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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.
501

Análise da Eficiência de Nitrificação em Reatores Biológicos de Leito Móvel (MBBR) em escala de bancada utilizando efluente de Refinaria de Petróleo. / Analyses of Nitrification Efficiency in Bench Scale Moving Bed Biological Reactors (MBBR) using Petroleum Refinery Wastewater.

Gustavo Neves Duarte 07 April 2015 (has links)
As atividades industriais petroquímicas, incluindo as refinarias de petróleo, são grandes consumidoras de água e, consequentemente, grandes geradoras de efluentes industriais contendo uma infinidade de contaminantes. No caso das refinarias de petróleo brasileiras, o nitrogênio amoniacal tem se tornado um componente crítico a ser tratado, o que tem sido feito através de processos de tratamento biológicos que utilizam a nitrificação como base. Neste trabalho, foi avaliada a operação de um reator de leito móvel (MBBR), em escala de bancada, utilizando suportes de polietileno com área específica de 820 m2.m-3, para tratar um efluente proveniente de uma refinaria brasileira com alta concentração de nitrogênio amoniacal. O efluente bruto apresentou demanda química de oxigênio entre 100 e 300 mg.L-1, teores de nitrogênio amoniacal entre 60 e 90 mg.L-1 e condutividade elétrica entre 1 e 2 mS.cm-1. Mesmo com variações da qualidade da alimentação da planta ao longo do estudo, como o aumento das concentrações de contaminantes, incluindo inibidores da nitrificação típicos dos efluentes de refinaria, a planta atendeu à Resolução CONAMA 430/2011 (BRASIL, 2011), que limita a concentração de descarte em 20 mg.L-1 para o contaminante nitrogênio amoniacal, em 93% das medições. Para o caso de uma fictícia legislação mais restritiva, que exigisse limite de 5 mg.L-1 desse contaminante, houve sucesso no tratamento em 83% do tempo, com eficiência média de nitrificação de 93,1%, evidenciando que há uma possibilidade real de utilização do processo MBBR em refinarias brasileiras. / Petrochemical industrial activities, including oil refineries, are major consumers of water and thus generating large industrial wastewater containing a multitude of contaminants. In the case of Brazilian oil refineries, ammonia nitrogen has become a critical component to be treated, what has been done through biological treatment processes using nitrification as a basis. In this work, the operation of a bench scale moving bed reactor was evaluated (MBBR), using polyethylene biomedia with specific area of 820 m2.m-3, to treat an effluent from a Brazilian petroleum refinery containing high concentrations of ammonia nitrogen, was evaluated. The raw effluent contained between 100 and 300 mg.L-1 of Chemical Oxygen Demand, ammonia nitrogen content between 60 and 90 mg.L-1 and electrical conductivity between 1 and 2 mS.cm-1. Even with the variation of feed quality throughout the study, such as the increasing of concentrations of contaminants, including of typical refinery wastewater nitrification inhibitors compounds, the plant has met the legislation CONAMA 430/2011 (BRASIL, 2011), which limits the discarding concentration of ammonia nitrogen in 20 mg.L-1, in 93% of measurements. In the case of a fictitious more restrictive legislation, requiring a discharge concentration limit of 5 mg.L-1 for this contaminant, the treatment was successful in 83% of the time, with an average efficiency of 93.1% nitrification, showing that there is a real possibility to use the MBBR process in Brazilian refineries.
502

Remoção de nitrogênio via Nitrificação e Desnitrificação Simultânea (NDS) em Biorreatores com Membranas Submersas (BRMS)

