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Digestão anaeróbia de vinhaça em reatores UASB termofílicos, em série, com adição de Fe, Ni e Co /Araujo, Daniele Medeiros de. January 2017 (has links)
Orientador: Roberto Alves de Oliveira / Coorientador: Rose Maria Duda / Banca: Valderi Duarte Leite / Banca: Marcelo Bruno / Resumo: Neste trabalho avaliou-se os efeitos da suplementação de ferro, níquel e cobalto na produção de metano da vinhaça proveniente da destilação do etanol de cana-de-açúcar, em reatores anaeróbios de fluxo ascendente com manta de lodo (UASB, R1 e R2) termofílicos, em série. Para determinar os efeitos da adição do Fe, Ni e Co, o experimento foi realizado em 3 diferentes fases. Na fase I foi realizada a partida dos reatores UASB, R1 e R2, com o aumento gradativo da carga orgânica volumétrica (COV) até valores de 9,4 g DQOtotal (L d)-1. Nas fases II e III a COV variou entre 9,9 a 14,9 g DQOtotal (L d)-1, e a fase III distinguiu-se da fase II pela suplementação com Fe, Ni e Co, na vinhaça afluente. Para o R1, a suplementação com elementos traço induziu ao decréscimo de ácidos voláteis totais, de 1801 para 834 mg L-1, aumento na produção volumétrica de metano (PVM) em 101% e aumento na eficiência remoção de DQO para 53%. O Fe foi considerado o principal elemento traço por seus efeitos de precipitação com sulfeto e participação nas fases acetogênicas e metanogênicas da digestão anaeróbia. As relações Fe/DQO, Ni/DQO e Co/DQO de 12,59, 0,138 e 0,191 mg (g DQOremovida)-1, respectivamente, foram consideradas ideais para o R1, pois, possibilitaram as mais altas PVM atingindo até 1,4 L CH4 (L d)-1. No sistema (R1+R2), a adição de Fe, Ni e Co promoveu estabilidade operacional, e auxiliou na remoção de DQO, melhorando a eficiência total do sistema. Porém, não favoreceu a PVM, que manteve-se com... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this study was evaluated the effects of supplementation with iron, nickel and cobalt on vinasse in reactors upflow anaerobic sludge blanket (UASB, R1 and R2) thermophilic, in series. To determine the effects of the addition of trace elements, the experiment was conducted in 3 phases. During the first phase was characterized by the gradual increase of the organic loading rate (OLR) up to 9.4 g CODtotal (L d)-1, and start-up of system. In the phase II and III the OLR varied between 9.9 to 14.9 g CODtotal (L d)-1, the phase III distinguished of phase II only in trace element supplementation. For R1, trace element supplementation induced a decreased in total volatile acids, from 1801 to 834 mg L-1, increase in methane production rate (MPR) by 101% and increased in chemical oxygen demand (COD) removal efficiency to 53%. The Fe was considered the most relevant in the system due to its ability to precipitate with sulfide and participation in acetogenic and methanogenic phases of anaerobic digestion. The ratios Fe/COD, Ni/COD and Co/COD 12.59, 0.138, 0.191 mg g-1 CODremoved, respectively, they were considered ideal for R1, as they enabled as higher MPR reaching up to 1.4 L CH4 (L d)-1. For the system (R1+R2), the supplementation of Fe, Ni and Co promoted operational stability, and assisted in the removal of COD increasing the total efficiency of the system. However it did not favor the MPR, which remained on average of 0.571 L CH4 (L d)-1, and was similar to phase II, without addition of trace elements, with mean of 0.555 L CH4 (L d)-1. Therefore, it was verified that with the addition of trace elements, only R1 would be sufficient for the treatment of vinasse, but, if the treatment in chosen without the addition of trace elements, R2 would be essential for obtaining methane, but, without assurance of operational stability for the anaerobic digestion system. / Mestre
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Estudo experimental da pirólise lenta da casca de arroz em reator de leito fixo /Vieira, Fábio Roberto. January 2018 (has links)
