Potencial tânico do juazeiro (Sarcomphalus joazeiro): uma abordagem de quantificação e sua aplicação no tratamento de água

Abstract

Due to the use of non-biodegradable chemicals in water treatment, it is necessary to search for environmentally friendly products for this process, and plant tannins are a sustainable alternative. Therefore, studying new species to obtain tannins and new parts of the plant that produce tannins is of fundamental importance. In this context, the juazeiro (Sarcomphalus joazeiro), a species endemic to the Caatinga, emerges. Considered evergreen, it is used in medicinal treatments, serves as animal and human food, and is of great economic, social and ecological importance. This research aims to quantify the tannin levels of different parts of the juazeiro, using them as a coagulant for water treatment in order to develop a new natural product. The tannins were extracted from different parts of the juazeiro (bark of the trunk, fruit peel, root and leaves). The total solids content (TST), Stiasny index (SI) and the condensed tannin content (TTC) of the different parts of the plant were determined. The data were processed in the Assistat statistical program, where they underwent a variance analysis at 5% probability. The tannins from the bark underwent the cationization process and were used in the water treatment process, using the Jartest equipment. Using the cationized tannins from the juazeiro bark, at a concentration of 150 mg and two agitation times (130 and 30 RPM), the coagulation test was performed. The same process was performed with a chemical coagulant for the purpose of comparing results. For the TTC, the tannin levels in the different parts of the plant were determined, with 3.4% found in the fruit bark, 1.89% in the leaves, 2.33% in the root and 1.31% in the stem bark. Juazeiro tannins did not show high efficiency in removing turbidity from water, however, they showed promising potential because they did not alter the pH of the water, requiring further research in order to improve the extraction or preparation technique of tannins for use in water treatment or for other purposes.