Functionalization of Chitosan Biopolymer with SiO Nanoparticles and Benzaldehyde Via Hydrothermal Process for Acid Red 88 Dye Adsorption: Box-Behnken Design Optimization

An effective hydrothermally prepared chitosan-benzaldehyde/SiO adsorbent (CTA-BZA/SiO) employed functionalization of a CTA biopolymer with SiO nanoparticles and BZA. CTA-BZA/SiO is an adsorbent that was utilized for the adsorption of an acidic dye (acid red 88, AR88) from synthetic wastewater. The fundamental adsorption variables (A: CTA-BZA/SiO dosage (0.02-0.1 g); B: pH (4-10); and C: duration (10-60)) were optimized via the Box-Behnken design (BBD). The Langmuir and Freundlich isotherms (coefficients of determination R = 0.99) agreed well with empirical data of AR88 adsorption by CTA-BZA/SiO. The pseudo-first-order model showed reasonable agreement with the kinetic data of AR88 adsorption by CTA-BZA/SiO. The maximal AR88 adsorption capacity (q) for CTA-BZA/SiO was identified to be 252.4 mg/g. The electrostatic attractions between both the positively charged CTA-BZA/SiO adsorbent and the AR88 anions, plus the n-π, π-π, and H-bond interactions contribute to the favourable adsorption process. This study reveals that CTA-BZA/SiO has the capacity to be a suitable adsorbent for the removal of a wider range of organic dyes from industrial effluents.