Adsorção de corante azul de metileno em argila plástica 'Ball Clay'

Abstract

The presence of synthetic dyes in the waters, from their incorrect discharge, besides generating the change in color, promotes a delay in the process of photosynthesis, facilitating the formation of foams on the surface, which causes a reduction in the oxygen transfer rate, causing the death of several species of animals and plants. This research aimed to study the potential of using ball clay from the city of Oeiras-PI as an adsorbent material of the methylene blue dye, analyzing an impact of the heat treatment, especially at 200°C, of the clay material in the adsorptive process through the development of kinetic models according to studies carried out by Rao and Kashifuddin (2012). In addition, we seek to understand the action of potassium acetate interpolation in ball clay for the purposes of dye adsorption based on procedures adopted by Gardolinski (2001) and Oliveira (2012). The studied clay presented kaolinite, quartz and mica as the main mineralogical constituents. The thermal activation caused a change related to the intensity of some kaolinite peaks. The dye interacted with samples (natural and intercalated) at the solid/liquid interface. Were applied two kinetic models, the Pseudosecond model being the one that best adjusted to the experimental data, presenting the minimum time of 90 minutes to reach equilibrium. The thermal parameters have great spontaneous and endothermic reactions for natural clays, and not spontaneous and exothermic for interleaved clays. The best results of adsorption of methylene blue occurred at a temperature of 80ºC in the natural clay heat treated at 200ºC, with a total of 2,191,700 mg / g. In three cycles, the same sample showed adsorption efficiency of 70.5% and desorption of 66.8%.