Otimização e estudo da adsorção de corante azul de metileno utilizando carvão ativado subproduto da pirólise do lodo de esgoto

Abstract

The dyes present diverse applications in the various sectors of the industry, such as: textile, food, pharmaceutical and paper. The methylene blue dye used in paper production and as a laboratory scale indicator, depending on its concentration, can have a number of negative effects on aquatic life. The objective of this work was to perform a study and optimization of the adsorption of methylene blue in solution using activated carbon with hydrochloric acid obtained from the pyrolysis of domestic sewage sludge.The adsorption with coal of the pyrolysis of biomass has become a high cost option for the treatment of gaseous and liquid effluents containing dyes and other pollutants, since it is a low cost and simple technique. The methylene blue adsorption studies were carried out in a batch using a 125 ml Erlenmeyer flask and a shaker with 20 mg of the adsorbent and 20 ml of methylene blue solution at a concentration of 10 mg L -1 with rotation of 100 rpm. The parameters evaluated were: pH (2, 4 and 10) and temperature (15, 20 and 25 ° C). An experimental, kinetic and adsorption isotherm planning was elaborated. The adsorption capacity of the coal against the methylene blue was 95.6%, obtained at a temperature of 25 ° C, pH = 10, and adsorption time of 24h. The Langmuir models and the pseudo-second order adsorption model were the best ones that adapted to the experimental results.