Orientador: Ivonete Ávila / Banca: Pedro Magalhães Sobrinho / Banca: Daniela Andresa Mortari / Resumo: Nessa dissertação é investigada o aproveitamento energético da casca de arroz pela aplicação do processo de pirólise lenta em um reator de leito fixo, o qual foi projetado e construído para realização de trabalho. É estudada a influência dos parâmetros do processo nas características do biochar obtido a partir da casca de arroz, com o objetivo avaliar a sua potencialidade na geração de energia. Para tal foi realizada caracterizações físico-química da casca de arroz in natura e do biochar obtido, aplicando-se diversas técnicas de análise, além da avaliação da eficiência energética. As análises foram estudadas a fim de determinar as condições experimentais que favorecem as características do biochar, tais como poder calorífico superior (PCS) e concentração de carbono fixo, e também o rendimento na produção do mesmo. Foi utilizado um planejamento experimental, conforme metodologia de Taguchi, utilizando-se uma matriz L9 e variando-se os parâmetros que influenciam na pirólise, sendo eles a taxa de aquecimento (β) 5, 10 e 20 ºC/min, temperatura (T) de 300, 400 e 500 ºC, tempo de residência (t) de 3600, 5400 e 7200 s e massa da biomassa in natura (m) de 125, 250 e 500 g. Os resultados indicaram que para os diferentes parâmetros estudados, o maior rendimento de biochar (37,71%) foi observado na condição experimental realizada no teste 7, sendo adotado β=20 ºC/min, T=300 ºC, t=5400 s, e m=500 g. O teste 6 apresentou o maior PCS, 49,05% maior que o da casca de arroz in natura, sendo a... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this dissertation is investigated the utilization of the rice husk means slow pyrolysis process in a fixed bed reactor, which was designed and built to perform work. The influence of the process parameters on the characteristics of the biochar obtained from the rice husk is studied, with the objective of evaluating its potential in the energy. For this purpose, physicalchemical characterization of the in natura rice husk and the biochar obtained were performed, applying several analysis techniques, as well as the energy efficiency assessment. The analyzes were studied in order to determine the experimental conditions favoring the biochar characteristics, such as higher heat value (HHV) and fixed carbon concentration, as well as the yield in the production of the same. An experimental design was used, according to Taguchi's methodology, using a L9 matrix and varying the parameters that influence pyrolysis, being the heating rate (β) 5, 10 and 20 ºC / min, temperature (T) of 300, 400 and 500 ° C, residence time (t) of 3600, 5400 and 7200 if mass of the in natura biomass (m) of 125, 250 and 500 g. The results indicated that the highest biochar yield (37.71%) was observed in the experimental condition performed in test 7, using β = 20 ºC / min, T = 300 ºC, t = 5400 s, in = 500 g. Test 6 showed the highest HHV, 49.05% higher than in natura rice husk, being adopted β = 10 ºC / min, T = 500 ºC, t = 5400 s and m = 125 g. In the condition of higher fixed carbon concentration, test ... (Complete abstract click electronic access below) / Mestre
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Tratamento anaeróbio de efluentes gerados em matadouros de bovinosCristiano Marques de Arruda, Valmir January 2004 (has links)
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Previous issue date: 2004 / Nas atividades agroindustriais, a geração de resíduos mostra-se bastante expressiva, entre as
quais se destacam os matadouros. Em Pernambuco, essas atividades contribuem de maneira
significativa para a crescente poluição dos corpos receptores, uma vez que tecnologias de
tratamento de seus despejos, mesmo existentes, são pouco empregadas. O presente trabalho
avalia os principais aspectos dos matadouros de bovinos da Região Metropolitana do Recife, e
estuda a tratabilidade das águas residuárias geradas no matadouro municipal de Jaboatão dos
Guararapes, através de caracterizações físico-químicas e da utilização da tecnologia
anaeróbia, empregando um reator anaeróbio de fluxo ascendente e manta de lodo (UASB),
instalado em uma estação piloto montada no próprio matadouro, e monitorado durante 460
dias. O monitoramento foi efetuado em 5 fases distintas, onde foram observadas as eficiências
de tratamento do reator em estudo, em função dos efeitos de diferentes valores de velocidade
ascensional, variando o tempo de detenção hidráulica (TDH) e recirculação do efluente. Nas
fases propostas, foram obtidas eficiências de remoção média de DQO bruta na ordem de 76%,
para uma velocidade média ascensional entre 0,08 e 0,50 m/h, com um TDH de 25 horas e
carga orgânica volumétrica (COV) de 3,64 kg DQO/m3.d; 63% para uma velocidade
