INVESTIGADORES
CANDAL Roberto Jorge
congresos y reuniones científicas
Título:
Adsorption of crystal violet on montmorillonite: in situ kinetic adsorption and structural complexes formation studies
Autor/es:
MARCO BROWN J.L.; GUZ LUCAS; SCHAMPERA B.; TORRES SANCHEZ R M; CANDAL R.J.
Lugar:
San Martín
Reunión:
Simposio; 5th International symposium on Environmental Biotechnology and Engineering; 2016
Institución organizadora:
ABIAER
Resumen:
Waste water treatment is one of the environmental problems that concern the modern industrial society. In particular, the disposition of colored effluents produced by industries represents a technological problem. There are several types of commercial dyes, being crystal violet (CV) a good model to represent cationic dyes. Adsorption processes have been proposed as a fast alternative to remove contaminants from water. Natural clays are interesting materials to be used as adsorbents, due to its abundance, low cost and high adsorption capacity. In particular, the laminar clay montmorillonite was successfully used in the adsorption of CV1. In view of this background, the aims of the present work are to study the CV adsorption kinetic on montmorillonite (Mt) and the structure of the complexes Mt-CV.In situ CV adsorption kinetic on Mt was evaluated by ATR-FTIR method2, preparing a Mt thin film over the ATR crystal. CV-Mt complexes were prepared by dispersing Mt in CV solutions; the final solids were obtained by centrifugation. The solids were characterized by SAXS; surface charge and wettability were determined using a particle charge detector (PCD) and a dynamic contact-angle tensiometer respectively and N2 adsorption-desorption isotherms were obtained.CV adsorption kinetics study was carried out varying the initial concentration of CV (50, 100, 150, 250 and 500 mgL-1) and experimental data were adjusted by pseudo first (PFO) and second (PSO) order, intraparticle diffusion (IDM) and mixed surface reaction and diffusion-controlled kinetic (MSR/DCK) models. The adsorption kinetic was completed in 30-80 min depending on the initial CV concentration. The entrance of the CV in the basal space of the Mt was determined by SAXS. Specific surface area and porosity were evaluated from N2 adsorption-desorption isotherms. A dependence of the CV molecule orientation into the basal space and surface area with CV initial concentration were found. CV entrance in the Mt basal space and its adsorption at the Mt external surface were confirmed by PCD and contact-angle techniques.