Synthesis of chitosan-ethylene glycol diglycidyl ether/TiO2 nanoparticles for adsorption of reactive orange 16 dye using a response surface methodology approach

[Display omitted] •A crosslinked chitosan-EGDE/TiO2 nanoparticle was synthesized.•A crosslinked chitosan-EGDE/TiO2 nanoparticle was applied for RO16 removal.•BBD with RSM was applied to optimize the adsorption parameters.•The adsorption capacity for RO16 dye was 1407.4 mg/g. Chitosan-ethylene glycol diglycidyl ether/TiO2 nanoparticles (CS-EGDE/TNP) composite was synthesized to be biosorbent for the removal of reactive orange 16 (RO16) dye from aqueous solution. The CS-EGDE/TNP composite was characterized via BET, XRD, FTIR, and SEM-EDX techniques. Response surface methodology (RSM) with Box–Behnken design (BBD) was applied to optimize the adsorption key parameters such as adsorbent dose (A: 0.02–0.08 g/L), RO16 dye concentration (B: 20–80 mg/L), solution pH (C: 4–10), temperature (D: 30–50 °C), and contact time (E: 30–90 min). The adsorption isotherm followed Freundlich model and pseudo-second order (PSO) kinetic model. The adsorption capacity of CS-EGDE/TNP for RO16 dye was 1407.4 mg/g at 40 °C. The adsorption mechanism of RO16 dye on the surface of CS-EGDE/TNP can be attributed to various interactions such as electrostatic attraction, n-π interaction, Yoshida H-bonding, and H-bonding. Results supported the potential use of CS-EGDE/TNP as effective adsorbent for the treatment of acid reactive dye.