ascensional entre 0,50 e 1,00 m/h, TDH de 22 horas e COV de 4,26 kg DQO/m3.d; 52% para
uma velocidade ascensional entre 0,50 e 1,00 m/h, TDH de 12 horas e COV de 4,74 kg
DQO/m3.d. Durante a última fase com a redução do TDH para 6 horas, o reator atingiu a
menor média de eficiência com o valor de 33%, para uma velocidade ascensional variando
entre 0,50 e 1,00 m/h e COV de 7,45 kg DQO/m3.d. Durante esta última fase foi realizado um
estudo de pós-tratamento, utilizando um reator de leito de lodo granular expandido (EGSB),
onde foi verificado um ganho na eficiência de remoção de DQO bruta do sistema global
(UASB + EGSB), da ordem de 20%, considerando que nesta fase, foram aplicados valores de
carga orgânica volumétrica de até 31,3 kg DQO/m3.d
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Tratamento de água negra em reator UASB /Pereira, Maria Beatriz de Oliveira Coelho. January 2016 (has links)
Orientador: Gustavo Henrique Ribeiro da Silva / Banca: Adriana Ferreira Maluf Braga / Resumo: O presente trabalho estudou o tratamento de água negra simulada (esgoto sanitário com efluente suíno) em reator UASB (upflow anaerobic sludge blancket) mesofílico com DQO (demanda química de oxigênio) de entrada de 958,489 ± 489,2mg/L, TDH (tempo de detenção hidráulica) de 1,8 ± 1,8d e COV (carga organica volumética) de 0,2 ± 0,2 KgDQO/m³d. Avaliou-se, ainda, o efeito da suplementação de metais traço (Fe, Ni, Mn, Ba, Se, Co e Cu) na AME (atividade metanogênica específica) do lodo utilizado como inóculo de partida do reator. Os ensaios com metais traços foram realizados em batelada utilizando o método Plackett Burman para planejar o experimento. Foram observados valores nitrogênio amoniacal junto a entrada do reator de 197,37 ± 84,3mgN/L, no entanto, o reator apresentou remoção de DQO de 61,7% ± 15%, demonstrando que não houve efeito tóxico da amônia no meio. Os resultados dos ensaios em batelada demonstraram efeito negativo estatisticamente significativo das adições de Ba e Mn sobre a AME, contudo, o Cu e o Se apresentaram efeito positivo, embora não estatisticamente significativos, indicando que a produção de metano a partir de água negra pode ser estimulada com a suplementação desses metais / Abstract: The present work studied the treatment of simulated black water (sewage with swine wastewater) in UASB (upflow anaerobic sludge blancket) mesophilic with input COD (chemical oxygen demand) of 958,489 = 489,2 mg/L, HRT (hydraulic retention time) of 1.8 = 1.8d and OLR (organic loading rate) 0.2 = 0.2 kgCOD/m3d. This work also evaluated the effect of supplementation of trace metals (Fe, Ni, Mn, Ba, Se, Co e Cu) on the SMA (specific methanogenic activity) of the seed inoculum used in reactor startup. The trace metals assay were performed in batch mode using Plackett-Burman method of the design of the experiments. Despite of the ammonia nitrogen values at the inffluet of 197.37 = 84.3 mgN/L reactor, the reactor, the reactor presented COD removal of 61.7% = 15%, indicating no toxic effectof the addition of Ba and Mn on the SMA of the sludge, however, Cu and Se presented positive effect, although not statistically significant, which indicates that the methane production from black water might be enhanceb by the supplementation of these metals / Mestre
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Utvärdering av anaerob behandling av hushållsspillvatten och tekniker för efterbehandling / Evaluation of Anaerobic Treatment of Municipal Wastewater and Techniques for Post-TreatmentGannholm, Catharina January 2005 (has links)
The continuous process of urbanization results in demands on research and development for ecological and sustainable city development. Because of this, the current systems for wastewater treatment may have to be improved. In order to evaluate new technologies for municipal wastewater treatment, a development project has been initiated for the new district Hammarby Sjöstad in Stockholm. The project is lead by the company Stockholm Water. High environmental standards have been put up for the district, as it must be twice as good as an ordinary new district. To achieve this goal, a new water treatment plant is planned to be build. In the testing facility Sjöstadsverket, several new water treatment processes for municipal wastewater are being evaluated. This thesis is concerned with the