Development of a chitosan/nanosilica biocomposite with arene functionalization via hydrothermal synthesis for acid red 88 dye removal

• Published in: International Journal of Biological Macromolecules
• Main Author: Wu R.; Abdulhameed A.S.; Jawad A.H.; Yong S.K.; Li H.; ALOthman Z.A.; Wilson L.D.; Algburi S.
• Format: Article
• Language: English
• Published: Elsevier B.V. 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85168810330&doi=10.1016%2fj.ijbiomac.2023.126342&partnerID=40&md5=37a479d35d43efccd4aff328d3ee972a

Herein, the polymer nanomatrix of chitosan/SiO2 (CHI/n-SiO2) was enriched with a π-π electron donor-acceptor system using diaromatic rings of benzil (BEZ) assisted via a hydrothermal process to obtain an effective adsorbent of chitosan-benzil/SiO2 (CHI-BEZ/n-SiO2). The polymer nanomatrix (CHI/n-SiO2) and the resulting adsorbent (CHI-BEZ/n-SiO2) were applied to remove the anionic acid red 88 (AR88) dye from aqueous media in a comparative mode. Box-Behnken design (BBD) was adopted to optimize AR88 adsorption onto CHI/n-SiO2 and CHI-BEZ/n-SiO2 with respect to variables that influence AR88 adsorption (adsorbent dose: 0.02–0.1 g/100 mL; pH: 4–10; and time: 10–90). The adsorption studies at equilibrium were conducted with a variety of initial AR88 dye concentrations (20–200 mg/L). The adsorption isotherm results reveal that the AR88 adsorption by CHI/n-SiO2 and CHI-BEZ/n-SiO2 are described by the Langmuir model. The kinetic adsorption profiles of AR88 with CHI/n-SiO2 and CHI-BEZ/n-SiO2 reveal that the pseudo-first-order model provides the best fit results. Interestingly, CHI-BEZ/n-SiO2 has a high adsorption capacity (261.2 mg/g), which exceeds the adsorption capacity of CHI/n-SiO2 (215.1 mg/g) that relates to the surface effects of SiO2 and the functionalization of chitosan with BEZ. These findings show that CHI-BEZ/n-SiO2 represents a highly efficient adsorbent for the removal of harmful pollutants from water, which outperforming the CHI/n-SiO2 system. © 2023 Elsevier B.V.