Silva, Marina Victoretti January 2016 (has links)
Orientadora: Prof.ª Dra Luisa Helena dos Santos Oliveira / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, 2016. / Biorreatores com Membranas Submersas (BRMS) são, atualmente, reconhecidos como opção viável para o tratamento de esgotos sanitários e o reúso de águas. Apesar disso, a tecnologia é geralmente vista como de alto investimento quando comparado a sistemas convencionais de tratamento de esgoto, sobretudo pelo maior gasto energético com aeração do sistema. Porém, BRMS quando operados sob condições específicas para nitrificação e desnitrificação simultâneas (NDS), é possível obter um efluente de elevada qualidade com menor custo, devido a menor necessidade de aeração. Nesse sentido, a operação do sistema de BRMS com o processo de NDS pode aumentar a utilização desta tecnologia no tratamento de esgoto sanitário. Neste contexto, este trabalho teve por objetivo principal avaliar a remoção de nitrogênio via NDS em diferentes concentrações de oxigênio dissolvido (OD) em uma unidade piloto de um Biorreator de Membranas Submersas tratando esgoto sanitário. Para isso, o experimento foi dividido em três Fases de acordo com a concentração de oxigênio dissolvido no licor misto: Fase I (2,3 mgO2/L), Fase II (0,8 mgO2/L e Fase III (0,3 mgO2/L). Foram alcançadas elevadas eficiências de remoção de material orgânico, independente das variações na concentração de OD, DBO5 com valores médios de 98%, 97% e 98% e DQO de 95%, 96% e 95% para as Fases I, II e III, respectivamente. A remoção média de nitrogênio total obtida foi 33% na Fase I, 60% na Fase II e 50% na Fase III. Onde a remoção via NDS foi responsável por 60%, 78% e 74% do total removido para as Fases I, II e III, respectivamente. A remoção de nitrogênio amoniacal não foi limitada devido as baixas concentrações de OD e houve acúmulo de NO2-. O sistema operou sob baixos valores de pressão transmembrana durante todo o período, porém foi encontrada diferença significativa nos valores da Fase III em relação às Fases I e II. Houve uma redução significativa na permeabilidade da membrana quando a concentração de OD no licor misto foi reduzida para 0,3 mg/L, porém sem efeito significativo quando a concentração de OD foi de 0,8 mg/L. Foram observados maiores valores de SPE ligado na Fase III em relação às demais, principalmente na fração de carboidratos que pode estar diretamente ligada a taxa de fouling. Foi possível alcançar remoção de NT em OD de 0,8 mg/L (Fase II) sem causar um impacto negativo no desempenho das membranas, sendo esta fase a mais adequada para a ocorrência do processo de NDS em BRMS. / Submerged Membrane Bioreactors (SMBR) are actually, recognized as viable option for wastewater treatment and reuse. Nevertheless, this technology is generally viewed as a high investment compared to conventional sewage treatment systems, especially for greater energy requirement for aeration system. However, SMBR when operated under specific conditions for simultaneous nitrification and denitrification (SND) it is possible to obtain a high quality effluent with lower compared to the conventional configuration because of less need for aeration. Therefore, the operation of the system SMBR with the NDS process can increase the utilization of this technology in the wastewater treatment. In this context, this study aimed to evaluate the removal of nitrogen via SND under different dissolved oxygen concentrations (DO) in a pilot of a SMBR treating wastewater. For this, the experiment was divided into three phases according to the concentration of dissolved oxygen in the mixed liquor: Phase I (2,3 mgO2/L), Phase II (0,8 mgO2/L and Phase III (0,3 mgO2/L). Were achieved high organic matter removal efficiencies regardless of fluctuations in DO concentration in terms of BOD5 average values of 98%, 97% and 98% and COD average values of 95%, 96% and 95% for Phases I, II and III respectively. The average total nitrogen removal was 33% in Phase I, 60% in Phase II and Phase III 50%. Where the removal means SND is responsible for 60%, 78% and 74% of the total removed for Phases I, II and III respectively. The removal of ammoniacal nitrogen is not limited by the low DO concentrations and there was accumulation of NO2- in Phase III. The system operated under low transmembrane pressure values throughout the period, but significant difference was found in the values of Phase III in relation to phases I and II. There was a significant reduction in membrane permeability when the DO concentration in the mixed liquor was reduced to 0.3 mg/L, but without significant effect when the DO concentration was 0.8 mg/L. It was observed highest bound EPS values in Phase III in relation to the others, mainly in the fraction of carbohydrates that can be directly linked to fouling rate. Satisfactory NT removal was achieved when concentration DO was 0.8 mg/L (Phase II) without causing a negative impact on the performance of membranes, being this phase the most suitable for the occurrence of the SND process in SMBR.
503

Utvärdering av potentiell nitrifikation som metod i markekologiska riskbedömningar : – resultat från en fallstudie på fastigheten Skönsmon 2:12, Sundsvalls kommun

