Uso de biocarvão impregnado com alumínio reciclado para remoção de contaminantes ambientais

Abstract

Aluminum is an element used widely in contemporary life. An increasing amount of aluminum is being leached continuously by acid rain and contributes significantly to environmental impacts. Projects that seek to apply aluminum waste in other areas have been a reality for many years, including in Brazil. In parallel with the aluminum disposal, the presence of nutrients, such as phosphorus (P), in water bodies represents a problem for water quality, including eutrophication, which is considered a serious environmental impact. Among the tertiary effluent treatment technologies available for the removal of soluble phosphorus, adsorption has been investigated because it is a relatively simple process that allows the nutrient to be recycled. Methods that increase the adsorption capacity of the adsorbent to remove P, such as aluminum impregnation, have been investigated. The general objective of this work was to obtain samples of biochar impregnated with aluminum obtained from recycled waste for application in phosphate removal. Therefore, a preliminary study was carried out to define the impregnation method that resulted in the highest phosphorus adsorption capacity. The impregnation of Al in biochar took place in two different ways, the first through a solution of aluminum chloride, and the second through the mixture with aluminum oxide. The physical and chemical characterization of the samples was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), thermogravimetric analysis (TGA) and elemental analysis. Other analyzes that were of great importance for the elaboration of this research are X-Ray Diffrometry (XRD), Thermogravimetric Analysis (TG) and Fourier Transform Infrared Spectroscopy (FTIR). In the elemental composition of both samples, Cl, Al, Fe, Ca, K, Mn and S were detected, in addition to H, C and N, differing only in the proportion of each element. After performing the adsorption by the BET method, it was observed that the samples are framed within the classification of mesopores and this type of pore provides high capacity a high adsorption capacity of molecules with small dimensions and are useful for liquid-solid adsorption.