Biological removal of ammoniacal nitrogen from high salinity wastewater

A presente tese teve como objetivo analisar os efeitos do sal na remoção de amônia e na diversidade da comunidade microbiana envolvida neste processo. O trabalho foi dividido em três etapas, descritas em três artigos técnico-científicos. O primeiro artigo abordou os efeitos da salinidade na remoção de amônia de águas de produção de petróleo, em reatores em batelada sequencial. Foram realizados ensaios de bancada com a construção de reatores biológicos com alimentação intermitente. Utilizou-se lodo e efluentes industriais provenientes de uma estação de tratamento de efluentes de um terminal de petróleo. Os experimentos mostraram que se pode alcançar uma remoção completa de amônia via nitrificação biológica a concentrações de sal de até 100 g NaCl L^-1. No entanto, a uma concentração de 125 g NaCl L^-1, os microrganismos nitrificantes foram inibidos e uma remoção muito baixa de amônia foi observada nessas condições. No segundo artigo avaliaram-se as mudanças do perfil da comunidade microbiana do lodo responsável pela remoção de amônia da água de formação de petróleo quando submetidas ao aumento gradual de sal (NaCl) na etapa anterior. Analisou-se amostras de lodo de dois reatores biológicos em batelada sequencial, que foram operados com adição semanal de 5 g L^-1 de NaCl, até a completa inibição do processo de remoção de amônia que ocorreu com uma concentração de 125 g L^-1. Durante o processo de aclimatação do lodo ao sal, as amostras foram coletadas e tiveram seu DNA extraído. Realizou-se o PCR-DGGE e o sequenciamento massivo do gene rRNA 16S para análise da diversidade microbiana. Os perfis de bandas do PCR-DGGE mostraram que ocorreu uma mudança na comunidade microbiana à medida que se aumentou a concentração de sal no reator. Observou-se uma redução da presença de bactérias e concomitantemente um aumento das populações de archaeas. Os dados do sequenciamento revelaram que a remoção de amônia no reator é realizada por diferentes vias, através de bactérias nitrificantes autotróficas (Nitrosococcus, Nitrosomonas, Nitrosovibrio, Nitrospira e Nitrococcus), Archaea oxidante de amônia (Candidatus nitrosoarchaeum), microrganismos ANAMMOX (Candidatus Brocardia, Candidatus Kuenenia e Candidatus Scalindua) e potenciais nitrificantes heterotróficos (Paracoccus spp., Pseudomonas spp., Bacillus spp., Marinobacter sp., e Alcaligenes spp.). O terceiro trabalho investigou os efeitos do aumento gradual da concentração de NaCl na eficiência de remoção de amônia e na estrutura e diversidade da comunidade microbiana do grânulo aeróbio. Para tal, dois reatores biológico em batelada sequencial foram operados visando a formação de lodo granular aeróbio. Os reatores foram alimentados com efluente sintético, o qual foi enriquecido com NaCl, cuja concentração foi aumentada 5 g L^-1 de NaCl por semana. A remoção de amônia se manteve eficiente até salinidade de 40 g L^-1, sendo observado um leve decréscimo da eficiência com o aumento da salinidade. Não houve acumulo de nitrito e nitrato no efluente tratado, a remoção de ambos aumentou com o acréscimo de NaCl. Tais resultados evidenciaram a ocorrência de nitrificação/desnitrificação simultânea. Com o aumento da concentração de sal nos reatores os grânulos diminuíram de tamanho até se desintegrarem. A granulação aeróbia foi desfavorecida em concentração de NaCl acima de 10 g L^-1. A abundância de bactéria e archaea aumentou com o acréscimo de NaCl. Diversos gêneros de microrganismos responsáveis pela remoção de nitrogênio foram identificados no sequenciamento, incluindo aqueles envolvidos nos processos de nitrificação e desnitrificação convencionais (Nitrosomonas, Nitrosovibrio, Nitrospira, Nitrobacter, Denitromonas, Paracoccus, Bacillus, Klebsiella, Pseudomonas, Nitratireductor, Achromobacter, Thiobacillus, Azoarcus, Thauera, Alcaligenes, Hyphomicrobium, Rhodopseudomonas e Micrococcus), os microrganismos ANAMMOX (Candidatus kuenenia) e os heterotróficos (Paracoccus sp., Bacillus sp., Pseudomonas sp., Acinetobacter sp., Alcaligenes sp. e Aeromonas sp.).This thesis aimed to analyze the effects of salt removal of ammonia and the diversity of the microbial community involved in this process. The work was divided into three chapters presented with three technical-scientific articles. The first article discusses the effects of salinity on the removal of ammonia from produced water from oil and gas production in sequencial batch reactors. Lab-scale tests were carried out in three sequencing batch biological reactors. The wastewater and sludge used in study consisted of produced water from oil extraction collected at an industrial treatment plant from a Brazilian petroleum terminal. The experiments showed that complete of ammonia removal via biological nitrification was achieved at salt concentrations up to 100 g NaCl L^-1. However, at a concentration 125 g NaCl L^-1, the nitrifying microorganisms were inhibited and a very low ammonia removal was achieved under these conditions. In the second article it was evaluated the changes of the microbial community profile of sludge responsible for the ammonia removal from produced water when subjected to a gradual increase of salt (NaCl). The biological sludge samples from two sequential batch reactors which were operated with a weekly addition of 5 g L^-1 NaCl were analyzed, until the complete inhibition of the ammonia removal process, which occurred at a concentration of 125 g L^-1. During the sludge acclimation process, the samples were collected and had their DNA extracted. The PCR-DGGE and massive sequencing of 16S rRNA region were carried out for analysis of microbial diversity. The profiles bands of PCR-DGGE showed that there was a change in the microbial community as the increased salt concentration in the reactor. It was observed a reduction in the bacteria population while the population of archaeas had an increase. The data of the 16S rRNA gene sequencing revealed that the ammonia removal was performed in different routes. The main microorganisms observed were the conventional autotrophic nitrifying bacteria (Nitrosococcus, Nitrosomonas, Nitrosovibrio, Nitrospira, Nitrococcus), archaea oxidizing ammonia (Candidatus nitrosoarchaeum), ANAMMOX (Candidatus Brocardia, Candidatus Kuenenia, Candidatus Scalindua), and potential heterotrophic nitrifyers (Paracoccus spp., Pseudomonas spp., Bacillus spp., Marinobacter sp., Alcaligenes spp.). The third paper investigated the effects of gradual increase of NaCl concentration in the ammonia removal efficiency and the microbial structure and diversity of aerobic granular sludge. Two biological sequencing batch reactors were operated with aerobic granular sludge. The reactors were fed with a synthetic effluent enriched gradually with NaCl (5 g L^-1 of NaCl per week). The removal of ammonia remained effective within all salinities tested, but had a slight efficiency decline when salinity increased. There was no accumulation of nitrite and nitrate in the treated effluent. The nitrite and nitrate removal increased with the addition of NaCl. These results proved the occurrence of simultaneous nitrification/denitrification. As the salt concentration increased in the reactor, the aerobic granules size diminished until they completely disintegrated. The aerobic granulation was negatively affected in NaCl concentration above 10g L^-1. The abundance of bacteria and archaea increased with NaCl addition. Several genera of microorganisms responsible for removing ammonia were identified, including the conventional nitrification/denitrification (Nitrosomonas, Nitrosovibrio, Nitrospira, Nitrobacter, Denitromonas, Paracoccus, Bacillus, Klebsiella, Pseudomonas, Nitratireductor, Achromobacter, Thiobacillus, Azoarcus, Thauera, Alcaligenes, Hyphomicrobium, Rhodopseudomonas and Micrococcus), ANAMMOX (Candidatus kuenenia) and heterotrophic/aerobic nitrification denitrification microorganisms (Paracoccus sp., Bacillus sp., Pseudomonas sp., Acinetobacter sp., Alcaligenes sp. and Aeromonas sp.).Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Avaliação do emprego da radiação ultravioleta na desinfecção de esgoto sanitário