Bergentz, Anna January 2018 (has links)
Miljöriskbedömningar av förorenade områden i Sverige har traditionellt sett främst bedömt saneringsbehovet genom att mäta totalhalter av föroreningarna. Halterna jämförs sedan med riktvärden för att avgöra om de utgör en risk för något av skyddsobjekten. Oftast blir markmiljön det skyddsobjekt som har lägst riktvärde och därmed avgör saneringsbehovet. Kritik har riktats mot att andra faktorer än föroreningshalter borde mätas för att bedöma markkvalitet då den kan vara hög oavsett föroreningssituation. Det är inte heller självklart att en sanering leder till en förbättring av markekosystemet. I Sverige har över 85 000 områden identifierats som potentiellt eller konstaterade förorenade områden. För att förbättra riskbedömningar behövs bättre vägledning om vad som ska ingå i riskbedömningar och för det behövs kunskap om vad som påverkar markfunktionerna.I det här examenarbetet har nitrifikationspotentialen, också kallat ammoniakoxidation, bestämts för 50 jordprover från fastigheten Skönsmon 2:12 i Sundsvalls kommun med hjälp av ISO metoden 15685. Tidigare industriverksamheter på fastigheten har lett till att marken är förorenad med bland annat tungmetaller och polycykliska aromatiska kolväten. Markens förmåga att utföra nitrifikation är en viktig markfunktion för att säkerställa en god markkvalitet. Men vilka markfaktorer som i störst utsträckning påverkar ammoniakoxidationen är inte helt klarlagt, liksom hur olika typer av miljöföroreningar påverkar nitrifikationen. Detta behöver klargöras för att kunna bedöma om ISO-metoden 15685 är ett lämpligt verktyg för markekologiska riskbedömningar av förorenade områden. Nitrifikationsanalysen på de 50 jordproverna har därför jämförts med data över föroreningshalter, markparametrar samt mängden ammoniakoxiderande bakterier och arkéer. Resultatet visar att nitrifikationen på den här lokalen främst påverkas av markparametrarna: totalkväve, organiskt material samt ”tillgänglig” fosfor och i mindre utsträckning av föroreningsnivåerna. Detta betyder att det vid undersökningar av hur föroreningar påverkar nitrifikationen måste finnas referensprover med liknande markkvalitet att jämföra med. Den potentiella nitrifikationen visar också stark korrelation till populationen ammoniakoxiderande bakterier vilket indikerar att de står för det största bidraget till ammoniakoxidationen i marken. / Environmental risk assessment of contaminated sites in Sweden has traditionally mainly assessed the need of remediation by measuring the total concentrations of pollutants. The pollution levels are then compared with guideline values to determine if they represent a risk to any of the protected targets. Most often, the soil environment is the protection target with the lowest guideline value and thus determines the need for remediation.There has been some criticism about using total concentration of pollutants as the only method of assessing soil quality, since soil quality may be high regardless of the situation of the polluted area. In addition, it is not clear if the remediation will always lead to an improvement of the soil quality. In Sweden, more than 85,000 sites have been identified as potential or confirmed contaminated areas. In order to improve risk assessments, better guidance is needed regarding what information should be included. This requires knowledge of which factors are affecting the soil functions.In this thesis, potential nitrification has been determined for 50 soil samples from the property Skönsmon 2:12 in the municipality of Sundsvall using ISO standard 15685. Previous industrial activities on the property have resulted in the soil being contaminated with, for instance, heavy metals and polycyclic aromatic hydrocarbons. The ability of the soil to perform nitrification is an important soil function to ensure good soil quality. However, it is not entirely clear which soil factors affect nitrification to the greatest extent, nor how different types of environmental pollution affect nitrification. This needs to be clarified in order to assess whether ISO 15685 is an appropriate tool for soil ecological risk assessments of contaminated sites. The nitrification data of the 50 soil samples have therefore been compared with data of pollutants, soil parameters, and the amount of ammonia oxidizing bacteria and archaea. This study showed that ammonia oxidation at this site is mainly affected by the soil parameters total nitrogen, organic matter, and “available” phosphorus content, but to a lesser extent of the pollutant levels. This means that when examining how pollutants affect nitrification, reference samples with similar soil quality must be included for comparison. The potential nitrification showed a strong correlation with the population of ammonia oxidizing bacteria, which indicates that they account for the biggest contribution to ammonia oxidation in the soil.
504