evaluation of one of these processes. The process in question is anaerobic and consists of the following steps: pre-treatment, UASB (Upflow Anaerobic Sludge Blanket), aerobic polishing for nitrogen reduction, a drum filter and reverse osmosis. The evaluation is performed by analysis of water sample taken from the whole process. It is difficult to make any conclusions about the process as a whole, since not all of the individual parts have been in use at the same time. The production of gas in the UASB system has been quite low. The cause of this is probably that gas is dissolved in the effluent water. The aerobic polishing is sensitive and it will need adjustments of the pH-value in order to treat the water as planned. The use of chemical precipitation of phosphorus over the drum filter does not reduce the amount of phosphorus below the desired level. Furthermore, the demands on the treated water cannot be reached with the use of reverse osmosis, at least not in its current implementation. / Den allt större inflyttningen till städer och tätorter har gjort att behoven av forskning och utveckling kring ekologiskt hållbar stadsutveckling har ökat. Detta innebär i sin tur att det befintliga systemet för avloppsvattenrening kan behöva förändras. För att utvärdera ny och delvis obeprövad teknik inom behandling av avloppsvatten har ett utvecklingsprojekt startat för Stockholms nya stadsdel Hammarby Sjöstad. Stockholm Vatten har fått i uppgift att leda projektet. För stadsdelen har ett antal ambitiösa miljömål formulerats vilka i korthet innebär att stadsdelen skall vara dubbelt så bra som övrig nybyggnation. För att klara dessa miljömål görs förberedelser för ett eget reningsverk i stadsdelen. I Stockholm Vattens pilotanläggning Sjöstadsverket utvärderas en rad olika behandlingslinjer för rening av avloppsvatten från hushåll och syftet med detta examensarbete är att utvärdera en av dessa försökslinjer. Försökslinjen är anaerob och består av försedimentering, UASB (Upflow Anaerobic Sludge Blanket), ett biologiskt poleringssteg för kvävereduktion, trumfilter samt omvänd osmos (RO). Utvärderingen har gjorts genom analyser av vattenprover längs försökslinjen. Det är svårt att dra några slutsatser om linjen som helhet eftersom inte alla ingående komponenter varit igång samtidigt så som planerat. Gasproduktionen över UASB-systemet har varit relativt låg och det beror troligen på att en del av gasen löser sig i det utgående vattnet. Den biologiska poleringen för kvävereduktion är en känslig process som kommer att behöva pH-justeras för att klara att behandla vattnet från Sjöstaden. Med nuvarande utformning av anläggningen kan man inte med kemisk fällning av fosfor över trumfiltret komma ner under utsläppsgränserna. Kraven på utgående vatten kan inte heller nås med den RO som finns på Sjöstadsverket idag.
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Pilot Study on the Treatment of Polluted River Water by an UASB Reactor followed by Constructed WetlandsWu, Cheng-Hsun 18 July 2007 (has links)
Abstract
A system with the combination of upflow anaerobic sludge blanket (UASB) reactor and constructed wetlands (CWLs) has not yet been applied for cleaning river water polluted by sewage and swine wastewaters. In this study, a pilot system with an UASB reactor (effective working volume 4.0 m3) combined with two CWL reactors (effective working volumes 4.8 and 5.4 m3 for CWL-1 and CWL-2, respectively) was used to test the feasibility for treating wastewater sampled from the Wu-Luo River. The river is located in Ping-Tong County of southern Taiwan and has long been polluted by untreated domestic and partially treated swine wastewaters and is among the most polluted rivers in Taiwan. A control system without the UASB reactor and with the CWL-1 and CWL-2 was also tested in parallel to the test system. In the test system, the UASB reactor was seeded with an anaerobic sludge for sewage treatment and CWL-1 and CWL-2 of both the test and control systems were planted with emergent macrophyte (Typha angustifolia L.) and floating macrophyte (Pistia stratiotes L.), respectively. In general, it requires hydraulic retention times (HRT) of 1-5 days for polluted waters in CWLs to obtain clarified ones. In the present study, HRT of the test water in the system was reduced from around 34 to 11 hours to examine the clarification effect.
