Single and binary adsorption of dyes from aqueous solutions using functionalized microcrystalline cellulose from cotton fiber

• DOI: 10.1007/s11814-020-0621-3
• Publication Date: 2020-10-05T10:04:55Z
• Authors: Hongjuan Bai; Junhang Chen; Xiangyu Zhou; Chengzhi Hu
• Keywords: Langmuir adsorption model; Methylene blue; Crystal violet; Hydrophobic effect

Simultaneous removal of dyes in the effluents of printing and dyeing industries is challenging, and the mechanism of the co-adsorption of dyes is still unclear. In this context, a novel adsorbent based on microcrystalline cellulose from cotton fiber through a simplified chemical modification process was prepared. Methylene blue (MB) and neutral red (NR) were selected to investigate their adsorption/co-adsorption on such functionalized microcrystalline cellulose. The experimental adsorption results indicated that the adsorption quantity of both dyes was similar for the single solute. The kinetics of adsorption processes could be better described with the pseudo-second order models for both single and binary dye solutes. The results of the co-adsorption suggested that the extended Langmuir model could well predict equilibrium. The maximum adsorption capacity of MB and NR for the single systems was 115.2 and 83.2 mg/g, respectively. Moreover, an antagonistic effect could be found in the binary dye solute. The obtained results revealed that the co-adsorption of dyes might be driven by hydrogen bonding, π-π stacking interaction as well as electrostatic interaction.