Emissão de óxido nitroso e metano em sistemas de manejo do solo e da água / Nitrous oxide and methane emissions in management systems of soil and water

Rosa, Eliete de Fátima Ferreira da 27 January 2014 (has links)
Made available in DSpace on 2016-12-08T15:50:04Z (GMT). No. of bitstreams: 1 PGMS14DA020.pdf: 1241701 bytes, checksum: 696adecfb227383e0ee8edb226ce8b1e (MD5) Previous issue date: 2014-01-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Practices of soil management and use of animal manure as a source of fertilizer affect emissions of greenhouse gases (GHG), which contribute to global warming. The main greenhouse gases produced in agriculture, in addition to carbon dioxide, are nitrous oxide (N2O) and methane (CH4), being issued mainly by the use of animal manure and rice cultivation, respectively. Therefore, three studies were conducted to evaluate the effect of management practices on emissions of N2O and CH4. In study I, the soil was a Humic Dystrudept and the effect of conventional tillage (CT) and no tillage (NT) with and without the application of liquid swine manure systems (DLS) was evaluated. In study II, under the same soil type, the effect of addition of nitrification inhibitor dicyandiamide (DCD) to liquid swine manure (DLS) on the mitigation of greenhouse gases was evaluated. In study III, the soil was a Typic Albaqualf, the effect of continuous and intermittent flooding systems in emissions of CH4 and N2O emissions during the rice cultivation systems were evaluated. Air samples were collected in static chambers and concentration of N2O and CH4 determined by gas chromatography. Approximately 2/3 of the annual N2O emission occurred during the first 90 days after application of DLS. At the end of about a year, the emission factor for N2O in treatments with and without the application of DLS ranged 1-5% of the N applied. The N2O emissions were controlled mainly by the availability of nitrate, total soil porosity filled with water, soil temperature and microbial activity (CO2 flux). The use of DCD with manure reduced approximately 60% of cumulative N2O emissions from NT. The soil revolving on CT may have reduced the efficiency of the inhibitor on N2O emissions, suggesting the need for increased dose of DCD in this soil management. The DCD, delays the onset of nitrate in the soil after application of DLS, reducing N losses and pollution potential of manure. On the Study III, it was found that intermittent irrigation with 60% saturated soil reduced emissions of CH4 about 90% compared to continuous flooding. This system can represent a promising practice in mitigating N2O and CH4 emissions without reducing productivity in rice / Práticas de manejo do solo e utilização de dejetos animais como fonte de fertilizantes afetam as emissões de gases de efeito estufa (GEE), as quais agravam o aquecimento global. Os principais gases de efeito estufa produzidos na agricultura, além do gás carbônico, são o óxido nitroso (N2O) e metano (CH4), sendo emitidos principalmente pela utilização de dejetos animais e no cultivo do arroz irrigado, respectivamente. Diante disso, três estudos foram conduzidos com o objetivo de avaliar o efeito de práticas de manejo nas emissões de N2O e CH4. No estudo I, em um Cambissolo Húmico, avaliou-se o efeito dos sistemas de preparo convencional (PC) e plantio direto (PD) com e sem a aplicação de dejeto líquido de suínos (DLS). No estudo II, em um Cambissolo Húmico, foi avaliado o efeito da adição do inibidor de nitrificação dicianodiamida (DCD) a dejetos suínos na mitigação dos gases. No estudo III, em um Planossolo Háplico, foi avaliado o efeito dos sistemas de alagamento contínuo e intermitente nas emissões de CH4 e N2O durante o cultivo de arroz. Amostras de ar foram coletadas em câmaras estáticas e a concentração de N2O e CH4 foi determinada por cromatografia gasosa. Aproximadamente 2/3 da emissão anual de N2O ocorreu durante os primeiros 90 dias após a aplicação do DLS. Ao final de aproximadamente um ano o fator de emissão de N2O nos tratamentos com e sem a aplicação de DLS variou de 1 a 5% do N aplicado. As emissões de N2O foram controladas principalmente pela disponibilidade de nitrato, porosidade total do solo preenchida por água, temperatura do solo e atividade microbiana (fluxo de CO2). A utilização de DCD junto aos dejetos reduziu aproximadamente 60% das emissões acumuladas de N2O no PD. O 10 revolvimento do solo no PC pode ter reduzido a eficiência do inibidor nas emissões de N2O, sugerindo a necessidade de maior dose de DCD neste sistema de manejo do solo. A DCD, ao retardar o aparecimento de nitrato no solo após a aplicação de DLS, reduz as perdas de N e o potencial poluidor dos dejetos. Com relação ao estudo III, verificou-se que o sistema de irrigação intermitente com 60% de saturação do solo reduziu as emissões de CH4 em cerca de 90% em relação ao sistema de alagamento contínuo. Esse sistema pode ser uma prática promissora na mitigação das emissões de N2O e CH4, sem redução de produtividade na cultura do arroz
505

