Carnaval, Tatiane Kelly Barbosa de AzevedoNascimento, Paula Evanyn Pessoa do2025-01-232025-01-232025-01-10NASCIMENTO, Paula Evanyn Pessoa do. Taninos extraídos de casca de anacardium occidentale com hidróxido e sulfito de sódio podem ser eficientes no tratamento de água? 2025. 46f. Trabalho de Conclusão de Curso (Graduação em Engenharia Florestal) – Universidade Federal do Rio Grande do Norte, Unidade Acadêmica Especializada em Ciências Agrárias, Curso de Graduação em Engenharia Florestal, Macaíba, 2025.https://repositorio.ufrn.br/handle/123456789/61817Plant tannins are water-soluble phenolic compounds capable of precipitating proteins, gelatin, and alkaloids. The extraction process is crucial as it can alter their properties and structure. Studies indicate that the addition of compounds such as sodium hydroxide and salts facilitates the extraction of tannins from plant bark. In water treatment, tannins stand out as natural coagulants, offering environmental and operational advantages compared to chemical coagulants. This study aims to optimize the extraction of tannins from the bark of the cashew tree (Anacardium occidentale) and explore their application in water treatment, contributing to technological advancements. For the research, samples were collected from five Anacardium occidentale trees at the Agricultural School of Jundiaí (EAJ) of the Federal University of Rio Grande do Norte (UFRN). The extraction of tannic substances from the bark was conducted using three samples, each consisting of 25 g of fully dried bark per treatment. The bark samples were subjected to extraction using pure water and water containing sodium hydroxide (NaOH) and sodium sulfite (Na₂SO₃) at different concentrations. The total solids content (TST), Stiasny index (I), and condensed tannin content (TTC) were evaluated. The extracted tannins were cationized and subsequently applied in the water treatment process using a Jar-test apparatus. Two concentrations were tested: 150 mg/L and 200 mg/L, with pH and turbidity measured during the process. The study demonstrated that the addition of sodium hydroxide and sodium sulfite in the extraction of condensed tannins from the bark of Anacardium occidentale was effective, with distilled water yielding the lowest values across all parameters analyzed. Cationized tannin-based coagulants, when combined with salts, showed promising results in reducing water turbidity while maintaining a minimal difference between the final and initial pH levels.Attribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/extrativos vegetaisplant extractivescajueirocashew treePFNMNTFPsadição de saissalt additionfloculanteflocculantbachelorThesisCNPQ::CIENCIAS AGRARIAS