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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

REMOÇÃO BIOLÓGICA DE NITROGÊNIO EM ÁGUAS RESIDUÁRIAS ATRAVÉS DE REATOR ANAERÓBIO / REMOÇÃO BIOLÓGICA DE NITROGÊNIO EM ÁGUAS RESIDUÁRIAS ATRAVÉS DE REATOR ANAERÓBIO

Santos, Keliana Dantas 22 February 2007 (has links)
Made available in DSpace on 2015-09-25T12:18:27Z (GMT). No. of bitstreams: 1 KelianaDantasSantos.pdf: 895385 bytes, checksum: 3acd95bf0a090afc60f2e59780dde652 (MD5) Previous issue date: 2007-02-22 / The environmental conditions in Brazil have been contributing to the development of anaerobic systems in the treatment of wastewaters, especially UASB reactors Upflow Anaerobic Sludge Blanket. In the anaerobic digestion, the organic nitrogen is reduced, to ammonium form, which is not degraded in those conditions. The method more used for nitrogen removal is the biological treatment by nitrification and denitrification. The nitrification is an aerobic process, accomplished by autotrophic bacteria that promote the oxidation of ammonia to nitrite and nitrate. The second stage of the treatment, named denitrification, is a process in which anaerobic bacteria reduce nitrite and nitrate to molecular nitrogen. The classic biological process, for removal of nutrients, use three reactors - Bardenpho System, therefore, this work intends an alternative system, where the anaerobic digestion and the denitrification happen in the same reactor, in this system, is reduced for two, the number of reactors. This work had as objective evaluates the performance of the UASB reactor, in terms of removal efficiency, of bath COD and nitrogen. It was verified that the anaerobic digestion process was not affected, the removal efficiency of organic material expressed in COD, in all the phases, was 71%, removal already expected for a reactor of this type. It was also observed that the denitrification process happened, the removal nitrate efficiencies were, in the first phase, 90% and in the following ones, 50%. Therefore, the denitrification process in reactor UASB is viable. / As condições ambientais do Brasil, principalmente o clima por apresentar altas temperaturas, têm contribuído para o desenvolvimento de sistemas anaeróbios no tratamento de águas residuárias, especialmente reatores UASB Upflow Anaerobic Sludge Blanket,. No processo de digestão anaeróbia, o nitrogênio orgânico é reduzido para a forma amoniacal, a qual não é degradada nessas condições. Nos sistemas de tratamento de águas residuárias, o método mais frequentemente utilizado para remoção de nitrogênio é o tratamento biológico por nitrificação e desnitrificação. A nitrificação é um processo aeróbio, realizado por bactérias autotróficas que promovem a oxidação da amônia para nitrito e nitrato. Na segunda etapa do tratamento, desnitrificação, as bactérias facultativas anaeróbias reduzem nitrito e nitrato a nitrogênio molecular. No processo biológico clássico, para remoção de nitrogênio e fósforo, são necessários três reatores - Sistema Bardenpho. Nesta pesquisa, propõe-se um sistema alternativo, onde a metanização e a desnitrificação acontecem no mesmo reator, sendo o número de reatores, desse sistema, reduzido para dois. Este trabalho teve como objetivo avaliar o desempenho de um reator UASB, em termos de eficiência de remoção, de DQO e de compostos de nitrogênio. Verificou-se que o processo de metanização não foi prejudicado, pois, a eficiência de remoção de material carbonáceo expresso em DQO, em todas as fases, foi de 71%, remoção já esperada por um reator deste tipo. Também se observou que efetivamente ocorreu o processo de desnitrificação, visto que as eficiências de remoção de nitrato foram, na primeira fase, de 90% e nas seguintes, em média 50%. Portanto, o processo de desnitrificação em reator UASB é viável.
12

Produção de biogás a partir de glicerol oriundo de biodiesel / Biogas production from glycerol generated on biodiesel industry

