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

• Published in: WATER AIR AND SOIL POLLUTION
• Main Authors: Wu, Ruihong; Abdulhameed, Ahmed Saud; Selvasembian, Rangabhashiyam; Yousif, Emad; Alothman, Zeid A.; Jawad, Ali H.
• Format: Article
• Language: English
• Published: SPRINGER INT PUBL AG 2024
• Subjects: Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001158152100001

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 degrees 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-pi 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.