Adsorção de corante azul reativo 222 em carvão ativado produzido a partir do bagaço da cana-de-açúcar

Abstract

The increased public demand for products and services bring together the effluent and residue generation versus new treatment techniques issue. Aiming a solution to this problem, the present study proposes a method of activated carbon production from sugar cane mills residues. The obtained material can be used in the adsorption of Reactive Blue 222 in aqueous phase, simulating a real effluent from jeans fabric dyeing on textile industries. Starting with chemical and physical substrate activation processes, followed by characterization, it is possible to determinate the dye’s adsorption kinetics, in addition to the adsorption isotherm adjust by the Langmuir and Freundlich methods. The influence caused by different pH values was also observed. The characterization of raw materials indicated 6,9% of humidity, ash content equivalent to 1,2% and 53,87% by ash mass of ashes insoluble in acid medium. Analyzing carbon properties, it was found that the carbon activated with NaOH had larger specific area than the commercial one, highlighting its better color removal efficiency. By dye’s adsorption kinetics trials, it was found a stabilizing time corresponding to 4 hours. In this condition, the quantity of adsorbed dye was 18.52 mg of dye per gram of adsorbent. Assessing the pH effect on system operation, it was discovered that in alkaline mediums, the process showed slightly more efficiency. Analyzing the type of isotherm that showed the best fit to the experimental data, it was defined that Freundlich isotherm had the best representation. In general, this experiment contributes effectively to the understanding of adsorption processes.