A presente pesquisa teve como objetivo avaliar a potencialidade do uso da radiação ultravioleta (UV) como agente desinfetante de esgoto sanitário proveniente do tratamento biológico contendo concentrações de sólidos suspensos totais que variaram de 30 a 75 mg/L. Os ensaios de desinfecção foram realizados em um reator em escala de bancada de laboratório e a efetividade do processo foi avaliada empregando os microrganismos indicadores Coliformes Totais (CT) e Escherichia coli. Embora a baixa qualidade do efluente, no que se refere à presença de sólidos e turbidez, tenha limitado a eficiência do processo, os resultados da inativação de CT e E. coli variaram de valores menores que 1 log até 5 log de inativação com doses de radiação UV empregadas que variaram de 10,54 a 317,1 mWs.cm-2, permitindo concluir sobre a viabilidade do uso desta tecnologia para desinfecção de efluentes secundários

Evaluation of the use of ultraviolet radiation to disinfect sewage

agent of sewage coming from biological treatment having concentration of total suspended solids that varies from 30 to 75 mg/L. The disinfection tests were performed in a reactor in scale of laboratory work surface and the process effectiveness was evaluated applying total coliforms indicator microorganisms (TC) and Escherichia coli. Although the low quality of the effluent, as far as the presence of solids and turbidity is concerned has limited the process efficiency, the results of inactivation of TC and E.coli varied of values smaller than 1 log to 5 log of inactivation with dosages of UV applied radiation that varied from 10,54 to 317,1 mWs.cm-2, allowing to conclude about the feasibility to use this technology to disinfect the secondary effluents

