Avaliação da atenuação da toxicidade de lodo de esgoto por associação com resíduo vegetal da indústria sucro-alcooleira

• Autor(a) principal: Sommaggio, Lais Roberta Deroldo [UNESP]
• Data de Publicação: 2013
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/121366
• topic: Esgoto; Toxicologia; Toxicidade - Testes; Bioquímica; Lodo esgoto; Residuos vegetais; Biorremediação

Sewage sludge (SS) is a semi-solid residue generated in the sewage treatment process. Due to a stricter environmental legislation, the production of SS has increased. In order to propose a more effective destination for this residue, authors suggest its use as agricultural input, which can characterize it as an interesting resource from the economic and environmental viewpoint. However, SS can contain toxic substances and pathogenic microorganisms that prevent its use in agriculture. One solution for the reduction of its toxic potential is to submit it to bioremediation with the introduction of stimulating agents. Sugarcane bagasse (B) can be used as soil decompressing, since it favours a better porosity in the medium and better anaerobiosis to the system, ideal characteristics for the contaminants bioremediation. In this experiment, vats containing samples of SS100%; SS+B (3:1-v/v); SS+Soil (3:1-v/v); SS+B+Soil (3:1:1-v/v/v) were used. The samples were bioremediated for 1 (T1), 3 (T2) and 6 months (T3). After each period, the cytotoxic, genotoxic and mutagenic potentials of the different solid samples, solubilized of these samples and the water that percolated from them were assessed by assays with Allium cepa test organism. A microbiological analysis of the SS and its associations was performed after each period tested. In relation to the cytotoxic effects analysis, evaluated by the mitotic index, the solid samples of SS+B presented, for all the periods, significant decrease of cell division, as well as the solid sample of SS 100% for T3. For the solubilized, a cytotoxic effect was only observed for the samples SS+B in T1, SS 100% in T2 and SS+B+S in T3. For the percolated samples, there was no cytotoxic effect. For the genotoxicity parameter (quantification of chromosome and nuclear alterations) only the solid sample of SS+B was genotoxic. Regarding the mutagenicity (assessed by the presence of chromosome breaks and micronuclei), no...