title: Biosorption of metal ions using a low cost modified adsorbent (Mauritia flexuosa): experimental design and mathematical modeling.
abstract: Buriti fibers were subjected to an alkaline pre-treatment and tested as an adsorbent to investigate the adsorption of copper, cadmium, lead and nickel in mono- and multi-element aqueous solutions, the results showed an increase in the adsorption capacity compared to the unmodified Buriti fiber. The effects of pH, adsorbent mass, agitation rate and initial metal ions concentration on the efficiency of the adsorption process were studied using a fractional 2(4-1) factorial design, and the results showed that all four parameters influenced metal adsorption differently. Fourier transform infrared spectrometry and X-ray fluorescence analysis were used to identify the groups that participated in the adsorption process and suggest its mechanisms and they indicated the probable mechanisms involved in the adsorption process are mainly ion exchange. Kinetic and thermodynamic equilibrium parameters were determined. The adsorption kinetics were adjusted to the homogeneous diffusion model. The adsorption equilibrium was reached in 30 min for Cu(2+) and Pb(2+), 20 min for Ni(2+) and instantaneously for Cd(2+). The results showed a significant difference was found in the competitiveness for the adsorption sites. A mathematical model was used to simulate the breakthrough curves in multi-element column adsorption considering the influences of external mass transfer and intraparticle diffusion resistance.
authors.affiliation: a Department of Chemistry , Federal Institute of Education and Science of Piauí , Paulistana , Brazil.|b Department of Analytical Chemistry and Physical Chemistry , Federal University of Ceará , Fortaleza , Brazil.
authors.forename: Diego de Quadros
authors.initials: Dde Q
authors.lastname: Melo
authors.affiliation: c Department of Hydraulic and Environmental Engineering , Federal University of Ceará , Fortaleza , Brazil.
authors.forename: Carla Bastos
authors.initials: CB
authors.lastname: Vidal
authors.affiliation: b Department of Analytical Chemistry and Physical Chemistry , Federal University of Ceará , Fortaleza , Brazil.
authors.forename: Thiago Coutinho
authors.initials: TC
authors.lastname: Medeiros
authors.affiliation: c Department of Hydraulic and Environmental Engineering , Federal University of Ceará , Fortaleza , Brazil.
authors.forename: Giselle Santiago Cabral
authors.initials: GS
authors.lastname: Raulino
authors.affiliation: d Department of Environmental Engineering , Fronteira Sul Federal University , Erechim , Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Dervanoski
authors.affiliation: d Department of Environmental Engineering , Fronteira Sul Federal University , Erechim , Brazil.
authors.forename: Márcio do Carmo
authors.initials: Mdo C
authors.lastname: Pinheiro
authors.affiliation: b Department of Analytical Chemistry and Physical Chemistry , Federal University of Ceará , Fortaleza , Brazil.|c Department of Hydraulic and Environmental Engineering , Federal University of Ceará , Fortaleza , Brazil.
authors.forename: Ronaldo Ferreira do
authors.initials: RF
authors.lastname: Nascimento
mesh_terms: D000327:Adsorption; D028023:Arecaceae / Q000737:chemistry*; D003198:Computer Simulation; D007700:Kinetics; D008670:Metals / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D012107:Research Design; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D018508:Water Purification
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical
keywords: Biosorption; Buriti fibers; characterization materials; mathematical modeling; metal ions; numerical simulation