Utilização da argila bentonita como adsorvente para a remoção de níquel em efluentes industriais sintético

Abstract

The growing development of industries in recent years has caused serious environmental damage. One of the main industrial processes has generated effluents with the presence of ions is electroplating. The most used methods for the treatment of industrial effluents involve physical or chemical processes, an option for this process is the use of clays, which contain high operating capacity and obtain high quality effluents. Recent studies regarding the use of clay in the adsorption processes are due to the favorable intrinsic properties of the material: large specific surface area, excellent physical stability, low cost and good facility of ion exchange. The objective of the monography is to characterize the natural bentonite clay PMT3 using techniques such as: x-ray diffraction (DRX) and infrared absorption spectroscopy (FT-IR), to determine the best adsorption conditions for the nickel nitrate by bentonite clay and carry out the study of adsorption isotherms. The experiment was carried out using the factorial design methodology 2² + 3 central points (study variables: nickel concentration (80, 130 and 180 mg / L) and pH (4, 6, 8). The software Statistica 7.0 was used to analyze the data and develop the statistical model. The adsorption isotherm, at room temperature, presented a curve similar to the type II presented by BET, being the most common model in the adsorption processes. The best model that represented the process was Freundlich's with an R² value of 0.9725 and an n value of 2.59, indicating a favorable adsorption process. According to the study, bentonite clay is efficient in removing the nickel content in industrial effluents, being an alternative for this treatment.