Biodegradation of cyanide and subsequent nitrification-aerobic denitrification in cyanide containing watewater

Mekuto, Lukhanyo January 2014 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014 / Environmental legislation focusing on wastewater disposal in industries that utilise cyanide and/or cyanide-related compounds has become increasingly stringent worldwide, with many companies that utilise cyanide products required to abide by the Cyanide International Code associated with the approval of process certifications and management of industries which utilise cyanide. This code enforces the treatment or recycling of cyanide-contaminated wastewater. Industries such as those involved in mineral processing, photo finishing, metal plating, coal processing, synthetic fibre production, and extraction of precious metals, that is, gold and silver, contribute significantly to cyanide contamination in the environment through wastewater. As fresh water reserves throughout the world are low, cyanide contamination in water reserves threatens not only the economy, but also endangers the lives of living organisms that feed from these sources, including humans. In the mining industry, dilute cyanide solutions are utilised for the recovery of base (e.g. Cu, Zn, Ni, etc.) and precious metals (e.g. Au, Ag, etc.). However, for technical reasons, the water utilised for these processes cannot be recycled upstream of the mineral bioleaching circuit as the microorganisms employed in mineral bioleaching are sensitive to cyanide and its complexes, and thus the presence of such compounds would inhibit microbial activity, resulting in poor mineral oxidation. The inability to recycle the water has negative implications for water conservation and re-use, especially in arid regions. A number of treatment methods have been developed to remediate cyanide containing wastewaters. However, these chemical and physical methods are capital intensive and produce excess sludge which requires additional treatment. Furthermore, the by-products that are produced through these methods are hazardous. Therefore, there is a need for the development of alternative methods that are robust and economically viable for the bioremediation of cyanide-contaminated wastewater. Biological treatment of free cyanide in industrial wastewaters has been proved a viable and robust method for treatment of wastewaters containing cyanide. Several bacterial species, including Bacillus sp., can degrade cyanide to less toxic products, as these microorganisms are able to use the cyanide as a nitrogen source, producing ammonia and carbon dioxide. These bacterial species secrete enzymes that catalyse the degradation of cyanide into several end-products. The end-products of biodegradation can then be utilised by the microorganisms as nutrient sources. This study focused on the isolation and identification of bacterial species in wastewater containing elevated concentrations of cyanide, and the assessment of the cyanide biodegradation ability of the isolates. Thirteen bacterial isolates were isolated from electroplating wastewater by suppressing the growth of fungal organisms and these species were identified as species belonging to the Bacillus genus using the 16S rDNA gene. A mixed culture of the isolates was cultured in nutrient broth for 48 hours at 37°C, to which FCN as KCN was added to evaluate the species‟ ability to tolerate and biodegrade cyanide in batch bioreactors. Subsequently, cultures were supplemented solely with agro-waste extracts, that is, Ananas comosus extract (1% v/v), Beta vulgaris extract (1% v/v), Ipomea batatas extract (1% v/v), spent brewer‟s yeast (1% v/v) and whey (0.5% w/v), as the primary carbon sources. Owing to the formation