ABSTRACT
Coagulation-flocculation is an important process in water treatment plants. Recent studies have shown the potential of condensed tannins for the production of coagulants of natural origin, as an alternative to chemical coagulants. The present study highlights the importance of the development of nature-based solutions that can be alternative to conventional processes and is focused on optimizing the process of extraction of condensed tannins from Acacia dealbata bark as a strategy for the valorization of forest residues. Under the conditions tested, the highest extraction yield was obtained at a temperature of 40 °C, using ethanol 50% (v/v) as a solvent and an extraction time of 30 min, without stirring. The highest concentrations of condensed tannins and phenolic compounds were detected in samples of Acacia sp. with greater vegetative development (trunk perimeter of 20 cm), corresponding to 246.2 ± 9.4 and 706.2 ± 27.2 milligrams per gram of dry extract, respectively.
