Adsorption of methylene blue dye on construction and demolition waste in an aqueous medium

Abstract

Abstract The present research proposed the use of construction and demolition waste (CDW) in adsorption of methylene blue dye in aqueous medium. CDW was studied in its natural form and calcined aiming to improve its properties, both being characterized by different techniques and subjected to adsorption studies. From the kinetic study, it was verified that both systems presented a better fit to the experimental data for the pseudo-second-order model (R2 >0.980). The concentration and temperature variation showed a maximum adsorption capacity of 112.23 mg.g-1 (natural) and 418.6 mg.g-1 (calcined) both for the temperature of 45 ºC. The experimental data fit better with the Langmuir isotherm model, with a correlation coefficient R2 ≥0.960 for both samples. It was observed that both residues presented favorable adsorption mechanisms and effective adsorption parameters, but the calcined sample presented better results, and thinking in a low-cost material, natural sample can be more economically advantageous. In this view, CDW represents a potential and promising alternative for water purification.

Keywords

• adsorption
• methylene blue dye
• construction and demolition waste