A NOVEL APPLICATION OF BENTONITE MODIFIED WITH COPPER IONS IN THE TETRACYCLINE ADSORPTION: AN EXPERIMENTAL DESIGN STUDY

Abstract The adsorption of tetracycline (TC) on bentonite treated with copper ions was studied and compared to natural bentonite's adsorption capacity, analyzing the influence of different factors: copper salt, pH and concentration. Results showed that Cu-bentonites increase the adsorption of TC, predominately by complexation and hydrogen bonds. The interaction (-1) between pH and salt type favored the TC adsorption, while the concentration does not have statistical influence. The best sample of Cu-Bent was able to remove 98.23% of TC in solution. This sample was treated with copper nitrate in an acidic medium. In conclusion, the results indicate that Cu-Bent may represent a low-cost and sustainable strategy to remove TC, a contaminant with emerging concern.