title: Adsorption studies of methylene blue and gentian violet on sugarcane bagasse modified with EDTA dianhydride (EDTAD) in aqueous solutions: kinetic and equilibrium aspects.
abstract: In this study the adsorption of cationic dyes by modified sugarcane bagasse with EDTA dianhydride (EB) was examined using methylene blue (MB) and gentian violet (GV) as model compounds in aqueous single solutions. The synthesized adsorbent (EB) was characterized by FTIR, elemental analysis, and BET. The capacity of EB to adsorb dyes was evaluated at different contact times, pH values, and initial dye concentrations. According to the obtained results, the adsorption processes could be described by a pseudo-second-order kinetic model. The adsorption isotherms were well fitted by the Langmuir model. Maximum adsorption capacities for MB and GV on EB were found to be 202.43 and 327.83 mg/g, respectively. The free energy change during adsorption of MB and GV was found to be -22.50 and -24.21 kJ/mol, respectively, suggesting that chemisorption is the main mechanism controlling the adsorption process.
authors: Grupo de Química Orgânica e Ambiental, Departamento de Química, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Campus Universitário Morro do Cruzeiro, 35400-000 Ouro Preto, Minas Gerais, Brazil.
authors: Karla Aparecida Guimarães
authors: KA
authors: Gusmão
authors: Leandro Vinícius Alves
authors: LV
authors: Gurgel
authors: Tânia Márcia Sacramento
authors: TM
authors: Melo
authors: Laurent Frédéric
authors: LF
authors: Gil
mesh_terms: D000327:Adsorption; D002412:Cations / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry*; D005840:Gentian Violet / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry; D008962:Models, Theoretical; D031786:Saccharum / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013387:Succinic Anhydrides / Q000737:chemistry*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002412:Cations; D004396:Coloring Agents; D013387:Succinic Anhydrides; D014874:Water Pollutants, Chemical; D002482:Cellulose; C027433:bagasse; D004492:Edetic Acid; D005840:Gentian Violet; D008751:Methylene Blue