Nutrient and pathogen removal from anaerobically treated black water by microalgae

The demand for systems that efficiently and sustainably recover value-added compounds and materials from waste streams is a major challenge. The use of wastewater as a source for recovery of carbon and nutrients is an attractive and sustainable alternative. In this study, anaerobically treated black water was treated in photobioreactors (PBRs) inoculated with Chlorella sorokiniana, and the process was investigated in terms of phosphorus and nitrogen removal, biomass growth, and the removal of pathogens. The consumption of bicarbonate (alkalinity) and acetate (volatile fatty acids) as carbon sources by microalgae was investigated. The average nutrient removal achieved was 66% for N and 74% for P. A high consumption of alkalinity (83%) and volatile organic acids (76%) was observed, which suggests that these compounds were used as a source of carbon. The biomass production was 73 mg L−1 day−1, with a mean biomass of 0.7 g L−1 at the end of the batch treatment. At the end of the experiments, a log removal/inactivation of 0.51 log for total coliforms and 2.73 log for Escherichia coli (E. coli) was observed. The configuration used, a flat-panel PBR operated in batch mode without CO2 supplementation, is a cost-effective and environmentally sustainable method for recovering of nutrients and production of algal biomass

Ammonium Removal From High-salinity Oilfield-produced Water: Assessing The Microbial Community Dynamics At Increasing Salt Concentrations

Water generated during oil exploration is chemically complex and contains high concentrations of ammonium and, in some cases, high salinity. The most common way to remove ammonium from effluent is a biological process, which can be performed by different routes and different groups of microorganisms. However, the presence of salts in the effluents could be an inhibiting factor for biological processes, interfering directly with treatment. This study aimed to evaluate changes in the profile of a microbial community involved in the process of ammonium removal when subjected to a gradual increase of salt (NaCl), in which the complete inhibition of the ammonium removal process occurred at 125 g L-1 NaCl. During the sludge acclimatization process, samples were collected and submitted to denaturing gradient gel electrophoresis (DGGE) and massive sequencing of the 16S ribosomal RNA (rRNA) genes. As the salt concentration increased in the reactor, a change in the microbial community was observed by the DGGE band profiles. As a result, there was a reduction in the presence of bacterial populations, and an increase in archaeal populations was found. The sequencing data suggested that ammonium removal in the reactor was carried out by different metabolic routes by autotrophic nitrifying bacteria, such as Nitrosococcus, Nitrosomonas, Nitrosovibrio, Nitrospira, and Nitrococcus; ammonium-oxidizing archaea Candidatus nitrosoarchaeum; ANAMMOX microorganisms, such as Candidatus brocadia, Candidatus kuenenia, and Candidatus scalindua; and microorganisms with the potential to be heterotrophic nitrifying, such as Paracoccus spp., Pseudomonas spp., Bacillus spp., Marinobacter sp., and Alcaligenes spp.1012859870PETROBRAS [8603-4600391375

Ammonium removal from high-salinity oilfield-produced water: assessing the microbial community dynamics at increasing salt concentrations

Water generated during oil exploration is chemically complex and contains high concentrations of ammonium and, in some cases, high salinity. The most common way to remove ammonium from effluent is a biological process, which can be performed by different routes and different groups of microorganisms. However, the presence of salts in the effluents could be an inhibiting factor for biological processes, interfering directly with treatment. This study aimed to evaluate changes in the profile of a microbial community involved in the process of ammonium removal when subjected to a gradual increase of salt (NaCl), in which the complete inhibition of the ammonium removal process occurred at 125 g L−1 NaCl. During the sludge acclimatization process, samples were collected and submitted to denaturing gradient gel electrophoresis (DGGE) and massive sequencing of the 16S ribosomal RNA (rRNA) genes. As the salt concentration increased in the reactor, a change in the microbial community was observed by the DGGE band profiles. As a result, there was a reduction in the presence of bacterial populations, and an increase in archaeal populations was found. The sequencing data suggested that ammonium removal in the reactor was carried out by different metabolic routes by autotrophic nitrifying bacteria, such as Nitrosococcus, Nitrosomonas, Nitrosovibrio, Nitrospira, and Nitrococcus; ammonium-oxidizing archaea Candidatus nitrosoarchaeum; ANAMMOX microorganisms, such as Candidatus brocadia, Candidatus kuenenia, and Candidatus scalindua; and microorganisms with the potential to be heterotrophic nitrifying, such as Paracoccus spp., Pseudomonas spp., Bacillus spp., Marinobacter sp., and Alcaligenes spp