Michael Barbosa Viana 29 April 2011 (has links)
Com o aumento da produção de biodiesel para atender à legislação brasileira, está ocorrendo um aumento considerável na geração de glicerol, um resíduo líquido contendo cerca de 46 g\'CL POT.-\'/L e com elevada concentração de matéria orgânica (DQO média de 1.260 g/L). Apesar de ser bastante utilizado na indústria química, o teor de impurezas do glicerol oriundo de biodiesel limita o seu processamento industrial. Buscando agregar valor à este resíduo, utilizou-se um reator anaeróbio de manta de lodo e fluxo ascendente (UASB Upflow Anaerobic Sludge Blanket), em escala de laboratório (14,85 L de volume útil), para produzir metano visando geração de energia, tendo o glicerol residual como única fonte de substrato. Este glicerol residual foi obtido a partir da transesterificação de uma mistura de óleos de algodão e soja (2:3, v/v) em uma usina de biodiesel pertencente à Petrobrás S.A. Durante a operação, a COV foi aumentada gradualmente de 2,0 a 10,0 kgDQO/\'M POT.3\'.d e a diluição de glicerol residual no afluente foi reduzida de 1:1.500 até 1:5. O reator UASB foi capaz de remover, em média, 97,5% de matéria orgânica, apresentando 59% de \'CH IND.4\' no biogás, e relação AGV/Alc\'H\'CO IND.3\'POT.-\' abaixo de 0,3, mesmo com 14 g\'CL POT.-\'/L no interior do sistema. No entanto, foi necessário adicionar nutrientes em concentrações adequadas para evitar que o sistema entrasse em colapso. Os ensaios de toxicidade mostraram que o glicerol residual não é tóxico ao lodo anaeróbio, mas apresenta uma limitação inicial da metanogênese. O teste de biodegradabilidade anaeróbia indicou que o glicerol residual foi 65,9% biodegradável e o potencial de produção de metano alcançou 0,220 \'M POT.3\'CH IND.4\'/kg Glicerol. / The Brazilian legislation demands the use of biodiesel mixed with diesel in an increasing rate. This raise on biodiesel production implies also on an increase on generation of glycerol, which is a liquid or semi-solid waste with high concentration of salts (approximately 46.1 g\'CL POT.-\'/L) and organic matter (1260 gCOD/L in average). Despite being widely used in chemical industry, the residual glycerol contains impurities that limit its industrial processing. In order to add value to this residue, an upflow anaerobic sludge blanket reactor (UASB) at laboratory scale (14.85 L of working volume), fed with glycerol generated on biodiesel industry, was used to produce biogas, which can be used for power generation via methane. This wasted glycerin was produced by the transesterification process of a mixture of the cottonseed oil and soybean oil (2:3, v:v) in a Petrobras S/A biodiesel plant. During operation, the organic loading rate (OLR) was gradually increased from 2.0 to 10.0 kgCOD/\'M POT.3\'.d., and the dilution of residual glycerol in the influent was reduced from 1:1500 to 1:5. The UASB reactor was able to remove 97.5% of the organic matter, producing biogas with 59% of \'CH IND.4\', and VFA/Alk\'H\'CO IND.3\'POT.-\' ratio below 0.3, even with a very high concentration of chloride in the bulk liquid (14 g\'CL POT.-\'/L). However, it was necessary to add nutrients in adequate concentrations to prevent the system from collapsing. The toxicity tests showed that the residual glycerol used in the research was not toxic to the anaerobic sludge. The anaerobic biodegradability test indicated that the residual glycerol was 65.9% biodegradable and the biochemical methane production potential was 0.220 \'M POT.3\'CH IND.4\'/kg Glycerol.
13

PARTIDA DE UM REATOR ANAERÓBIO DE FLUXO ASCENDENTE COM MANTA DE LODO (UASB) NO TRATAMENTO DE EFLUENTES PROVENIENTES DE UMA INDÚSTRIA DE LATICÍNIOS / STARTING A UPFLOW ANAEROBIC SLUGDE BLANKET REACTOR (UASB) IN THE TREATMENT OF EFFLUENT FROM A DAIRY INDUSTRY

