title: Competitive adsorption of dye metanil yellow and RB15 in acid solutions on chemically cross-linked chitosan beads.
abstract: 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 pH4, 30 degrees 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.
authors.affiliation: Department of Chemical Engineering, National United University, Miao Li 360, Taiwan, ROC. chiou@nuu.edu.tw
authors.forename: Ming-Shen
authors.initials: MS
authors.lastname: Chiou
authors.forename: Guo-Syong
authors.initials: GS
authors.lastname: Chuang
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry* / Q000493:pharmacokinetics; D048271:Chitosan / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry / Q000493:pharmacokinetics; D003432:Cross-Linking Reagents / Q000737:chemistry; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D009930:Organic Chemicals / Q000737:chemistry* / Q000493:pharmacokinetics; D012996:Solutions; D013783:Textile Industry
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D003432:Cross-Linking Reagents; D009930:Organic Chemicals; D012996:Solutions; C449191:reactive blue 15; C005108:metanil yellow; D048271:Chitosan