J. Mater. Sci. Technol. ›› 2023, Vol. 159: 81-90.DOI: 10.1016/j.jmst.2023.02.045

• Research Article • Previous Articles     Next Articles

Smart superabsorbent alginate/carboxymethyl chitosan composite hydrogel beads as efficient biosorbents for methylene blue dye removal

Zhen Zhanga,b,*, Noureddine Abidib,**, Lucian Luciaa,c,*   

  1. aDepartment of Forest Biomaterials, NC State University, Raleigh, NC, USA;
    bFiber and Biopolymer Research Institute, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, USA;
    cDepartment of Chemistry, NC State University, Raleigh, NC, USA
  • Received:2022-12-16 Revised:2023-02-13 Accepted:2023-02-27 Published:2023-10-01 Online:2023-04-07
  • Contact: *Department of Forest Biomaterials, NC State Univer- sity, Raleigh, NC, USA. **E-mail addresses: . zha03518@ttu.edu , zhangz@unm.edu (Z. Zhang), Noureddine.Abidi@ttu.edu (N. Abidi), lalucia@ncsu.edu (L. Lucia)

Abstract: The presence of toxic dyes in the aqueous medium has threatened environmental safety, and thereby removing them from wastewater in an efficient way is highly desired. Herein, the efficient biosorbents were successfully fabricated via a facile physical gelation process of sodium alginate (SA) and carboxymethyl chitosan (CMCTS) in an acidic aqueous solution. The as-prepared hydrogel beads not only displayed water superabsorbent properties and pH-responsive swelling characters but also exhibited excellent methylene blue (MB) adsorption capacity removal efficiency with experimental maximum MB adsorption capacity of 2518 and 1005 mg g-1, which are comparable with most reported lignocellulosic and alginate-based hydrogels. The MB adsorption process fitted well in different kinetic and isotherm models and became more heterogeneous in concentrated MB solutions as verified by principal component analysis results. The adsorption mechanism was proposed, and the high dye absorbency was attributed to the strong electrostatic forces between adsorbents and adsorbates. Our current study provides a promising and sustainable composite hydrogels platform targeted to dye decontamination.

Key words: Hydrogel, Dye adsorption, Composites, Superabsorbent, Sodium alginate, Carboxymethyl chitosan