ABSTRACT
The purpose of this research was to synthesise the chitosan-polyacrylamide composite (CH-PAA) and follow up with an investigation of its capacity to adsorb anionic Sirius yellow K-CF dye, under different environmental conditions. In order to increase the uptake value of the synthesised CH-PAA, the surface chemistry of this adsorbent was modified by bringing it into contact with ZnO nanoparticles (CH-PAA-ZnO). The characterisation tests using XRD, FT-IR, TEM, and FE-SEM analyses demonstrated the successful loading of ZnO onto the CH-PAA surface without causing damage to the chemical composition of the original materials. Excellent removal efficiency of the Sirius yellow K-CF dye (≈ 100%) by CH-PAA-ZnO was performed under the conditions cited namely, pH of 2, dye concentration of20 mg/L, adsorbent dosage of 0.05 g/L, temperature of 40°C, and contact time of 90 minutes. It was evident that the ZnO nanoparticles strongly facilitate the removal process, in which 42% enhancement of dye removal efficiency was recorded, after the CH-PAA was modified with these nanoparticles. The values of the thermodynamic parameters determined at different concentrations of Sirius yellow K-CF dye (negative values; and positive
and
values) indicated that the dye adsorption process onto the CH-PAA-ZnO was favourable, spontaneous, and endothermic. Based on the R2 values (> 0.99) of the linear fitting determined, the experimental data pertinent to the isotherm and kinetic studies are represented by the Langmuir isotherm and pseudo-second-order kinetic formulas, respectively. Also, the isotherm study revealed that 1 g of CH-PAA-ZnO was capable of capturing 149.79 mg of the dye molecules in 1 L aqueous solution. On comparison with the other adsorbent used for the same purpose, the CH-PAA-ZnO can be an efficacious adsorbent and a good alternative to treat wastewater containing Sirius yellow K-CF dye, in an acidic medium.
Acknowledgments
The authors express their gratitude to the Payame Noor University of Tehran (Iran) and Birjand University of Medical Sciences (Iran) for providing the financial and laboratory assistance in conducting this research. Also, the special thank to Al-Mustaqbal University College (Babylon, Iraq) for providing support to conduct the this study.
Authors contributions
Narjes Sadat Mazari Moghaddam: Writing and discussion. Tariq J. Al-Musawi: Writing, software, and editing. Fatemeh Sadat Arghavan: Writing and data analysis. Negin Nasseh: Editing, discussion, and supervision.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
All data generated or analyzed during this study are included in this published article.