Hamerski, Fernando 17 October 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Surface Waters are generally used as support for disposal of waste generated by man. The effluents from dairy industries are characterized by high volume presents, but mainly because of its high concentration of organic load. The evolution of agro-industrial systems wastewater treatment offers the application of eficiente technologies of the environmental impact is kept to a maximum. The UASB (upflow anaerobib sludge blanket) reactor is considered one of the most representative anaerobic systems, due to its high biomass concentration and a rich microbial diversity. This study aimed to initiate and control their operation in the anaerobic digestion process to the treat wastewater from a dairy plant evaluating the removal of control parameters (temperature, pH, COD, BOD5, TKN, TS and VST) beside the design parameters (HRT, HLR and VOL). The reactor was operated with the HRT of 0,085 d-1, and VOLs ranging from 12,58 to 29,2 kg.m-3.d-1, which influenced the high HLR value. To start, the inoculum used was from a septic tank. The temperature oscillations due to the presented experimental period. As for the control parameters, the system showed a significant difference in the removal of organic matter. The removal of BOD5 by the system obtained a removal efficiency of 42,7%. For COD, removal was 58,6%. The removal efficiency was related by large sludge production, indicating the time of withdrawal of excess. The concentration of excess sludge was analyzed, which showed significant 17.538 mg.L-1, being the explicit need for disposal of the sludge during operation. / As águas superficiais geralmente são utilizadas como suporte para eliminação de resíduos produzidos pelo homem. Os efluentes das indústrias de laticínios são caracterizados por apresentarem elevados volumes, mas principalmente por sua elevada concentração de carga orgânica. A evolução dos sistemas de tratamento de efluentes agroindustriais disponibiliza a aplicação de tecnologias eficientes para que o impacto ambiental seja reduzido ao máximo. O reator UASB (upflow anaerobic sludge blanket) é considerado um dos mais representativos sistemas anaeróbios, devido a sua alta concentração de biomassa e uma rica diversidade microbiana. Este trabalho objetivou dar início ao processo bem como controlar sua operação no processo de digestão anaeróbia para o tratamento de efluentes de uma usina de laticínios avaliando a remoção dos parâmetros de controle (temperatura, pH, DQO, DBO5, NTK, ST e SVT), além dos parâmetros de projeto (TDH, TCH e COV). O reator foi operado com um TDH de 0,085 d-1, e COV variando de 12, 58 a 29,2 kg.m-3.d-1, os quais influenciaram no alto valor da TCH. Para a partida, o inóculo utilizado foi proveniente de uma fossa séptica. A temperatura apresentou oscilações devido ao tempo experimental. Quanto aos parâmetros de controle, o sistema apresentou diferença significativa na remoção da matéria orgânica. A remoção de DBO5 pelo sistema obteve-se uma eficiência de remoção de 42,7%. Para a DQO, a remoção foi de 58,6%. A eficiência de remoção foi relacionada pela grande produção de lodo, indicando o momento da retirada do excesso. A concentração do excesso de lodo foi analisada, onde apresentou expressivos 17.538 mg.L-1, ficando explícita a necessidade de descarte do lodo durante a sua operação.
14

Upflow anaerobic sludge blanket reactor : modelling

Rodriguez, Raul January 2011 (has links)
Anaerobic treatment is widely used around the world as a biological stage in both domestic and industrial wastewater-treatment plants. The two principal advantages of anaerobic over aerobic treatment are the production of biogas, which can be used as fuel, and the lower rate of biomass production, which results in lower maintenance costs for the plant. The upflow anaerobic sludge blanket (UASB) reactor is an attractive alternative for regions in hot climates since it works better under mesophilic conditions and it does not need any supporting structure for the development of microorganisms, which grow in the form of granules. In this thesis, a model describing the UASB reactor behaviour with respect to substrate degradation, microorganism growth and granule formation was developed. The model is transient and is based on mass balances for the substrate and microorganisms in the reactor. For the substrate, the processes included in the model are dispersion, advection and degradation of the organic matter in the substrate. The reaction rate for the microorganisms includes the growth and decay of the microorganisms. The decay takes into account the microorganism dying and the fraction of biomass that may be dragged into the effluent. The microorganism development is described by a Monod type equation including the death constant; the use of the Contois equation for describing the microorganism growth was also addressed.  An equation considering the substrate degradation in the granule was required, since in the UASB reactor the microorganisms form granules. For this, a stationary mass balance within the granule was carried out and an expression for the reaction kinetics was then developed. The model for the granule takes into account the mass transport through the stagnant film around the granule, the intraparticle diffusion, and the specific degradation rate. The model was solved using commercial software (COMSOL Multiphysics). The model was validated using results reported in the literature from experiments carried out at pilot scale. A simplified model was also developed considering the case in which the microorganisms are dispersed in the reactor and granules are not formed. The UASB reactor is then described as formed by many well-stirred reactors in series. The model was tested using experimental results from the literature and the sensitivity of the processes to model parameters was also addressed. The models describe satisfactorily the degradation of substrate along the height in the reactor; the major part of the substrate is degraded at the bottom of the reactor due to the high density of biomass present in that region. This type of model is a useful tool to optimize the operation of the reactor and to predict its performance. / QC 20110203
15

Effect of Temperature on Biogas Production in Anaerobic Treatment of Domestic Wastewater UASB System in Hammarby Sjöstadsverk.

