No abstract

The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside biofilms. Other techniques of molecular biology, such as fluorescence in situ hybridization (FISH), have also contributed to this matter because their application aids in the identification of the bacterial populations that compose the biofilms. The focus of this paper was to study the loading rate and surface velocity to promote the development of nitrifying biofilms in three distinct flow cells that were employed in the post treatment of a synthetic wastewater simulating the effluent from a UASB (Upflow Anaerobic Sludge Blanket) reactor. Using the FISH technique, it was found that the population of ammonia-oxidizing-bacteria was greater than that of nitrite-oxidizing-bacteria; this was also supported by the lower production of nitrate determined by physicochemical and microsensor analyses. It was verified that the loading rate and surface velocity that promoted the greatest nitrogen removal were 0.25 g N-amon m(-2)biofilm day(-1) and 1 m h(-1), respectively.

The dissolved oxygen microsensor allowed the measurement of the amount of dissolved oxygen in the biofilm, which is indicative of the intensity of the microbial metabolic activity (viability), correlating the results with biofilm thickness. The DOMS was effective in freshly extracted roots, but had limitations in roots contaminated in vitro after short periods (7 and 21 days) of contamination.

Um sistema de tratamento de água apto para utilização em comunidades isoladas é o filtro lento domiciliar. Este trabalho comparou a eficiência de um filtro lento domiciliar com meios filtrantes oriundos de resíduos da (FLD reciclado), com um filtro lento domiciliar convencional, avaliando características físico-químicas e microbiológicas da água filtrada, segundo critérios estabelecidos pela Portaria do Ministério da Saúde nº 5/2017 que consolidou a Portaria nº 2914/2011 sobre procedimentos de controle e vigilância da qualidade da água para consumo humano e seu padrão de potabilidade. Os resultados sinalizam que o FLD reciclado pode atender todos os parâmetros analisados, destacando-se a turbidez e os coliformes totais. Sugere-se, portanto, a realização de estudos para determinação do tempo de maturação e da redução do tempo de repouso necessário para que a água filtrada esteja apta para o consumo, tendo em vista a promoção do FLD reciclado como alternativa atrativa em localidades com baixo adensamento populacional.

GONZALEZ, B.C. Generation of electric energy from electrodes immersed in system named of biofuel cell consisted of an anaerobic and an aerobic reactor operated in series fed with wastewater. 2013. 187f. Tese (Doutorado)