Dye anionic sorption in aqueous solution onto a cellulose surface chemically modified with aminoethanethiol

The natural biopolymer cellulose was initially chlorinated at the 6 carbon with a degree of substitution (DS) 0.99 ± 0.01 and then reacted with aminoethanethiol to form a modified compound with different basic centers, and this material was characterized by elemental analysis, XRD, TG, FTIR and 13C NMR. The matrix obtained was effective in removing red reactive anionic dye in an aqueous medium at pH values of 2 and 9. The equilibrium time of adsorption obtained was approximately 100 min (pH 2) and 160 min (pH 9), and the kinetics for both systems followed a pseudo-second-order model. The adsorption isotherms at different pH levels at three different temperatures obeyed the Langmuir model, and the maximum adsorption capacities were 78 mg g−1 (pH 2) and 26 mg g−1 (pH 9), and the interaction was electrostatic and hydrogen bonds and/or covalent, respectively.

• Cellulose was modified with aminoethanethiol.
• The kinetic sorption occurs in pseudo-second-order model.
• The excellent pH’s for interaction was 2 and 9.
• The experimental data was adjusted to Langmuir model.
• New material could be employed as low-cost material for the removal of anionic dye.