Competitive adsorption of dye metanil yellow and RB15 in acid solutions on chemically cross-linked chitosan beads

• Published in: Chemosphere (Oxford) Vol. 62; no. 5; pp. 731 - 740
• Main Authors: Chiou, Ming-Shen, Chuang, Guo-Syong
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2006; Elsevier
• Subjects: Adsorption; Adsorption capacity; Anionic dyes; Applied sciences; Azo Compounds - chemistry; Azo Compounds - pharmacokinetics; Chitosan - chemistry; Coloring Agents - chemistry; Coloring Agents - pharmacokinetics; Competitive adsorption; Cross-linked chitosan beads; Cross-Linking Reagents - chemistry; Diffusion; Exact sciences and technology; Hydrogen-Ion Concentration; Industrial wastewaters; Kinetics; Langmuir isotherm; Models, Chemical; Organic Chemicals - chemistry; Organic Chemicals - pharmacokinetics; Pollution; Solutions; Textile Industry; Wastewaters; Water treatment and pollution; Adsorption capacity; Anionic dyes; Competitive adsorption; Cross-linked chitosan beads; Langmuir isotherm; Discoloration; Organic dye; Liquid solid adsorption; Natural polymer; Competitive reaction; Organic adsorbent; Chemical reaction kinetics; Operating conditions; Industrial waste water; Reactive dye; Oside polymer; Physicochemical purification; Chitosan; Waste water purification; Ion exchange resin; Acid dye; Organic compounds
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2005.04.068

One kind of adsorbent with a high adsorption capacity for anionic dyes was prepared using ionically and chemically cross-linked chitosan beads. A batch system was applied to study the adsorption behavior of one acid dye (MY, metanil yellow) and one reactive dye (RB15, reactive blue 15) in aqueous solutions by the cross-linked chitosan beads. The adsorption capacities was 3.56 mmol g −1 (1334 mg g −1) for dye MY and 0.56 mmol g −1 (722 mg g −1) for dye RB15 at pH 4, 30 °C. The Langmuir model agreed very well with the experimental data ( R 2 > 0.996). The kinetics of adsorption for a single dye and the kinetics of removal of ADMI color value in mixture solutions at different initial dye concentrations were evaluated by the nonlinear first-order and second-order models. The first-order kinetic model fits well with the dynamical adsorption behavior of a single dye for lower initial dye concentrations, while the second-order kinetic model fits well for higher initial dye concentrations. The competitive adsorption favored the dye RB15 in the mixture solution (initial conc. (mM): MY = 1.34; RB15 = 1.36); while it favored the dye MY in the mixture solution (initial conc. (mM): MY = 3.00; RB15 = 1.34) and the adsorption kinetics for dye RB15 has the tendency to shift to a slower first order model.