Zhao, Chengyuan January 2011 (has links)
The upflow anaerobic sludge blanket (UASB) reactor is widely used around the world to treat variety of domestic andindustrial wastewater with three main advantages: production of biogas as renewable energy, no need of support structure for development of microorganisms and high rate treatment efficiency with low rate of biomass production. This study evaluates the effect of temperature on biogas production and CODtotal removal in Line 4-UASB system treating domestic wastewater in Hammarby Sjöstadsverk. Eight parameters were examined including the following: Influent and effluent temperature, pH, influent CODtotal, influent rate, effluent CODtotal, volatile fatty acids, biogas production rate and methane concentration. There are eight set temperature and each is stabilized for seven days. The biogas production analysis is focus on UASB 1. Temperature rising from 19°C to 35°C achieves a general benefit result in methane yield rate and CODtotal removal efficiency. The best methane yield rate and CODtotal removal rate are 0.167l/gCODtotal and 56.84% respectively at highest working temperature 33.4°C with OLR 3.072gCODtotal/(l*day) and HRT 4.2h. / Den ökande energiförbrukningen i världen och utsläpp av växthusgaser (GHG) gör det nödvändigt att söka nya hållbara energikällor för att matcha efterfrågan på energi i framtiden. Rötningsteknik med organiskt avfall som förnybar energikälla, ger biogas som i genomsnitt består av 78% CH4, 22% av CO2och spår av H2S (<0.5%), är en idealisk kostnadseffektiv metod. Den Uppåt flödande anaeroba slambäddsreaktorn(UASB) med största fördelarna: biogasproduktion som förnybar energi, hög belastning och hög behandlingseffektivitet med låg produktion av biomassa, inget behov av stödstruktur för utveckling av mikroorganismer, är den viktigaste typen för anaerobt reningssystem. Det finns flera faktorer som påverkar UASB-reaktorns prestanda, såsom temperatur, pH, HRT, Uppåtriktat flödeshastighet, OLR, SRT och VFA. I denna studie är huvudsyftet att med fokus på utvärdering av temperaturpåverkan på biogasproduktion och CODtotal avlägsnat i UASB-systemet Linje 4 som behandlar hushållsspillvatten i Hammarby Sjöstadsverk. Analysen avbiogasproduktionen fokuserades på UASB reaktor 1. Åtta parametrar övervakades för att kontrollera skick inklusive inflöde och utflöde, temperatur, pH, CODtotal inflöde, strömningshastighet för inflöde, CODtotal utflöde, flyktiga fettsyror VFA, biogasproduktionstakt och metankoncentration. Försöken utfördes vid åtta inställda temperaturnivåer och varje nivå stabiliserades i sju dagar. pH och VFA-värde var stabilt under hela försöket. Resultatetvisar att temperaturen har en större inverkan på metanavkastningen och CODtotal avlägsnat än belastningen, OLR. Då temperaturen höjs från 19°C till 35°C erhålls en större metanavkastning och större CODtotal avlägsnat. Den största metanavkastningen och CODtotal avlägsnat är 0,167l/g CODtotal respektive 56.84% vid den högsta arbetstemperaturen 33.4°C med OLR 3.072g CODtotal/(l * dag) och HRT 4.2h. Energibalansen vid olika arbetstemperaturer visaratt det finns en stor skillnad i energibehov för uppvärmning och utbyte avenergi i form av biogas. För att minska klimatpåverkan och nå balans mellan input och output av energi måste energibehovet för uppvärmning reduceras. Energiåtervinning från utflöde till inflöde liksom drift av UASB vid låg temperatur är ämnen som kan studeras vid fortsatt arbete.
16

Optimization of Biogas Production by Use of a Microbially Enhanced Inoculum

Doloman, Anna 01 August 2019 (has links)
A renewable energy source, biogas, comprises of methane (80%) and carbon dioxide (15%), and is a great alternative to the conventional fossil-based fuels, such as coal, gas and oil. Biogas is created during anaerobic biological digestion of waste materials, such as landfill material, animal manure, wastewater, algal biomass, industrial organic waste etc. A biogas potential from organic waste in the United States is estimated at about 9 million tons per year and technology allows capture of greenhouse gases, such as methane and carbon dioxide, into a form of a fuel. In the light of global climate change and efforts to decrease carbon footprint of fuels in daily life, usage of biogas as an alternative fuel to fossil fuels looks especially promising. The goal of this research was to develop and test an approach for optimization of biogas production by engineering microorganisms digesting organic waste. Specifically, bacteria that can digest algal biomass, collected from the wastewater lagoons or open waterbodies. The research also expands on the previous efforts to analyze microbial interactions in wastewater treatment systems. A computational model is developed to aid with prognosis of microbial consortia ability to form complex aggregates in reactors with upflow mode of feeding substrate. Combining modeling predictions and laboratory experiments in organic matter digestion will lead to more stable engineered systems and higher yields of biogas.
17

