Synthesis and characterization of citric acid-modified chitosan Schiff base with enhanced antibacterial properties for the elimination of Bismarck Brown R and Rhodamine B dyes from wastewater

• Published in: International journal of biological macromolecules 2024-04, Vol.264 (Pt 1), p.130664-130664, Article 130664
• Main Authors: Pawariya, Varun, De, Soumik, Dutta, Joydeep
• Format: Article
• Language: English
• Subjects: Antibacterial activity; Chitosan Schiff base; Citric acid; Dye removal; Wastewater
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.130664

In this study, a new chitosan Schiff base with surface modification using citric acid was synthesized for efficient removal of pernicious dyes, namely Bismarck Brown R (BBR) and Rhodamine B (RhB), from wastewater. The physicochemical properties of the modified chitosan Schiff base were comprehensively investigated. Adsorption studies demonstrated that BBR adsorption occurred through monolayer formation, while RhB adsorption proceeded via multilayer formation on the heterogeneous surface. The synthesized adsorbent exhibited exceptional dye removal efficiency, with a Langmuir saturation capacity of 348 ± 11.0 mg.g−1 for BBR and 145 ± 18.44 mg.g−1 for RhB. Isotherm data fitting revealed consistency with the Langmuir isotherm model for BBR and the Freundlich isotherm model for RhB. Notably, the modified chitosan Schiff base showcased enhanced antibacterial properties, effectively inhibiting both gram-positive and gram-negative bacteria. The study's findings underscore the potential of this novel chitosan-based Schiff base as an efficient adsorbent for the removal of various dyes from wastewater, emphasizing its versatility and practical applicability in water treatment processes. [Display omitted] •A citric acid modified Chitosan SB was synthesized to remove BBR and RhB dyes from wastewater.•Langmuir saturation capacity was found to be 348 ± 11.0 mg/g for BBR and 145 ± 18.44 mg/g for RhB.•Pseudo second order kinetic model governs the rate of adsorption.•Antibacterial activity against gram positive and gram negative bacteria has been determined.