Results indicated that the influent water has the following average qualities (unit in mg/L): total COD (CODt) 61, BOD 14, suspended solids (SS) 156, total-N 24, ammonia-N 12, nitrate-N 3.9, nitrite-N 0.92, and total-P (TP) 41. Results also indicate with a total HRT of 11.3 hrs, the test system (UASB-CWL1-CML2) could achieve average removals of 62% CODt, 56% BOD, 75% SS, 37% TN, 44% ammonia-N, 54% nitrate-N, 47% nitrite-N, and 61% TP from the influent water. The effluent water has the following average qualities (unit in mg/L):CODt 19, BOD 6.1, SS 15, TN 15, ammonia-N 7.5, nitrate-N 1.8, nitrite-N 0.49, and TP 1.7.
The study indicates that the UASB could act as a preliminary device for sedimentation of most of the influent suspended solids and hence preventing the accumulation of sludge in the following CWLs.
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ANAEROBIC - AEROBIC TREATMENT OF DOMESTIC SEWAGEBanihani, Qais Hisham January 2009 (has links)
Domestic wastewater is the most abundant type of wastewater. Direct discharge of untreated domestic wastewater has environmental and public health risks due to the presence of organics, nutrients and pathogens. Application of anaerobic processes for the treatment of domestic sewage, which at present is largely treated by aerobic processes, has drawn considerable attention recently. Anaerobic processes can be applied for the removal of organic matter (methanogenesis) and nitrogen (anaerobic ammonium oxidation (Anammox)).The toxicity of fluoride to methanogenesis was investigated. The results indicate that acetoclastic were more susceptible to fluoride than hydrogenotrophic methanogens. The concentration of fluoride causing 50% inhibition (IC50) to acetoclastic ranged from 18.1 to 155.7 mg L-1 while for hydrogenotrophic methanogens was > 400.0 mg L-1.The feasibility of a combined system consisting of anaerobic up-flow anaerobic sludge blanket (UASB) followed by aerobic activated sludge (AS) reactor for removal of carbonaceous and nitrogenous contaminants from strong synthetic sewage (2.5 g chemical oxygen demand (COD) L-1) was also studied. The average combined removal of total COD, volatile fatty acids (VFA) and protein was higher than 89.0%, 99.0% and 97.0%; respectively. Extensive nitrification (96.0%) was observed when dissolved oxygen (DO) concentration was > 2.0 mg L-1. In contrast, only partial nitrification occurred when the AS received high organic loads and/or the DO level was below 2.0 mg L-1.The inhibitory effect of nitrite and nitrate on methanogenesis was evaluated. Methanogenic activity was inhibited by the presence of NOx- compounds (i.e., nitrite and nitrate). The inhibition imparted by nitrate was not due to the nitrate itself, but rather to its reduced intermediate, nitrite. The toxicity of NOx- to methanogens was found to be reversible after all the NOx- were reduced during denitrification.Moreover, the development of Anammox enrichment cultures was evaluated. Anammox cultures were successfully developed using sludge samples collected from municipal wastewater treatment plants (WWTPs) as inocula but not from methanogenic granular sludges. Return activated sludge (RAS) collected from WWTP operating for biological nitrogen removal had the highest intrinsic level of Anammox activity. RAS Anammox culture was developed rapidly within 40 days with a doubling time of 6.8 days.