of high ammonium concentration from the cyanide biodegradation process, the nitrification and aerobic denitrification ability of the isolates, classified as cyanide-degrading bacteria (CDB) was evaluated in a batch and pneumatic bioreactor in comparison with ammonia-oxidising bacteria (AOB). Furthermore, the effects of F-CN on the nitrification and aerobic denitrification was evaluated assess the impact of F-CN presence on nitrification. Additionally, optimisation of culture conditions with reference to temperature, pH and substrate concentration was evaluated using response surface methodology. Using the optimised data, a continuous biodegradation process was carried out in a dual-stage packed- bed reactor combined with a pneumatic bioreactor for the biodegradation of F-CN and subsequent nitrification and aerobic denitrification of the formed ammonium and nitrates. The isolated bacterial species were found to be gram positive and were able to produce endospores that were centrally located; using the 16S rDNA gene, the species were found to belong to the Bacillus genus. The species were able to degrade high cyanide concentration in nutrient broth with degradation efficiencies of 87.6%, 65.4%, 57.0% and 43.6% from 100 mg F-CN/L, 200 mg F-CN/L, 300 mg F-CN/L, 400 mg F-CN/L and 500 mg F-CN/L respectively over a period of 8 days. Additionally, the isolates were able to degrade cyanide in an agro-waste supported medium, especially in a medium that was supplemented with whey which achieved a degradation efficiency of 90% and 60% from 200 mg F-CN/L and 400 mg F-CN/L, respectively over a period of 5 days. The nitrification ability of the isolates was evaluated and the removal of NH4 +/NO3 - by the CDB and AOB in both shake flasks and pneumatic bioreactor was determined to be pH dependent. The maximum NH4 +/NO3 - removal evaluated over a period of 8 days for CDB and 15 days for AOB, observed at pH 7.7 in shake flasks, was 75% and 88%, respectively, in the absence of F-CN. Similarly, the removal of NH4 +/NO3 - in a pneumatic bioreactor was found to be 97.31% for CDB and 92% for AOB, thus demonstrating the importance of aeration in the designed process. The nitrification by CDB was not inhibited by cyanide loading up to a concentration of 8 mg FCN/ L, while the AOB were inhibited at cyanide loading concentration of 1 mg F-CN/L. The CDB removed the NH4 +/NO3 - in PBSs operated in a fed-batch mode, obtaining efficiencies >99% (NH4 +) and 76 to 98% (NO3 -) in repeated cycles (n = 3) under F-CN (≤8 mg F-CN/L). The input variables, that is, pH, temperature and whey-waste concentration, were optimised using a numerical optimisation technique where the optimum conditions were found to be: pH 9.88, temperature 33.60 °C and whey-waste concentration 14.27 g/L, under which 206.53 mg CN-/L in 96 h can be biodegraded by the microbial species from an initial cyanide concentration of 500 mg F-CN/L. Furthermore, using the optimised data, cyanide biodegradation in a continuous mode was evaluated in a dual-stage packed-bed bioreactor connected in series to a pneumatic bioreactor system used for simultaneous nitrification including aerobic denitrification. The whey-supported Bacillus sp. culture was not inhibited by the free cyanide concentration of up to 500 mg F-CN/L, with an overall degradation efficiency of ≥99% with subsequent nitrification and aerobic denitrification of the formed ammoniu and nitrates over a period of 80 days.
506

Análise da Eficiência de Nitrificação em Reatores Biológicos de Leito Móvel (MBBR) em escala de bancada utilizando efluente de Refinaria de Petróleo. / Analyses of Nitrification Efficiency in Bench Scale Moving Bed Biological Reactors (MBBR) using Petroleum Refinery Wastewater.