Anaerobic co-digestion of abattoir and textile industry wastewater in a UASB reactor

Ondari, James Maati 04 1900 (has links)
M. Tech. (Civil Engineering, Faculty of Engineering and Technology), Vaal University of Technolog / Textile industry effluents are carcinogenic and highly recalcitrant hence difficult to degrade especially through biological methods. Abattoir effluents are classified under high-strength wastewaters because of their characteristic high organic load hence highly biodegradable. Anaerobic co-digestion is the concept of degrading two effluent streams with complementary characteristics in order to improve the substrate removal rate. The feasibility of co-digesting abattoir and textile wastewater in a UASB reactor was evaluated at mesophilic and ambient temperature conditions. Preliminary experiments were conducted in 500 ml batch reactors to evaluate the optimum abattoir to textile synthetic wastewater ratio. The effect of COD, TVFA, alkalinity and pH on biogas yield was examined at both ambient and mesophilic temperatures. Anaerobic co-digestion of abattoir to textile wastewater in the ratio determined in the batch process was carried out in a 3 L UASB reactor by a continuous process. The continuous biodegradation process was executed at three different HRTs (22, 18 and 14 hrs) over a 60 day operation period. UASB reactor efficiency was achieved at organic loads ranging from 3.0 – 10.8 gCOD L-1 day-1. Continuous mode experiments were carried out at influent flow rates which corresponded to HRTs ranging between 1 to 8 days in order to evaluate the steady state operating parameters for the co-digestion process. The abattoir to textile effluent ratio was found to be 60:40 respectively. The COD, TVFA, alkalinity and pH and biogas yield followed a similar pattern over time at both mesophilic and ambient temperature conditions. Experimental data adequately fit the Grau first order kinetic model and average COD removal efficiencies of 85% and BOD5 of around 96% were achieved. The average biogas yield remained essentially constant, around 0.19 L/g CODremoved. The co-digested mixture was found to be biodegradable judging from the BOD:COD ratio of 0.53. TCOD removal efficiency decreased from 93% to 16% as HRT decreased from 8 days to 1 day. The kinetics of a UASB reactor co-digesting the mixture of synthetic abattoir and textile wastewater was evaluated in this study using Grau second order multicomponent substrate removal kinetic model. The Grau second order kinetic model, whose kinetic coefficient (ks) was 0.389, was found to be suitable for predicting the performance of a lab-scale UASB reactor.
18

Remoção de cistos Giardia spp. e oocistos de Cryptosporidium spp. em sistemas de tratamento combinado (anaeróbio/físico-químico) de água residuária / Removal Giardia spp. cysts and Cryptosporididum spp. oocysts in combined treatment systems (anaerobic/physical-chemical) of wastewater