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High Rate Anaerobic Treatment of Complex WastewaterBatstone, Damien John Unknown Date (has links)
High-rate anaerobic degradation of soluble organic pollutants is becoming very popular, particularly for carbohydrate-based industrial wastewaters. Despite the successes achieved, there are significant limitations in the application of this technology to more complex wastewaters. These are defined as containing other organic compounds such as particulate and soluble proteins and fats, and originate from abattoirs (slaughterhouses), meat and food processing and similar industries. Complex wastewater is often difficult to degrade and components such as solids and fats have slow degradation kinetics and can diminish process performance. Also, the growth of granular sludge, which is critical for optimal performance in upflow reactors, is slow and granule properties such as shear strength and settling velocity are poorer. This is reflected in a lower treatment efficiency of 50%-60% in systems treating complex wastewater compared with efficiencies of 85%-95% in carbohydrate fed treatment systems. This thesis examines specific aspects in the treatment of complex (proteinaceous) wastewater in high rate upflow anaerobic treatment plants and the influences of different conversion processes and microbial characteristics on design and operation. The research problem was approached in two ways: The macroscopic conversion processes were examined by investigating and modelling a two-stage full-scale high rate hybrid reactor in Spearwood, Western Australia, designed and operated by ESI Ltd. This allowed localisation of the key conversion process; specifically hydrolysis of solids, which was found to occur mainly within the methanogenic reactor. Degradation of soluble proteins was rapid and all proteins were fully acidified in the acidogenic (first) stage even at very low retention times. Because of the rapid protein degradation rates, partial acidification, which is often a strategy to improve granulation rates, is incompatible with pH, flow and concentration equalisation. The influence of a protein feed on granulation compared with a carbohydrate feed was examined by sampling granules from the above reactor, as well as two full scale brewery fed reactors and a full scale reactor fed fruit and vegetable cannery wastewater. The cannery fed granules had the highest shear strength and settling characteristics while the protein fed granules had low strength and density , low settling velocity and a comparatively wide size distribution. Both brewery fed granules had very similar and suitable properties. Molecular studies using fluorescent in-situ hybridisation (FISH) probing and microscopy indicated that the granules from the complex (protein) wastewater fed reactor had limited structural characteristics , possibly due to limited reaction rates (as opposed to diffusion rates). Granules from the cannery reactor and both brewery reactors had structures that appeared to be the result of diffusion limitations. Therefore, the critical operational constraints when treating complex wastewater are the particulate biomass and particulate substrate. Awareness of process status could be increased by monitoring of biological and substrate solid inventory in the methanogenic reactor. The model developed in this thesis can greatly assist this. Complications due to particulate substrate and poor granule properties may be intrinsic to complex feeds. These constraints are probably best addressed by design of a methanogenic reactor specifically for complex wastewater. The design should attempt to separate substrate hydrolysis, minimise shear on the granules and retain solids.
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Desempenho de reatores anaeróbios de manto de lodo (UASB) operando sob condições de temperaturas típicas de regiões de clima temperadoCampello, Roberto Peres January 2009 (has links)
A pesquisa teve por objetivo avaliar o desempenho de reatores anaeróbios de manto de lodo (UASB) operando sob condições de temperaturas típicas de regiões de clima temperado. Para tanto, foi utilizada uma unidade piloto constituída por três reatores anaeróbios de manto de lodo (UASB), cada um com um volume de 19,2 L. Uma quantidade equivalente de lodo foi disposta nos três reatores para obter uma carga biológica de 0,11 kgDQOkgSVT-1d-1, sendo a origem da biomassa o lodo de um reator UASB tratando efluente de uma indústria de gelatina. Os reatores trataram um esgoto sintético constituído por glicose, acetato, micro e macronutrientes, com concentração de DQO compatível com a de esgotos domésticos. A operação dos reatores foi dividida em duas etapas. Na primeira, aclimatação, os três reatores operaram a temperatura de 35ºC. Na segunda etapa, os reatores operaram com temperaturas de 15, 20, 25, 30 e 35°C Na etapa de aclimatação, os reatores funcionaram muito bem, com remoções de DQO em torno de 90%. Na segunda etapa, observou-se um pequeno decréscimo da remoção de DQO total com a redução da temperatura (95,7, 91,0, 