Synthesis and Characterization of Boehmite Particles Obtained from Recycling: Water Disinfection Application

Abstract

We report on the synthesis of boehmite aluminum oxide hydroxide particles with lamellar structure (γ-AlO(OH)) obtained from the recycling of metallic can seals, with the addition of silver nanoparticles (Ag-NPs) reduced by Aloe Vera extract. X-ray diffractometry (XRD) confirmed the γ-phase, and scanning electron microscopy (SEM) showed the presence of Ag-NPs on the boehmite particle surface, confirming the efficiency of the synthesis to obtain the composite material. The samples were used to treat lake water, according to the Standard Methods for the Examination of Water and Wastewater. The results indicated that the elimination of total coliforms and Escherichia coli occurred, with excellent efficiency for the Ag-boehmite sample. The tests show the possibility of reuse (5×) of the sample, as it maintained the efficiency of disinfection for E. coli. The preparation, use, and reuse of boehmite obtained from metallic waste is a case of a circular economy, focused on sustainability and green chemistry.

Mixed oxides with corundum-type structure obtained from recycling can seals as paint pigments: color stability

“…The pH value was modified to obtain the boehmite phase by adding sodium hydroxide (NaOH) until pH 8. After precipitation, the oxide hydroxide was vacuum filtered and oven-dried at 70 °C [ 1 , 13 ].…”

“…Purification was performed by washing the synthesized samples with hot water to remove sodium chloride. After this step, the boehmite was filtered and dried at 70 °C [ 1 , 13 ].…”

“…In this way, green is the perfect contrast to red, as they are complementary colors in well-established chromatic models. Thus, green takes on the opposite meaning of danger, namely safety [ 13 ]. Therefore, it is essential to have color intensity and stability to avoid aging in signalization, for example, in motor roads, chemical industries, and hospitals.…”

Color stability of blue aluminates obtained from recycling and applied as pigments

“…Aer this step, the boehmite was ltered and dried at 70 °C. 17,23 To obtain the white sample, the boehmite was calcined at 1000 °C.…”