The microbial community structure of the biomass selected in two distinctly inoculated anaerobic oxidation of ammonium (anammox) reactors was investigated and compared with the help of data obtained from 454-pyrosequencing analyses. The anammox reactors were operated for 550 days and seeded with different sludges: sediment from a constructed wetland (reactor I) and biomass from an aerated lagoon part of the oil-refinery wastewater treatment plant (reactor II). The anammox diversity in the inocula was evaluated by 16S rRNA gene-cloning analysis. The diversity of anammox bacteria was greater in the sludge from the oil-refinery (three of the five known genera of anammox were detected) than in the wetland sludge, in which only Candidatus Brocadia was observed. Pyrosequencing analysis demonstrated that the community enriched in both reactors had differing compositions despite the nearly similar operational conditions applied. The dominant phyla detected in both reactors were Proteobacteria, Chloroflexi, Planctomycetes, and Acidobacteria. The phylum Bacteroidetes, which is frequently observed in anammox reactors, was not detected. However, Acidobacteria and GN04 phyla were observed for the first time, suggesting their importance for this process. Our results suggest that, under similar operational conditions, anammox populations (Ca. Brocadia sinica and Ca. Brocadia sp. 40) were selected in both reactors despite the differences between the two initial inocula. Taken together, these results indicated that the type of inoculum and the culture conditions are key determinants of the general microbial composition of the biomass produced in the reactors. Operational conditions alone might play an important role in anammox selection.

Overview of sewage treatment in the South, Southeast and Midwest regions of Brazil: most employed technologies Resumo Em vista dos compromissos assumidos pelo Brasil para o incremento dos níveis de tratamento de esgoto sanitário, faz-se importante uma leitura sobre as tecnologias mais aplicadas nos cenários regionais. O objetivo deste artigo é reportar o atual estágio de emprego dos diferentes processos associados ao tratamento de esgoto sanitário em seis estados brasileiros das regiões Sul, Sudeste e Centro-Oeste, concomitantemente com o Distrito Federal, com ênfase em suas aplicações para diferentes escalas de população atendida. Os dados utilizados foram coletados junto aos prestadores de serviço de saneamento estaduais e municipais, sendo posteriormente confrontados com uma base de dados cedida pela Agência Nacional de Águas. Ao todo, inventariaram-se 1.667 estações de tratamento de esgoto (ETEs), que têm capacidade instalada de atendimento a aproximadamente 75% da população urbana de toda a região contemplada no estudo. As tecnologias de tratamento de esgoto sanitário mais empregadas são: reatores UASB, lagoas de estabilização e lodos ativados. Conjuntamente, essas três tipologias de tratamento totalizam 90% das ETEs implantadas, sendo responsáveis por 81% da capacidade instalada de tratamento. Palavras-chave: Estação de tratamento de esgoto (ETE). Reator UASB. Lagoas de estabilização. Lodos ativados.

This paper aims to present perspectives for energy (thermal and electric) and nutrient (N and S) recovery in domestic sewage treatment systems comprised of upflow anaerobic sludge blanket (UASB) reactors followed by sponge-bed trickling filters (SBTF) in developing countries. The resource recovery potential was characterized, taking into account 114 countries and a corresponding population of 968.9 million inhabitants living in the tropical world, which were grouped into three desired ranges in terms of cities' size. For each of these clusters, a technological arrangement flow-sheet was proposed, depending on their technical and economic viability from our best experience. Considering the population living in cities over 100, 000 inhabitants, the potential of energy and nutrient recovery via the sewage treatment scheme would be sufficient to generate electricity for approximately 3.2 million residents, as well as thermal energy for drying purposes that could result in a 24% volume reduction of sludge to be transported and disposed of in landfills. The results show that UASB/SBTF systems can play a very important role in the sanitation and environmental sector towards more sustainable sewage treatment plants.