DANTAS, S. L. A; http://lattes.cnpq.br/3881519277514571; DANTAS, Suylan Lourdes de Araújo.
Abstract:
This study aimed to develop a low cost material for sorption of dyes in industrial
effluents from chitosan, studies in order to determine the optimum parameters and
mechanisms involved in that process. The use of kinetic models had the order to
elucidate the nature of the sorption processes. The characterization of the biopolymer
techniques were used to pigmentary, conductometric titration, infrared spectroscopy,
differential thermal analysis, thermal analysis, differential scanning calorimetry and
scanning electron microscopy. The retention of dyes from aqueous solutions on chitosan
was evaluated using sorption tests, the method of finite bath, at a predefined pH value at
different times of contact sorbent: sorbate. The concentrations of dye samples studied,
as well as their supernatants after sorption tests were determined by UV-Visible
spectroscopy. In the study of the kinetics of retention of the supernatant, the values of
reaction order was determined by models of integrated reaction rates of first and second
order. The removal of dyes can be regarded as a process of electrostatic adsorbent-
adsorbate interaction, considering the pH range of the reaction medium. The results
suggest that chitosan has application as an effective adsorbent to remove dyes in
wastewater, particularly those of acidic nature, according to the values determined in the
reaction kinetics, we can identify the dye methyl orange dye which was obtained better
performance compared to adsorption experiments with the chitosan membrane, taking
into account the contact times studied. This is mainly due to nature of the adsorbate.
Because it is classified as a basic dye, crystal violet did not show how to interact
effectively adsorb to the chitosan membrane.