Gustavo Neves Duarte 07 April 2015 (has links)
As atividades industriais petroquímicas, incluindo as refinarias de petróleo, são grandes consumidoras de água e, consequentemente, grandes geradoras de efluentes industriais contendo uma infinidade de contaminantes. No caso das refinarias de petróleo brasileiras, o nitrogênio amoniacal tem se tornado um componente crítico a ser tratado, o que tem sido feito através de processos de tratamento biológicos que utilizam a nitrificação como base. Neste trabalho, foi avaliada a operação de um reator de leito móvel (MBBR), em escala de bancada, utilizando suportes de polietileno com área específica de 820 m2.m-3, para tratar um efluente proveniente de uma refinaria brasileira com alta concentração de nitrogênio amoniacal. O efluente bruto apresentou demanda química de oxigênio entre 100 e 300 mg.L-1, teores de nitrogênio amoniacal entre 60 e 90 mg.L-1 e condutividade elétrica entre 1 e 2 mS.cm-1. Mesmo com variações da qualidade da alimentação da planta ao longo do estudo, como o aumento das concentrações de contaminantes, incluindo inibidores da nitrificação típicos dos efluentes de refinaria, a planta atendeu à Resolução CONAMA 430/2011 (BRASIL, 2011), que limita a concentração de descarte em 20 mg.L-1 para o contaminante nitrogênio amoniacal, em 93% das medições. Para o caso de uma fictícia legislação mais restritiva, que exigisse limite de 5 mg.L-1 desse contaminante, houve sucesso no tratamento em 83% do tempo, com eficiência média de nitrificação de 93,1%, evidenciando que há uma possibilidade real de utilização do processo MBBR em refinarias brasileiras. / Petrochemical industrial activities, including oil refineries, are major consumers of water and thus generating large industrial wastewater containing a multitude of contaminants. In the case of Brazilian oil refineries, ammonia nitrogen has become a critical component to be treated, what has been done through biological treatment processes using nitrification as a basis. In this work, the operation of a bench scale moving bed reactor was evaluated (MBBR), using polyethylene biomedia with specific area of 820 m2.m-3, to treat an effluent from a Brazilian petroleum refinery containing high concentrations of ammonia nitrogen, was evaluated. The raw effluent contained between 100 and 300 mg.L-1 of Chemical Oxygen Demand, ammonia nitrogen content between 60 and 90 mg.L-1 and electrical conductivity between 1 and 2 mS.cm-1. Even with the variation of feed quality throughout the study, such as the increasing of concentrations of contaminants, including of typical refinery wastewater nitrification inhibitors compounds, the plant has met the legislation CONAMA 430/2011 (BRASIL, 2011), which limits the discarding concentration of ammonia nitrogen in 20 mg.L-1, in 93% of measurements. In the case of a fictitious more restrictive legislation, requiring a discharge concentration limit of 5 mg.L-1 for this contaminant, the treatment was successful in 83% of the time, with an average efficiency of 93.1% nitrification, showing that there is a real possibility to use the MBBR process in Brazilian refineries.
507

Avaliação da remoção de nitrogênio via nitrificação e desnitrificação simultânea em um reator biológico com leito móvel (IFAS). / Evaluation of nitrogen removal through simultaneous nitrification and denitrification in Integrated Fixed-film Activated Sludge (IFAS).