Oliveira, Gabriela Laila de 18 November 2016 (has links)
O presente estudo visou investigar e monitorar a remoção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. em processos combinados (anaeróbio-físico-químico) de uma estação de tratamento de esgoto (ETE), composta por tratamento preliminar, reator UASB (escala piloto) seguido de coagulação, floculação e sedimentação (equipamento jarteste em escala de bancada) ou coagulação, floculação e flotação por ar dissolvido – FAD (equipamento flotateste em escala de bancada), e verificar a ocorrência desses protozoários no lodo do reator UASB e do processo de sedimentação. Verificou-se a qualidade das amostras a partir de variáveis físicas e químicas, e pela detecção de microrganismos indicadores – E.coli e coliformes totais. Os métodos de detecção de protozoários se basearem 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 e oocistos variaram de 25,9 a 41,2% e de 5,8 a 22,2%, respectivamente. Foram detectadas significativas quantidades de cistos de Giardia spp. em 100% das amostras de esgoto analisadas, com concentrações médias no esgoto bruto de 4,27x103 cistos.L-1 na etapa 1 e 3 (TDH de 12 horas) e 3,18x103 cistos.L-1 na etapa 2 (TDH de 8 horas). No esgoto tratado após processo de sedimentação as concentrações médias foram 327,4 cistos.L-1 no tratamento utilizando coagulante cloreto férrico e 3,8 cistos.L-1 utilizando tanino, ambos na etapa 1, já na etapa 2 esses mesmos tratamentos apresentaram efluente com concentrações médias de 211,6 e 29,6 cistos.L-1, respectivamente. No efluente tratado após o processo de flotação as concentrações médias de cistos de Giardia spp. foram de 8,0 cistos.L-1 com coagulante cloreto férrico e 1,5 cistos.L-1 com PAC, na etapa 3, e de 7,0 cistos.L-1 com cloreto férrico e 5,3 cistos.L-1 com PAC na etapa 2. Os oocistos de Cryptosporidium spp. foram detectados com menor frequência nas amostras de esgoto, como concentrações médias de 18,7 oocistos.L-1 no esgoto bruto nas etapas 1 e 3 e de 23,0 oocistos.L-1 na etapa 2. As eficiências de remoção de cistos de Giardia spp. dos tratamentos combinados variaram de 1,1 log a 3,4 log. O lodo do reator UASB e o lodo da etapa de sedimentação apresentaram altas quantidades de (oo)cistos, evidenciando a tendência de remoção de (oo)cistos por processos físicos como a sedimentação. O processo de flotação foi mais eficiência que o processo de sedimentação na remoção de (oo)cistos, mas devido à pequena quantidade de lodo não foi possível quantificar os (oo)cistos no lodo flotado. / The aim of study was to investigate and monitor the removal of Giardia spp. cysts and Cryptosporididum spp. oocysts through different combined treatment (anaerobic/physicalchemical) of a sewage treatment plant (STP), consisted of preliminary treatment, UASB reactor (pilot scale) followed by sedimentation (jartest equipment in bench scale) or by dissolved air flotation (flotatest equipment in bench scale). Moreover, it was investigated the occurrence of protozoa in the sludge of the UASB reactor and sedimentation process. It was analyzed the quality of the samples through physical and chemical variables and detection of indicator microorganisms – E. coli and total coliforms. The detection methods of protozoa were based on steps of concentration (triple centrifugation or membrane filtration followed by triple centrifugation); purification by immunomagnetic separation (IMS); immunofluorescence assay (IFA). The recovery of cysts and oocysts ranged from 25,9 to 41,2% and from 5,8 to 22,2%, respectively. Significant quantities of Giardia spp. cysts were detected in 100% of the analyzed wastewater samples, with mean concentration of 4,27x103 cysts.L-1 in raw watewater in step 1 and 3 (THD 12 hours) and 3,18x103 cysts.L-1 in step (THD 8 hours). In treated wastewater after the sedimentation process the mean concentration were 327,4 cysts.L-1 with ferric chloride and 3,8 cysts.L-1 with tannin, both in step 1, and in step 2 the same treatments were with mean concentration of 211,6 and 29,6 cysts.L-1, respectively. In treated wastewater after flotation process the mean concentration were 8,0 cysts.L-1 with ferric chloride and 1,5 cysts.L-1 with PAC in step 3 and 7,0 cysts.L-1 with ferric chloride and 5,3 cysts.L-1 with PAC in step 2. The oocysts of Cryptosporidium spp. were detected less often in the wastewater samples, with mean concentration of 18,7 oocysts.L-1 in raw wastewater in steps 1 and 3 and of 23,0 oocysts.L-1 in step 2. The overall removal for Giardia spp. was on average of 1,1 to 3,4 log. The sludge from UASB reactor and sedimentation process presented high quantities of (oo)cysts, implying the tendency of these systems to remove (oo)cysts by its physical processes such as sedimentation. The flotation process was more eficiente than the sedimentation process in the (oo)cysts removal, but due to the small amount of sludge was not possible to quantify the (oo)cysts in the float sludge.
19

Desempenho de reator anaeróbio híbrido (leito fixo e manta de lodo) tratando esgoto sanitário em escala piloto / Performance of anaerobic hybrid reactor (fixed bed and sludge blanket) for sewage treatment in pilot scale

