Evaluation of the adsorption process of remazol black b dye in liquid effluents by green coconut mesocarp

摘要

The textile industry is economically important for the development of Brazil. However, the generated effluents from this activity present a complex molecular structure that gives a recalcitrant characteristic in its residuary waters. Due to this reality, it is necessary to develop viable technologies that remove those compounds, which are mostly dyes. In this study, the green coconut mesocarp was used to remove Remazol Black B dye of an aqueous solution using the adsorption technique. To perform the experiments, the green coconut mesocarp was dried at 60 °C, ground in a grinding mill, sifted, washed with distilled water and immersed in albumin for 24 hours. The process of adsorption was optimized in a batch mode, containing 0.5 g of adsorbent and 25 mL of synthetic solution of 10 mg L~(-1), at 30 °C, pH 4.0, stirring speed of 700 rpm, and granulometry G ￡ 0.149 mm. Afterwards, the influence of the pH of the solution, adsorbent granulometry and stirring speed were evaluated by means of factorial planning. Experiments of equilibrium and kinetics of adsorption were conducted in Erlenmeyer. Results indicated that among the main effects, the pH and the adsorbent granulometry significantly influenced the process of adsorption. Besides, the adsorption equilibrium was reached in 60 minutes of contact. The Langmuir model was adjusted to experimental results (R~2 = 0.9953) being obtained a maximum capacity of adsorption of 2.93 mg g~(-1) and equilibrium constant of 0.26 L mg~(-1). With the obtained results it could be concluded that the green coconut mesocarp could be a viable alternative for the treatment of textile effluents.