Influência da concentração de sólidos na transferência de oxigênio em reatores de lodo ativado

• Autor(a) principal: Araújo, Fernanda Jucá de Medeiros
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/40595
• topic: Respirometria; Concentração do lodo.; Constante de transferência de oxigênio; Respirometry; Oxygen transfer coefficient; Sludge concentration

One of the most important aspects to be controlled in operational costs for an activated sludge system is the concentration of dissolved oxygen (DO). Low concentrations of DO in aeration tanks directly affect the efficiency of substrate removal, jeopardizing the sludge’s mechanical and biological properties. On the other hand, high concentrations of DO cause considerable increases on the electrical energy costs to the sewage treatment plants. This research studies the influence of the sludge concentration (biomass) on the oxygen transfer capacity of the aerator. In this case, experimental laboratorial tests were performed in order to ascertain the oxygen transfer coefficient using the stationary method in presence of microorganisms, with the use of respirometry. An aerator was connected to the respirometer, which controlled the aeration and submitted different analyzed sludge concentrations to cycles of periods with and without aeration. Those had their starting and ending points controlled by specific software parameters. The results revealed that systems containing high sludge concentrations, of around 8 g/L, showed an electrical cost almost 2.6 times higher, in comparison to the same system using a sludge concentration of 2,6 g/L.