Optimized Hydrothermal Synthesis of Chitosan-Epichlorohydrin/Nanosilica for Efficient Reactive Dye Removal: Mechanistic Insights

• Published in: Water, Air, and Soil Pollution
• Main Author: Wu R.; Abdulhameed A.S.; Selvasembian R.; Yousif E.; ALOthman Z.A.; Jawad A.H.
• Format: Article
• Language: English
• Published: Springer Nature 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85186440908&doi=10.1007%2fs11270-024-06943-7&partnerID=40&md5=fb94439095ccd543b1c0e137e2c1ecd9

In this study, a cross-linked chitosan-epichlorohydrin/nanosilica (CS-EPH/NSi) bionanocomposite was prepared using a simple two-step process. First, functionalization of chitosan with nanosilica followed by crosslinking process with epichlorohydrin. The CS-EPH/NSi bionanocomposite’s adsorption property toward the removal of reactive orange 16 (RO16) dye was evaluated. The adsorption process of RO16 by CS-EPH/NSi was optimized using Box-Behnken design (BBD). The desirability function results revealed that the highest removal of RO16 (96.32%) is achieved at the following experimental conditions: solution pH of 4.26, dosage of CS-EPH/NSi = 0.089 g/100 mL, and contact time of 9.69 min. The Langmuir isotherm model was found to describe the equilibrium behavior of the monolayer adsorption process at 25 °C. The kinetics data of RO16 adsorption by CS-EPH/NSi were appropriately described by a pseudo-second order model, which suggests that the adsorption process occurs via chemisorption. The high adsorption capacity of CS-EPH/NSi for RO16 (110.2 mg/g) can be attributed to the electrostatic forces between the positively charged CS-EPH/NSi and the negatively charged RO16 anions, as well as n-π and H-bond interactions. Overall, this study demonstrates the potential of CS-EPH/NSi as an adsorbent for the efficient removal of textile RO16 dye. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.