Tunable Schiff's base-cross-linked chitosan composite for the removal of reactive red 120 dye: Adsorption and mechanism study

• Published in: International Journal of Biological Macromolecules
• Main Author: Jawad A.H.; Mubarak N.S.A.; Abdulhameed A.S.
• Format: Article
• Language: English
• Published: Elsevier B.V. 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076571473&doi=10.1016%2fj.ijbiomac.2019.10.014&partnerID=40&md5=195be6ba9755c8a1111071778217830b

In this study, tunable Schiff's base-cross-linked chitosan-glutaraldehyde (CS-GLA) was modified and applied to remove reactive red 120 (RR120) dye from an aqueous solution. Different ratios of TiO2 nanoparticles, such as 25% TiO2 nanoparticles (CS-GLA/TNC-25) and 50% TiO2 nanoparticles (CS-GLA/TNC-50), were loaded into the CS-GLA's molecular structure. The adsorptive properties of CS-GLA, CS-GLA/TNC-25, and CS-GLA/TNC-50 for the RR120 dye in the aqueous solution were evaluated. CS-GLA/TNC-25 exhibited the best adsorptive property possibly because of the perfect balancing between the surface area and available amine ([sbnd]NH2) groups in the composite formulation. The impact of adsorption key parameters, such as adsorbent dosage (0.01–1.2 g), RR120 dye concentration (30–400 mg/L), solution pH (3–12), and contact time (0–400 min) were explored by batch adsorption mode. The adsorption was well described by the Freundlich model and pseudo-second order kinetic model. The adsorption capacity of CS-GLA/TNC-25 for RR120 dye was 103.1 mg/g at 303K. The adsorption mechanism of RR120 on the CS-GLA/TNC-25 surface can be assigned to various interactions, such as electrostatic attraction, n–π stacking, and H-bonding. Results indicate the potential application of CS-GLA/TNC-25 as environment-friendly biosorbent for removing acid and/or textile dyes, such as RR120, from aqueous environments. © 2019 Elsevier B.V.