Adsorção de azul de metileno de solução aquosa com utilização de pó de serragem de mdf e madeirite e carvão ativado granular

Abstract

The textile industry is characterized of producing wastes with high concentration of dyes because of its dyeing process. To discharge this kind of effluent in the water bodies, a previous treatment for removing the color is necessary. Among the methods for removing color in effluents, the adsorption has been intensively studied to evaluate its efficiency using different alternative materials, such as wood sawdust, that have a low cost, do not require combustion process used to activate the carbon. Thus, the objective of this work was to evaluate the use of sawdust powder of MDF and plywood as adsorbent materials on the removal of methylene blue in the concentration of 0,15 g/L, as an alternative for granular activated carbon. Assays were carried out varying adsorbent masses (1 g, 2 g, 3 g, 4 g, 5 g and 6 g) and pH (5.5, 6.5, 7.5, 8.5, 9.5 and 10.5). Physical-chemical characterization was done determining pH, apparent density, specific density, moisture content and granulometry of sawdust powder of MDF and plywood and granular activated carbon. Results of the assays indicated: acid character for MDF sawdust (pH 4.92 ± 0.07) and neutral character for plywood sawdust (pH 7.08 ± 0.02). It was observed in the adsorption assays: higher efficiencies of dye removal of 98.2% (MDF), 97.9 (plywood) and 100% (granular activated carbon) with adsorbent mass of 6 g; 97.7% (MDF), 98.2% (plywood) and 100% (granular activated carbon) with pH 7.5. It was possible to conclude that MDF and plywood sawdust powder are efficient in the removal of color from aqueous solution containing methylene blue dye by adsorption process.