Dispersão de bioaerossóis por aeradores em uma estação de tratamento de esgoto sanitário

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tratamento de esgoto sanitário utilizando reatores anaeróbios operados em bateladas sequenciais (escala piloto)

The performances of two anaerobic sequencing batch reactors (1.2 m 3) containing biomass immobilized in inert support and as granular sludge in the treatment of domestic sewage from the Campus of São Carlos-University of São Paulo were evaluated. The experimental phase lasted seventy days. During this period, the reactors presented quite similar performances in respect to COD and total suspended solids removal, achieving average efficiencies of approximately 60% and 75%, respectively. The analysis using molecular biology techniques on biomass samples taken at 35 th and 70 th showed differences in the bacterial community in the reactors indicating that the type of biomass immobilization selected the populations differently. A higher similarity was found for the Archaea domain probably because these microorganisms utilize specific substrates formed at the end of the anaerobic process.

Efeito da redução do diâmetro interno sobre o desempenho de um reator aeróbio de leito fluidizado no tratamento de esgoto sanitário

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da auto-suficiência energética de reatores anaeróbios no tratamento de esgoto sanitário e água cinza

The anaerobic treatment of sewage is widely employed in Brazil and it is an appreciated way for the treatment of effluents, helping to reduce the environmental impact in rivers. The methane gas obtained from the process can be applied to improve the energetic efficiency of the system, reducing the amount of waste and the cost of the treatment process. This work presents the net energy balance of anaerobic reactors applied to the treatment of sewage. The analysis was performed considering full-scale and laboratory-scale treatment systems. In laboratory scale, the results from three kinds of systems were compared regarding the biological treatment of greywater. Two of them (UASB7 and UASB12) were anaerobic and the other one was a combined anaerobic-aerobic system (UASB7/SBR6). Greywater methanization (compared to theoretical maximum) was calculated considering 100% removal (g BOD/day), the literature percentage removal and the anionic surfactant presence in the effluentt. For each of these three cases, the efficiencies were, respectively, 16.9%, 43.6% and 51.3% in UASB7 reactor, 25.6%, 50.3% and 59.2% in UASB12 reactor and 30.6%, 61.2% and 71.9% in UASB7/SBR6 reactor. The energetic potential was found to be 4.66x10-4, 7.77x10-4 and 5.12x10-4 kWh/L for the UASB7, UASB12 and UASB7/SBR6 reactors, respectively. The pumping system, the aeration (in the anaerobic-aerobic system) and the temperature controlled heating system were considered to calculate the energetic consumption. However, the third one was not employed since tropical regions like Brazil do not need heating systems and also because of its high energetic consumption. The calculated net energy balance in the reactors was negative in the case of greywater, respectively -0.16, -0.28 and -0.18 kWh/L for the reactors UASB7, UASB12 and UASB7/SRB6. In full scale (ETE Jardim das Flores - Rio Claro, SP), the average energy... (Complete abstract click electronic access below)

Estudo sobre a condição de coleta e tratamento de esgoto sanitário do município de Ubatuba-SP

The actual work broaches a study about the collection and treatment of sanitary sewage from the municipality of Ubatuba in its operational aspects and the tariff policy from the service. Themes related to the subject like the history of collection and treatment of sewage, its development in Brazil and its importance for public health and environmental preservation, as well as historical and geographical aspects of Ubatuba/SP, are present in the literature review. The methodology consists in guided visit in the colletion and treatment of sewage facilities and interview with technical managers. With the technical data obtained, it is made a discussion of the results and possible recommendations

Avaliação da auto-suficiência energética de reatores anaeróbios no tratamento de esgoto sanitário e de água preta

The purpose of this project is to verify whether anaerobic reactors applied to sewage treatment are energetically self-sufficient. This evaluation can be made by balancing the methane produced through the anaerobic transformation stages (hydrolysis, acidogenesis, acetogenesis and methanogenesis) and the reactor energy consumption requirements. The original project included methanogenic activity tests, which could not be performed due to setbacks in the installation of an analytical instrument. Scientific articles about bench- and full-scale anaerobic reactors were investigated instead. An average substrate-to-methane conversion efficiency of 58,2±18,6% was found for the bench-scale reactors and higher efficiencies (89,2%) were found for the cases which had higher Organic Loading Rates (OLRs) values. The average energy output was 0,013 kWh/Lsewage, value unable to meet the energy needs for the reactor operation, considering equipments normally used such as temperature controller. This balance can become positive if few hypotheses are made, for example (i) to eliminate the use of temperature controller (ii) to alter the operation pattern from continuous to intermittent. Based on energy balance assessment of eight bench-scale reactors, it was observed that the implementation of a system for biogas utilization is not energetically feasible. However, interesting results were found for a full-scale sewage treatment plant, ETE Ouro Verde – Foz do Iguaçu, PR, Brazil. Even though its substrate-tomethane conversion efficiency was about 10% only, the energy balance was quite positive, with energy consumption of 68 kWh/month and energy production of 660 kWh/month. This analysis leads us to conclude that energy recovery from full-scale sewage treatment plants should be practiced by other plants