94,2, 90,6 e 87,2% de remoção para 35, 30, 25, 20 e 15ºC, respectivamente). Entretanto, a temperatura não influenciou a remoção de DQO solúvel, o que foi confirmado pela análise estatística aplicada. O volume diário de metano, calculado pelos métodos de balanço de DQO e bioenergética foram semelhantes. Durante os experimentos, devido a interrupções no sistema de energia elétrica, os reatores sofreram choques não intencionais de temperatura, de 5 e 10ºC. Os reatores que apresentaram choques de 5ºC conseguiram se recuperar tão logo houve o restabelecimento das condições iniciais, voltando a apresentar os mesmos graus de remoção de matéria orgânica medidos antes dos choques. Porém, o reator que sofreu um choque da ordem de 10ºC não se recuperou em relação às condições iniciais. Os índices de remoção de matéria orgânica e produção de biogás foram reduzidos, com o concomitante acréscimo na concentração efluente de ácidos graxos voláteis. Em paralelo ao experimento de laboratório, foi monitorado um reator UASB em escala real, construído em Caxias do Sul, cidade que apresenta invernos rigorosos. Neste caso, a influência de outras variáveis na composição dos esgotos domésticos mascararam o possível efeito da temperatura na eficiência do reator. Os reatores protótipos operando com condições controladas de temperatura e concentrações de substrato e vazão estáveis apresentam eficiências de remoção de matéria orgânica significativamente superiores aquelas atingidas no reator UASB de escala real. Os resultados dos experimentos de laboratório conduzidos nesta pesquisa indicaram que houve influência da temperatura na remoção de matéria orgânica de reatores UASB. Contudo, esta influência não causou perda significativa na qualidade do efluente, o que sugere que reatores UASB, operados de maneira cuidadosa, podem ser utilizados como parte de processos de tratamento de esgotos em cidades de clima temperado. / This research assessed the efficiency of Upflow Anaerobic Sludge Blanket (UASB) reactor operating under typical temperatures found in regions with temperate climate. A pilot plant constituted by three 19.2 L anaerobic reactors was operated. Sludge from an UASB reactor treating residuals from a gelatin industrial plant was introduced in each prototype. The initial biological load in each reactor was 0.11 kg CODkg TVS-1.d-1. The reactors treated a synthetic wastewater formed by glucose, acetate, micro and macronutrients, with COD concentration compatible with urban sewage. Reactor’s operation was divided in two phases. In the first, start-up, reactors operated at 35°C. In the second phase, temperatures within reactors were 15, 20, 25, 30, and 35°C. During the start-up and acclimatizing period, COD removal efficiencies were high, around 90%. In the second phase, it was observed that organic matter removal was slightly affected by temperature. Generally, there was a decrease in COD efficiency with temperature reduction (95,7, 91,0, 94,2, 90,6 and 87,2% removal for 35, 30, 25, 20, and 15°C, respectively). However, soluble COD removal was unaffected by temperature, an observation confirmed by statistical analysis. Methane gas volume, calculated by COD mass balances and bioenergetics, was similar. Electric power shortages occurred in some small periods during the experiments. As a consequence, the reactors endured unintentional 5°C and 10°C temperature shocks. Reactors that suffered 5°C shocks recovered very well as soon as they returned to their initial operational temperature. However, the reactor that had a 10°C temperature reduction didn’t recover to its initial efficiency upon return to the original operating temperature. Organic matter removal and biogas production dropped significantly, with a corresponding increase in the volatile organic acids concentration in the reactor effluent. In parallel with the laboratory experiments, it was monitored a full scale UASB reactor operating in Caxias do Sul, a city characterized by cold winters. For the full scale reactor, it was not possible to verify the effect of temperature on efficiency. This was due to the interference of variables other than temperature on the quality of the effluent. The COD removals obtained in the prototype reactors were significantly higher than those measured at the full scale reactor. It has to be considered that the prototypes operated under controlled temperature and constants concentrations and flowrates. On the contrary, the full scale reactor received complex substrates (domestic wastewater), with variations in concentrations, flowrates and temperatures. The results of the research suggest that is feasible to operate UASB reactors in regions where temperature varies significantly around the year, with cold winters and warm summers. Although the experiment showed a small decrease in organic matter removal with temperature, the efficiencies were still high to warrant the application of UASB at lower temperatures. In full scale reactors, a careful operation of the reactor will probably compensate for a small decrease in organic matter removal due to lower temperatures.