Araujo, Thiago Lopes da Silva 09 June 2014 (has links)
O presente trabalho estudou o aumento de capacidade de tratamento de um reator UASB (Upflow Anaerobic Sludge Blanket) por meio da adição de material suporte para adesão celular (Biobob®), avaliando-se as eficiências de remoção de matéria orgânica (expressa como DQO demanda química de oxigênio) e sólidos em suspensão (expressos como SST sólidos em suspensão totais). O reator híbrido, no qual a biomassa está presente em suspensão e imobilizada no material suporte, foi submetido a baixos tempos de detenção hidráulica (TDH) e altas velocidades ascensionais (vs). A operação do reator anaeróbio, de volume útil igual a 12,5 m³, foi conduzida em duas etapas. Na primeira o sistema foi operado como um reator de manta de lodo e escoamento ascendente (UASB), com TDH de 8,8 h e velocidade ascensional de 0,63 m.h-1. Na segunda etapa, introduziu-se 5,0 m³ de material suporte Biobob® no leito reacional do reator, transformando-o em reator anaeróbio híbrido (HAnR). Nessa condição, variou-se a vazão de alimentação, tendo o TDH variado entre 7,4 h (vs de 0,66 m.h-1) a 3,9 h (vs de 1,25 m.h-1). Para ambas as etapas o sistema foi alimentado com esgoto sanitário à temperatura ambiente, após tratamento preliminar (gradeamento e caixa de areia). Para condições de operação similares, o reator anaeróbio híbrido (HAnR) apresentou melhor desempenho na remoção de DQO e SST que o reator UASB, acrescendo em até 18% e 30% a eficiência de remoção, respectivamente. Para a velocidade ascensional de 1,25±0,02 m.h-1 e TDH de 3,9±0,1 h, o HAnR apresentou concentrações médias no efluente tratado de 205±46 mg DQOt.L-1 e 73±30 mg SST.L-1 e eficiências de remoção de 55±9% DQOt e 63±14% SST. / The increase of the treatability capacity of a UASB (Upflow Anaerobic Sludge Blanket) reactor by introducing an innovative packing material (Biobob®) in its reaction zone was evaluated. The hybrid anaerobic reactor (HAnR) containing suspended and immobilized biomass was evaluated regarding its efficiency of removing organic matter (expressed as COD chemical oxygen demand) and suspended solids (expressed as TSS total suspended solids) under lower hydraulic detention time (HDT) and higher upflow velocities (v s). The anaerobic reactor operation, with 12.5 m³ of working volume, was conducted in two phases. In the first phase, the system was operated as a conventional UASB reactor with HRT of 8.8 h and vs of 0.63 m.h -1 . In the second phase, 5.0 m³ of packing material Biobob® was introduced inside the reaction bed, changing the reactor configuration from suspended growth to hybrid growth. In this condition, the hybrid anaerobic reactor (HAnR) was subjected to decreasing flowrates with HDT ranging from 7.4 h (vs of 0.66 m.h-1) to 3.9 h (vs of 1.25 m.h-1). For both phases, the feed was domestic wastewater (after screens and grit chambers) at ambient temperature. Under similar operation conditions, the HAnR performed better than the UASB reactor increasing at 18% and 30% the COD and TSS removal efficiencies, respectively. For vs of 1.25±0.02 m.h-1 and HDT of 3.9±1.0 h, the HAnR produced a very high quality effluent, with average COD and TSS concentration of 205±46 mg DQOt.L-1 and 73±30 mg SST.L-1 and removal efficiencies of 55±9% and 63±14% for CODt and SST, respectively.
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TRATAMENTO CONJUGADO DE LIXIVIADO COM ESGOTOS DOMÉSTICOS EM REATOR UASB / TREATMENT CONJUGATE IN HOUSEHOLD SEWAGE leached with UASB REACTOR

