Silva, Hérika Cavalcante Dantas daSantiago, Vanessa de Oliveira Borges2022-02-172022-02-172022-02-14SANTIAGO, Vanessa de Oliveira Borges. Fitotoxicidade de efluentes da estação de tratamento da UFRN em semente de Lactuca Sativa. 2022. 28f. Trabalho de Conclusão de Curso (Graduação em Engenharia Ambiental) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2022.https://repositorio.ufrn.br/handle/123456789/46024Effluent treatment aims to reduce the contaminants that are present and protect public and environmental health, by removing contaminants, nutrients and pathogens so that treated water can be reused for various purposes. The present work sought to develop an analysis of the phytotoxicity of effluents from the Sewage Treatment Station (ETE) of the Federal University of Rio Grande do Norte in lettuce seed (Lactuca Sativa), considering that the treated effluent serves to irrigate the fields of football and the entire green area of the university. Therefore, a germination test was carried out by inserting the seeds in a filter paper substrate soaked with treated sewage and raw sewage from the ETE in concentrations of 25%, 50% and 100%. Due to the increase in the contribution of laboratory sewage on campus, to the detriment of the decrease in domestic sewage, with the effluents (raw and treated) from the ETE it was expected that the analyzes would present phytotoxicity and, therefore, the inhibition of lettuce seed growth. Phytotoxicity was evaluated through the Germination Index (GI) and the Relative Growth Index (ICR) of the radicle of the test organism, where the ICR values were analyzed in three different categories according to the toxicity effects: elongation inhibition (I), 0<x<0.8; no significant effects (SES), 0.8≤x≤1.2; and elongation stimulation (E), x>1.2, being verified that all the results of both the raw and the treated effluent had values above 0.8, going against the hypothesis addressed. The results of the treated effluent for the 50% and 100% concentrations were lower than those for the 25% concentration, which presupposes that some chemical agent was in excess in the collected sample, possibly chlorine, since it is used for disinfection of drinking water. reuse, especially for irrigation purposes. Therefore, further analysis and studies of the toxic effects of this water on the aquatic ecosystem are necessary due to excess chlorine, there is a possible formation of potentially carcinogenic halogen compounds that can contaminate water sources (water table) after infiltration into the soil, well with studies using organisms - tests of different trophic levels that can present a greater sensitivity and allow to identify the toxic effects that were not observed with the species tested in this study.EcotoxicidadeEfluentesÍndice de germinaçãoÍndice de crescimento relativoEcotoxicityEffluentsGermination indexRelative growth indexbachelorThesis