Nova configuração de um reator compartimentado anaeróbio/aeróbio para o tratamento de esgoto sanitário de baixa carga

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação comparativa entre custos dos processos MBBR/IFAS e lodo ativado para o tratamento de esgoto sanitário

O processo MBBR/IFAS, Moving Bed Biofilm Reactor/Integrated Fixed Film Activated Sludge, é uma tecnologia recente para o tratamento de esgoto que incorpora tanto biomassa em suspensão como aderida. Seus parâmetros de controle são os mesmos aplicados ao processo de lodo ativado, observadas algumas especificidades. Como objetivo principal deste trabalho, apresenta-se uma análise comparativa entre os custos de implantação de uma unidade IFAS e de lodo ativado operando sob alta taxa, na faixa convencional e com aeração prolongada, para populações de 50.000 e 500.000 habitantes. Os resultados mostraram que, sob as hipóteses assumidas para a implantação dos reatores, o custo do processo de lodo ativado foi de 36% até 100% do custo do processo IFAS, dependendo da carga orgânica aplicada, do preço do terreno ou do custo do meio suporte.

Tratamento de esgoto sanitário em reator anaeróbio horizontal de leito fixo (RAHLF): escala piloto

Este trabalho apresenta as avaliações de desempenho, das demandas operacionais e dos fatores intervenientes no aumento da escala da unidade piloto do Reator anaeróbio Horizontal de Leito Fixo (RAHLF) no tratamento de esgoto sanitário após passagem por peneira com malha de 1 mm, durante dois anos de operação. O reator dispunha de volume total de 237,5 1, construídos com tubos comerciais de PVC de 14,5 cm de diâmetro (D), dispostos em cinco módulos horizontais em série de 2,88 m, perfazendo um comprimento total de (L) de 14,4 m e relação de total de L/D de 100. O suporte de imobilização de biomassa, espuma de poliuretano em matrizes cúbicas de 1 cm de aresta, mostrou-se adequado ao desenvolvimento do biofilme. Em partida, sem inoculação prévia, ocorreu a sua consolidação a partir de 70 dias, com predominância de morfologia semelhante a Methanosaeta sp. em relação a da Methanosarcina. Em torno de 90 dias com afluente de 350 mg/l de DQO, observe-se a melhor qualidade do efluente, com valor de 100 mg/l de DQO. Em longa operação ocorreu queda de rendimento e menor reprodutibilidade das previsões do projeto, atribuída aos constantes entupimentos e ineficácia das operações de limpeza, com o comprometimento de volume reacional verificados por estudos de hidrodinâmica. Da investigação das origens dos equipamentos observou-se tratar mais de um efeito local e qualitativamente relacionado à biomassa retida que propriamente quantitativo e extensivo ao longo de todo reator, com produção continuada de polímeros extracelulares, promovendo um efeito sinérgico com os predominantes organismos filamentosos e com os sólidos particulados retidos no leito. Diante das potencialidades desta configuração de reator apontam-se alternativas de mitigação dos entupimentos e o direcionamento dos estudos necessários para novo aumento de escala para o tratamento de esgoto sanitário.

Ocorrência e remoção dos protozoários patogênicos Giardia spp. e Cryptosporidium spp. em sistemas de tratamento de esgoto sanitário

O propósito do presente estudo foi investigar e monitorar a remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. por diferentes processos de uma estação de tratamento de esgoto (ETE) em escala plena, composta basicamente por tratamento preliminar, reator UASB e flotador por ar dissolvido, e verificar a ocorrência desses protozoários no lodo do reator UASB e do flotador. Além disso, avaliou-se a remoção desses parasitos pelo processo de flotação por ar dissolvido em escala de bancada (equipamento Flotateste). Analisou-se a qualidade das amostras a partir de variáveis físicas e químicas, e pela detecção de microrganismos indicadores - E. coli, coliformes totais e Clostridium perfringens. Os métodos de detecção de protozoários se basearam nas etapas de concentração (tripla centrifugação ou filtração em membrana seguida de tripla centrifugação); purificação por separação imunomagnética (IMS); detecção por reação de imunofluorescência direta (RID). As recuperações de cistos variaram de 32,6 a 67,0 % dependendo do método adotado, já para os oocistos as recuperações estiveram na faixa de 5,6 a 12,0 %. Na ETE-Monjolinho foram detectadas significativas quantidades de cistos de Giardia spp. em 100% das amostras de esgoto analisadas, com concentração média de 1,89 x 104 e 2,35 x 102 cistos.L-1 no esgoto bruto e tratado, respectivamente. Já os oocistos de Cryptosporidium spp. foram detectados em 39,0 % das amostras de esgoto, com concentração média de 1,35 x 102 oocistos.L-1 no esgoto bruto e 5,87 oocistos.L-1 em esgoto tratado (após flotador). A remoção global da ETE para remoção de Giardia spp. foi em média 2,03 log. O lodo do reator UASB e lodo do flotador apresentaram altas quantidade de (oo)cistos, constatando-se a tendência desses sistemas em concentrar os (oo)cistos por seus processos físicos. Algumas correlações significativas foram encontradas, como correlação entre a concentração de cistos no lodo e a variável sólidos totais, a concentração de cistos no esgoto bruto e as variáveis cor aparente, DQO total e particulada, e a concentração de cistos no efluente UASB e o microrganismo Clostridium perfringens. Diferentemente do flotador em escala plena, o processo do flotação por ar dissolvido em escala de bancada alcançou elevadas remoções médias de cistos de Giardia spp., entre 2,5 e 2,7 log nas diferentes condições de floculação estudadas.