Ramos, Patrícia Carvalho de Aquino 18 August 2009 (has links)
Made available in DSpace on 2015-09-25T12:23:37Z (GMT). No. of bitstreams: 1 Patricia Carvalho.pdf: 1090354 bytes, checksum: 2030967b9c0c255376ba3167b9a6b633 (MD5) Previous issue date: 2009-08-18 / In terms of the actual Brazilian scenario, 56% of the solid s treatment units produce leachate, 46.8% of this leachate is treated and 70.4% of Brazilian residences are sewered. The development of methods to jointly treat landfill leachate and domestic sewage must recognize the great potential that landfill leachate has as a pollutant and the advantages gained by this combined treatment. The combined treatment of leachate and domestic sewage already exists at full-scale but studies on the optimum levels of dilution of the leachate with sewage are yet to be resolved. The objective of this work was to study the efficiency of a UASB reactor treating landfill leachate in combination with different proportions of domestic sewage, evaluate the influence of the organic loading on the treatment process and develop a biological treatment technology for residual liquids with high pollution loads. The study was carried out between February 2008 and February 2009. The UASB reactor was constructed, installed and monitored at EXTRABES in the municipality of Campina Grande PB. The UASB was constructed in PVC tubing with a diameter of 150mm, 2.35m in height and with a total volume of 41.5L and the treatment consisted of two phases. In the first phase of operation, the UASB reactor was fed with leachate and domestic sewage in ratio of 1:9 by volume respectively, resulting in an AOL of 2.1 kg m-3 d-1. In the second phase of operation the volumetric fraction of leachate was reduced in the proportion of 0.3 to 9.7 of the volume of domestic sewage or 1.6 kg m-3 d-1. The leachate used in this study were from the Metropolitan Landfill in the city of Joao Pessoa and pre-treated for removal of the load of ammonia in piston flow for stripping of ammonia. The domestic wastewater used in this study came from the city where the study was conducted in Campina Grande.In both phases the HRT was 12 hours and the flow of 83L d-1. The influent and effluent of the experimental system were monitored for pH, VFA and TA twice. Analysis of COD, TSS and VSS were monitored weekly. All tests were recommended by APHA (1998). The results show that the combined treatment of landfill leachate diluted domestic sewage in a UASB reactor is technologically feasible alternative and produces effluent with characteristics satisfactory to post-treatment in stabilization ponds. Were obtained removal efficiencies of 44.0, 48.5, 85.4 and 79.9% in the first stage and 59.4, 53.6, 92.7 and 89.8% in the second step for the parameter of COD , STV, TSS and VSS respectively. The second stage had the highest decomposition constants for the parameters of STV, TSS and VSS. It is recommended the continuation of studies of treatment of leachate from landfill diluted sewage with COA than 1.6 kg COD m-3d-1. / No atual cenário brasileiro 56% das unidades de processamento de resíduos drenam lixiviado, apenas 46,8 % tratam esse lixiviado e 70,4% dos domicílios brasileiros são atendidos por rede coletora de esgotamento sanitário. O desenvolvimento de métodos de tratamento integrado de lixiviado e esgotos domésticos é necessário, visto grande potencial poluidor do lixiviado e as vantagens apresentadas nesse tratamento combinado. O tratamento conjugado de lixiviado com esgotos domésticos em escala real já existe, porém, estudar as faixas de diluições de lixiviado para realização do tratamento conjugado em faixas ótimas é imprescindível.Os objetivos deste trabalho foram estudar o desempenho de reator UASB no processo de tratamento de lixiviado combinado com esgotos domésticos em diferentes proporções, avaliar a influência da carga orgânica aplicada no processo de tratamento conjugado de lixiviado e esgoto doméstico em reator UASB e desenvolver tecnologia de tratamento biológico para resíduos líquidos com elevada carga poluidora. O trabalho foi realizado no período de Fevereiro de 2008 a Fevereiro de 2009. O reator UASB foi construído, instalado e monitorado nas dependências físicas da EXTRABES no município de Campina Grande PB. O reator UASB foi construído em tubo de PVC com diâmetro de 150 mm, 2,35 m de altura e volume total de 41,5 L e o tratamento consistiu de duas etapas. Na primeira etapa o reator UASB foi alimentado com lixiviado numa proporção de 1 para 9 vezes o volume de esgoto doméstico, o que resultou numa COA de 2,1 kg m-3dia-1. Na segunda fase de operação a fração volumétrica de lixiviado foi diminuída para a proporção de 0,3 para cada 9,7 vezes o volume de esgoto doméstico ou COA de 1,6 kg m-3 dia-1. O lixiviado utilizado neste trabalho foi proveniente do Aterro Sanitário Metropolitano da cidade de João Pessoa e era pré-tratado para remoção da carga de amônia em reatores de fluxo pistonado para Stripping de amônia. O esgoto doméstico utilizado neste trabalho foi proveniente da cidade onde o estudo foi realizado, Campina Grande-PB. Em ambas as etapas do tratamento o TDH foi 12 horas e a vazão de 83 L.d-1. O monitoramento do sistema experimental foi realizado no afluente e efluente do reator e as análises referentes aos parâmetros pH, AGV e AT foram realizadas duas vezes por semana. As análises referentes aos parâmetros DQO total e solúvel, STV, SST e SSV foram realizadas semanalmente. Todas as análises foram preconizados por APHA (1998). Os resultados mostram que o tratamento conjugado de lixiviado de aterro sanitário diluído em esgotos domésticos em reator UASB é uma alternativa tecnologicamente viável e produz efluente com características satisfatórias para pós-tratamento em lagoas de estabilização. Foram obtidas eficiências de remoção de 44,0; 48,5; 85,4 e 79,9% na primeira etapa e 59,4; 53,6; 92,7 e 89,8% na segunda etapa para os parâmetro de DQO, STV, SST e SSV respectivamente. A segunda etapa apresentou as maiores constantes de decomposição para os parâmetros de STV, SST e SSV. Recomenda-se a continuidade dos estudos de tratamento de lixiviado proveniente de aterro sanitário diluído em esgoto doméstico com COA superior a 1,6 Kg DQO m-3d-1.

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