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Desempenho de sistemas anaeróbios de alta taxa no tratamento de efluente gerado em unidade de criação de suínos / Performance of high-rate anaerobic systems in treatment of effluent generated in a swine raising unitOlmi, Vanessa Riani 28 February 2002 (has links)
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Previous issue date: 2002-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo deste estudo foi avaliar o desempenho do filtro anaeróbio de fluxo ascendente e do reator anaeróbio de fluxo ascendente e manta de lodo (UASB) no tratamento de efluente líquido gerado em uma unidade de criação de suínos. O experimento foi dividido em três etapas. Na primeira, os reatores foram avaliados separadamente, aplicando-se diferentes cargas orgânicas volumétricas (0,6; 1,0; 2,1; 4,4 e 7,8 kg DQO.m-3.d-1). A eficiência do reator UASB variou de 92,5 a 64,5% e de 97,7 a 68,3%, ao passo que a eficiência do filtro anaeróbio variou de 83,7 a 41,7% e de 93,1 a 56,8% na remoção de DQO e DBO, respectivamente. Os efluentes tratados por ambos os reatores atenderam os padrões da legislação vigente quanto à remoção de DBO quando estes foram operados até carga orgânica de 2,1 kg DQO.m-3.d-1. O efluente tratado pelo reator UASB operando com carga orgânica de até 1,0 kg DQO.m-3.dia-1 atendeu ainda a legislação quanto à remoção de DQO. Na segunda etapa, avaliou-se um sistema combinado constituído do filtro anaeróbio seguido do reator UASB em série, aplicando-se diferentes cargas orgânicas volumétricas (1,8; 3,2; e 5,4 kg DQO.m-3.d-1). Este sistema mostrou ser mais eficiente que os sistemas independentes, principalmente no que se refere à remoção de DQO, apresentando eficiência variando de 90,8 a 77,5% e 93,3 a 78,7% na remoção de DQO e DBO, respectivamente. O efluente tratado pelo sistema combinado atendeu os padrões da legislação vigente quanto à remoção de DBO, quando este foi operado até carga orgânica de 3,2 kg DQO.m-3.d-1, e quanto à remoção de DQO, quando operado com carga orgânica de 1,8 kg DQO.m-3.d-1. Na terceira etapa foi implantado um reciclo de efluente na saída do filtro anaeróbio no sistema combinado, aplicando-se carga orgânica de 5,4 kg DQO.m-3.d-1 no sistema. Para as condições de trabalho utilizadas, a reciclagem aumentou a eficiência do sistema combinado, e as eficiências nas remoções de DQO e DBO foram de 84,2 e 84,9%, respectivamente. O efluente tratado por este sistema não atendeu os padrões da legislação vigente quanto à remoção de DQO e DBO. Nas condições estudadas, as eficiências de remoção de DQO e DBO em função da carga orgânica volumétrica, para ambos os reatores e para o sistema combinado, apresentaram comportamento linear, sendo que quanto menores as cargas orgânicas volumétricas aplicadas, maiores foram as remoções de DQO e DBO. Os efluentes tratados por todos os sistemas estudados, nas condições operacionais avaliadas, estiveram em conformidade com os padrões especificados na legislação vigente quanto ao pH e ao teor de sólidos sedimentáveis. / The objective of this study was to evaluate the performance of an upflow anaerobic filter and upflow anaerobic sludge blanket reactor (UASB) in the treatment of liquid effluent generated in a swine raising unit. The experiment was divided into three stages. In the first stage, the reactors were evaluated separately under different organic loading rates (0.6, 1.0, 2.1, 4.4 and 7.8 kg COD.m-3.d-1). The efficiency of the UASB reactor ranged from 92.5 to 64.5% and from 97.7 to 68.3%, whereas the efficiency of the anaerobic filter ranged from 83.7 to 41.7% and from 93.1 to 56.8% in the removal of COD and BOD, respectively. The effluents treated by both reactors satisfied the limits of current legislation for the removal of BOD when these reactors were operated up to an organic loading rate of 2.1 kg COD.m- 3.d-1. The effluent treated by the UASB reactor operating with an organic loading rate of 1.0 kg COD.m-3.d-1 satisfied the legislation for COD removal. In the second stage, a combined system consisting of the anaerobic filter followed by the UASB reactor was evaluated, under different organic loading rates (1.8, 3.2 and 5.4 kg COD.m-3.d- 1). This system proved to be more efficient than the independent systems, mainly in relation to COD removal, presenting efficiency ranging from 90.8 to 77.5% and 93.3 to 78.7% in the removal of COD and BOD, respectively. The effluent treated by the combined system satisfied the limits of the legislation concerning BOD removal when this system was operated at an organic loading rate of 3.2 kg COD.m-3.d-1 and COD removal when operating at an organic loading rate of 1.8 kg COD.m-3.d-1. In the third stage, effluent recycle was implanted at the exit of the anaerobic filter in the combined system and an organic loading rate of 5.4 kg COD.m-3.d-1 was applied. Under the conditions studied, effluent recycling increased the efficiency of this system, and COD and BOD removal efficiencies were 84.2 and 84.9%, respectively. The effluent generated by this system did not meet the legal limits for COD and BOD removal. Under the conditions studied, the efficiencies of COD and BOD removal as a function of the organic loading rate for both reactors operating separately presented linear behavior, and the lower the organic loading rate applied, the higher were the removals of COD and BOD. The treated effluents for all systems evaluated, under the operational conditions studied, met the limits specified in the current legislation concerning pH and settleable solids contents.
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