1. Repositório Institucional UFC
2. CT - Centro de Tecnologia
3. DEHA - Departamento de Engenharia Hidráulica e Ambiental
4. DEHA - Teses defendidas na UFC

Tipo:	Tese
Título:	Dynamics of metabolites production and application of hydrogen peroxide for the removal of noxious cyanobacteria from isolated cultures and wastewater
Autor(es):	Goes, Marianna Correia Aragão
Orientador:	Capelo Neto, José
Palavras-chave:	Hydrogen peroxide;Cyanobacteria;Metabolites;Stabilization ponds
Data do documento:	2021
Citação:	GOES, Marianna Correia Aragão. Dynamics of metabolites production and application of hydrogen peroxide for the removal of noxious cyanobacteria from isolated cultures and wastewater. 2021. 109 f. Tese (Doutorado Engenharia Civil: Saneamento Ambiental) – Universidade Federal do Ceará, Centro de Tecnologia, Programa de Pós-Graduação em Engenharia Civil: Saneamento Ambiental, Fortaleza, 2021.
Resumo:	The problems caused by the flowering of cyanobacteria in the environment are a worldwide concern. In the case of drinking water, the treatment process to remove cyanobacteria and their intracellular metabolites must be carried out without compromising cell integrity, to avoid exposing consumers to toxins and disinfection by-products. One of these methods is oxidation in situ using hydrogen peroxide (H2O2). The application of H2O2 is a viable alternative, in reservoirs and the effluents of Wastewater Treatment Plants (WTPs), as it is effective in removing cyanobacteria and metabolites and is ecologically correct, as it decomposes quickly into oxygen and water and does not accumulate in the environment. To understand the kinetics of metabolites production and help to predict the best time for application of the oxidant, the concentrations of the metabolites can be predicted by mathematical models from easily measured parameters. Also, it is essential to investigate the occurrence of potentially toxic cyanobacteria in WTPs to assess the potential impact of their effluent on the receiving water bodies. Therefore, this thesis aimed to develop mathematical models to estimate the concentration of metabolites in cyanobacterial species of isolated cultures using easily measurable pigments, to evaluate the effects of H2O2 in these cyanobacterial species and their metabolites, and to investigate the occurrence of toxic cyanobacteria in stabilization ponds in the Brazilian semi-arid region. The equations obtained of multiple regression models were able to predict the concentration of microcystin and geosmin and explained 82.4% and 89.8% of these metabolites in cultures of Microcystis aeruginosa and Dolichospermum circinale, respectively. The application of H2O2 on a bench scale was efficient in suppressing isolated cultures of Microcystis aeruginosa and Dolichospermum circinale cyanobacteria. Dolichospermum circinale cells were visibly more sensitive to H2O2 than Microcystis aeruginosa, since, after the application of 2 mg.L-1, no whole cells were detected. As for the occurrence of toxic cyanobacteria in the stabilization ponds of the Brazilian semi-arid region, the dominance of the species Plankthothrix agardhii, Sphaerocavum brasiliensis and Microcystis aeruginosa was evident, demonstrating that the monitoring of these organisms must be permanent. Based on these results, mathematical modeling can be an important tool to alert the presence of toxins in the water and the need for complementary treatments such as the application of hydrogen peroxide or, in extreme cases, the total stop of water distribution. In addition to this, monitoring in reservoirs before water treatment plants and in effluents from waste stabilization ponds in WTPs is necessary to accurately quantify the potential impact of cyanotoxins on the environment.
URI:	http://www.repositorio.ufc.br/handle/riufc/58089
Aparece nas coleções:	DEHA - Teses defendidas na UFC

Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.