Reator de leito estruturado com recirculação submetido à aeração intermitente no tratamento de esgoto sanitário

The release of nitrogen compounds in water bodies can result in many environmental problems, so treat wastewater, such as sewage in order to remove not only organic matter but also nitrogen has been studied a few decades. From the above, the objective of this study was to evaluate the performance of a structured bed reactor, continuous flow, with recirculation, in removing organic matter and nitrogen present in wastewater under different cycles of intermittent aeration (AI) and to evaluate the influence of these cycles in the development of nitrifying bacteria (Oxidizing Bacteria Ammonia - BOA and Bacteria Oxidizing Nitrite - BON) and denitrifying (DESN) adhered (Support Material - MS) and suspension (Effluent - EF and sludge - LD). The reactor used has usable volume of 9.4 L. As support materials (MS) polyurethane foam was used, cut and fixed in PVC rods. 3 were worked aeration phases (AE) and non-aeration (AN) at different stage: Stage 1 (4 h EA / AN 2H); Stage 2 (2H EA / AN 1 h) and Phase 3 (2H EA / AN 2 h). During all hydraulic detention time phases was kept at 16 h and the effluent recirculated at a rate of 3 times the inflow. Were analyzed: pH, total alkalinity, temperature, chemical oxygen demand (COD), Biochemical Oxygen Demand (BOD), nitrogen Kjeldhl Total (NKT), ammonia-N-N-NH4+, nitrito-N-NO2+andnitrato-NO3-. The concentration of BOA, BON and DESN was determined using the number More Provável.gSSV-1 (NMP.gSSV-1). In phase 1 the percentage removal NTK N-NH4+ and NT was 76±10%, 70±21% and 67±10% respectively. In Phase 2 80±15% of removel NKT, 86±15% of N-NH4+ e 68±9% of removel NT e na Fase 3 de 58±20%, 72±28% and 41±6% of NKT, N-NH4+ of NT, respectively. The denitrification efficiency in stage 3 was over 70%, indicating that occurred in the reactor the process of simultaneous nitrification and denitrification (NDS). DQOT the removal percentages were 88 ± 4% in Phase 1, 94 ± 7 in Phase 2 and 90± 11% in Phase 3. The multivariate ANOVA applied to NMP.gSSV-1, it indicated that there was significant (F: 20,2, p <0,01) between the analyzed concentration of organisms AI in different cycles, but the differences between NMP.gSSV-1 depends not only isolated factors but of which means, and phase groups being analysis. From the results it is concluded that the working system is efficient in terms of nitrogen removal and organic matter, and that the stage with the highest availability of Dissolved Oxygen (DO) and C/N ratio (Step 2), was the one obtained the lower concentrations of organic matter effluents and N-NH4+. Hinted that there was a significant difference between the concentration (NMP.100mL-1) of the analyzed organizations (BOA, BON and DESN), but this difference does not depend on factors alone but of which means (MS, EF or LD), stages (1, 2 or 3) and groups (BOA, BON and DESN) is being considered.

Estudo da lixiviação bacteriana de metais presentes em lodo de esgoto sanitário

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Proposta metodológica para a correção do coeficiente de retorno de esgoto sanitário em unidades com sistemas de aproveitamento de água pluvial

The use of rainwater for non-potable purposes generates a reduction in the consumption of treated water, however, this reduction is not observed in the generation of wastewater, as this is independent of the water source. In Brazil, the pricing on the services of collection and treatment of sewage, in general, is based on the coefficient of return of the sewage disposal system, which has a relation sewer / water proportional to the consumption of treated water measured at the consumer unit. The use of rainwater originating from utilization systems infer on the coefficient, underestimating the volume of wastewater generated. Therefore, this study presents a methodology for setting the coefficient of return. Different roof areas, reservoir volumes and rates of water consumption situations were simulated. The behavior of adjustment of the coefficient of return were also analyzed for the average area per capita roof (m² / inhabitant) of Rio Claro - SP. As a result, it can be seen that the adjustment of the coefficient of return is directly proportional to the increase of the roof areas and the volumes of reservoirs, and inversely proportional to the total water demand. The corrected coefficient of return showed the minimum value of 0.83 and a maximum value of 1.45, this variation corresponds to the maximum ratio between the demands of total water and rainwater, since the exploitation of rain water should be used only for non-potable uses, according to NBR 15527 / 07. To the municipality of Rio Claro - SP was noted an adjustment of the coefficient of return ranging from 0.99 to 6.61

Estimativa da correção do coeficiente de retorno de esgoto sanitário em habitações com sistemas de aproveitamento de água pluvial: estudo de caso da cidade de Bauru (SP)

Pós-graduação em Engenharia Civil e Ambiental - FEB