Enhanced decolorization of dyes by an iron modified clay and thermodynamic parameters.
The sorption processes of red 5 (R5) and yellow 5 (Y5) dyes by iron modified and sodium bentonite in aqueous solutions was evaluated. The modified clay was prepared, conditioned and characterized. The sodium clay did not remove any of either dye. The sorption kinetics and isotherms of R5 and Y5 dyes by iron modified clay were determined. The maximum removal percentages achieved were 97% and 98% for R5 and Y5, respectively, and a contact time of 72 h; the experimental data were best adjusted to Ho model. The isotherms of both dyes were best adjusted to the Langmuir model and the maximum adsorption capacities of the modified clay were 11.26 mg/g and 5.28 mg/g for R5 and Y5, respectively. These results indicate that adsorption processes have a high probability to be described as chemisorption on a homogeneous material. Temperature range between 283 and 213 K does not affect the adsorption of Y5 by the iron modified clay, but the adsorption process of R5 was affected, and the thermodynamic parameters could be calculated, which indicate a chemisorption mechanism.
Instituto Tecnológico de Toluca, División de Estudios de Posgrado, Av. Tecnológico s/n, Ex Rancho La Virgen, C.P. 52140, Metepec, Estado de México, México.
N
N
Contreras Olivares
Instituto Tecnológico de Toluca, División de Estudios de Posgrado, Av. Tecnológico s/n, Ex Rancho La Virgen, C.P. 52140, Metepec, Estado de México, México.
M C
MC
Díaz-Nava
Departamento de Química, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801, México, D.F., México E-mail: marcos.solache@inin.gob.mx.
M
M
Solache-Ríos
D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001546:Bentonite; D000077215:Clay; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D000538:Aluminum Silicates; D004396:Coloring Agents; D014874:Water Pollutants, Chemical; D001546:Bentonite; D007501:Iron; D000077215:Clay