodium alginate (SA) in the presence of calcium ions, and the obtained CCNF/SA beads were used to adsorb Congo red. Results showed that CCNF/SA beads with porous internal structure were beneficial to adsorption. The maximum adsorption capacity of Congo red could reach to 518.4 mg/g, which was superior to most cellulose-based adsorption materials. Furthermore, the equilibrium adsorption isotherms and XPS analysis indicated the adsorption for Congo red was a physical process, and hydrogen bond and electrostatic adsorption were proposed as dominant adsorption mechanism. In addition, the Congo red removal efficiency of the beads was still higher than 70% after three cycles. Therefore, this high efficiency and green beads have great potential as adsorbents for anionic dyes removal.

Keywords: Biomaterials; Chemistry; Environmental engineering; Materials chemistry; Materials science.