Caracterização das águas residuais do processo de tratamento na ETA de Tavira e optimização das condições operacionais e tecnológicas do Densadeg

• Autor(a) principal: Maié, David Filipe de Sousa
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/432
• topic: Teses; Qualidade da água; Estação de tratamento de água; Águas residuais; Reciclagem

Drinking water treatment plants (WTP) recycle water from residual streams, usually thickener`s sludges and filter backwash waters. This activity may reintroduce contaminants, which can impair treated water quality. An adequated operational control plan of water quality (OCPWQ) of the residual streams identifies which parameters are operation critical conditions, allowing the recicled water quality control. In this work the 2007 OCPWQ for Densadeg`s clarifier was analised. This equipment is responsable for treating Tavira`s WTP residual streams, under Águas do Algarve, S.A. management. It was observed that aluminum and dissolved organic carbon (DOC) were operational critical parameters, whose recycling created concentrations above law limits for treated water. Trihalomethanes (THM`s) formation potential was indicated by specific ultraviolet absorvance (SUVA) parameter. Bibliography pointed that microbiological parametres are the most critical for WTP`s residual water recycle. The OCPWQ`s analisys did not show the same results. Based on analised data, a new residual streams OCPWQ was proposed, which included thickener sludges and filter backwash waters. This new OCPWQ showed that pH and water alcalinity influenced aluminum concentration, which was again very high. This high aluminum concentration also induced high turbidity. It was concluded that these parameters are high related with each other, creating operation critical conditions. Filter backwash water analisys revealed THM`s formation, which can be a critical parameter under specific conditions. It was also concluded that microbiological parameters are not operation critical conditions. So, a most restricted control of pH, aluminum, water alcalinity, turbidity and DOC should be done, being these parameters that might be manipulated for operational conditions optimization of the Densadeg.