Author(s):
Madeira, Joana Cristina Cuco Pedrosa, 1986- 
Date: 2010
Persistent ID: http://hdl.handle.net/10451/2319
Origin: Repositório da Universidade de Lisboa
Subject(s): Poluição; Metais pesados; Qualidade da água; Aquíferos; Teses de mestrado - 2010
Description
Tese de mestrado. Biologia (Ecologia e Gestão ambiental). Universidade de Lisboa, Faculdade de Ciências, 2010 A eliminação de nitrato nas águas subterrâneas é prioritária em vários países, dada a sua toxicidade e presença generalizada. A biorremediação, por bioestimulação, consiste numa estratégia de remoção de nitrato frequentemente adoptada dada a sua acção rápida, baixo investimento e aplicação in-situ. Para além das vantagens referidas, aparenta ser a solução mais adequada do ponto de vista ambiental e prático. Neste estudo, a actividade microbiana é utilizada como principal factor de redução de nitrato a azoto molecular, através da estimulação do processo de desnitrificação biológica, após a adição de uma fonte de carbono à água subterrânea (etanol, serradura, carvão, ácido cítrico ou ácido acético). O local de estudo corresponde ao aquífero Serpa-Brinches, caracterizado como livre e pouco profundo, o que aumenta o seu risco de poluição. O principal objectivo deste trabalho consiste na elaboração de uma proposta de remediação do aquífero Serpa-Brinches, a partir da selecção da fonte de carbono mais eficiente na remoção de nitrato e com produção mínima de compostos tóxicos, bem como na identificação das bactérias desnitrificantes capazes de efectuar esta remoção de nitrato do aquífero. Pretendeu-se ainda simular o fluxo e movimento de partículas no aquífero, para identificar a técnica de aplicação in-situ mais adequada à estratégia de biorremediação desenvolvida neste estudo.
Nitrate is a pollutant with priority to be removed from groundwater, due to its toxicity and widespread presence. Bioremediation, trough biostimulation, is a nitrate removal strategy frequently adopted because it has a quick action, low investment requirement and on-site application. It also appears to be the most suitable solution from an environmental and practical perspective. In this study, the microbial activity is used as the main factor for reducing the nitrate to nitrogen gas, by stimulating the process of biological denitrification after the addition of a carbon source to a groundwater (ethanol, citric acid, acetic acid, sawdust or coal). The study site is the Serpa-Brinches aquifer, characterized as unconfined and shallow, what leads to a higher risk of pollution. The main goal of this work was the elaboration of a remediation proposal for the Serpa-Brinches aquifer, from the selection of the most efficient carbon source that provides a higher rate of nitrate reduction, with a minimal production of other toxic compounds and the identification of the autochthones denitrifying bacteria that can perform this nitrate removal. It was also pretended to simulate the aquifers flow and particle movement, to identify the on-site application most suited to the bioremediation strategy developed in this study. Nitrate is a pollutant with priority to be removed from groundwater, due to its toxicity and widespread presence.
Bioremediation, trough biostimulation, is a nitrate removal strategy frequently adopted because it has a quick action, low investment requirement and on-site application. It also appears to be the most suitable solution from an environmental and practical perspective.
In this study, the microbial activity is used as the main factor for reducing the nitrate to nitrogen gas, by stimulating the process of biological denitrification after the addition of a carbon source to a groundwater (ethanol, citric acid, acetic acid, sawdust or coal).
The study site is the Serpa-Brinches aquifer, characterized as unconfined and shallow, what leads to a higher risk of pollution.
The main goal of this work was the elaboration of a remediation proposal for the Serpa-Brinches aquifer, from the selection of the most efficient carbon source that provides a higher rate of nitrate reduction, with a minimal production of other toxic compounds and the identification of the autochthones denitrifying bacteria that can perform this nitrate removal. It was also pretended to simulate the aquifers flow and particle movement, to identify the on-site application most suited to the bioremediation strategy developed in this study.
Document Type
Master Thesis
Language
Portuguese
Advisor(s)
Carvalho, Maria do Rosário da Encarnação de, 1963-; Chaves, Sandra Isabel Mourinha Lopes, 1974-