Daniel Vieira Minegatti de Oliveira 07 December 2015 (has links)
O fenômeno conhecido como Nitrificação e Desnitrificação Simultânea (SND) significa que em um mesmo reator ocorre simultaneamente a nitrificação e a desnitrificação, sob condições de operações idênticas, podendo ser justificada principalmente pela teoria de microambiente no floco ou biofilme. Assim, em um único reator, sob condições controladas de oxigênio dissolvido (OD) e elevados tempos de residênciacelular épossível que ocorra a nitrificação e a criação de zonas anóxicas no interior dos flocos ou biofilme para a ocorrência da desnitrificação. Neste sentido, a tecnologia MBBR/IFAStem como característicaelevado tempo de residência celular do biofilme formado nos meios suporte presentes no reator. Deste modo, neste estudo avaliou-se a remoção de nitrogênio via SND em um sistema IFAS quando submetido a diferentes concentrações de OD e Tempo de DetençãoHidraulica de 5,5 e 11 horas, tratando efluente sanitário e efluente sintético. Os resultados experimentais demonstraram que pode ser possível desenvolver efetiva SND com concentrações de OD média de 1,0 mg.L-1 e 1,5 mg.L-1. Sendo que, foram obtidas eficiência média de remoção de NTde cerca de 68% e concentrações médias efluente de N-NH4 de aproximadamente 5,0 mg L-1, de N-NO3 inferiores a 4,5 mg L-1 e de N-NO2 em torno de 0,1 mg L-1, e com eficiência média de remoção DQO solúvel acima de 90%, quando empregado efluente sintético. Ademais, por meio da avaliação da emissão de Óxido Nitroso (N2O), foi possível comprovar que a desnitrificação ocorreu de forma efetiva. / The phenomenon known as Simultaneous Nitrification and Denitrification (SND) means that in the same reactor simultaneously occurring nitrification and denitrification under identical operations conditions, and can be mainly explained by the microenvironment theory inside the floc or biofilm. Therefore, in a single reactor under controlled conditions of dissolved oxygen (DO) and high Solids Retention Time (SRT) it is possible that the nitrification happens and the creation of anoxic zones within the flocsor biofilm to the occurrence of the denitrification. In this sense, the MBBR/IFAS technology is characterized by high SRT of the biofilm formed on the carriers present in the reactor. Thereby,this work evaluated the nitrogen removal through SND in a IFAS system when submitted to different DOconcentrations and Hydraulic Retention Time of 5.5 hours and 11.0 hours, treating domestic and synthetic effluents. The experimental results showed that it may be possible to develop effective SND withaverage concentrations of DO of 1.0 mg L-1 and 1.5 mg L-1. It was obtained a TN average removal efficiency about 68%, and an average effluent concentration of NH4-N of approximately 5.0 mg L-1, of NO3-N less than 4.5 mg L-1 and ofNO2-N around 0.1 mg L-1, and an average CODsoluble removal efficiency above 90%, employing synthetic effluent. Furthermore, by evaluating the Nitrous Oxide(N2O) emission, it was possible to prove that the denitrification occurred effectively.
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Remoção de nitrogênio e material orgânico via nitrificação e desnitrificação simultânea (NDS) em biorreator de membranas submersas com biofilme (BRMS-BF) para o tratamento de águas urbanas servidas

Salcedo, Alvaro Javier Moyano January 2018 (has links)
Orientador: Prof. Dr. Eduardo Lucas Subtil / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Santo André, 2018. / O lançamento de águas urbanas servidas (AUS) sem tratamento causa problemas associados à saúde pública e à deterioração dos recursos hídricos. Neste contexto, os Biorreatores com Membranas Submersas (BRMS) e Biofilme (BRMS-BF), operados sob condições específicas para nitrificação e desnitrificação simultâneas (NDS), são uma opção viável para o tratamento de água AUS e seu potencial reúso. Este projeto de pesquisa teve como objetivos avaliar a remoção de nitrogênio via NDS, caracterizar o processo de fouling das membranas e identificar os principais microrganismos associados ao ciclo do nitrogênio em um sistema piloto BRMS-BF operado em diferentes concentrações de oxigênio dissolvido (OD) para o tratamento de AUS. O volume útil do reator foi de 156 L com módulo de 17 membranas (sintetizadas em fluoreto de vinilideno, PVDF) tipo placa plana de ultrafiltração de 0,1 ?m. O material suporte foi de poliuretano (gel termoplástico). O efluente utilizado foi da residência estudantil e o restaurante universitário da Universidade de São Paulo. Foram propostas duas fases de operação com concentrações de OD acima de 2, e 0,8 mgO2/L. Os valores de temperatura (T), Potencial de Redox (ORP), e pressão transmebranar (PTM) foram monitorados e os de pH, vazão (Q) e OD controlados, por meio de sensores. A aeração foi realizada controlando o fluxo através de rotação por meio de dois difusores de ar de 10 e 15 L/min. Os resultados para a fase I e II apresentaram os valores médios a seguir, respetivamente: T (24 e 23 ?), ORP (186 e -11 mV), PTM (0,02 e 0,04 bar), pH (6,9 e 6,7), Q (22 e 16 L/h), OD (2,2 e 0,9 mgO2/L) e SST (5,7 e 5,6 g/L). A remoção de matéria orgânica (DQO e DBO5 mg/L) e de turbidez foi maior de 96% e de 99%, respetivamente nas duas fases. A remoção de nitrogênio total foi de 33% para a Fase I e 74% na Fase II, apresentando melhoras na remoção a baixa concentração de OD. No entanto, a Fase II apresentou acúmulo de nitirto, que pode estar relacionado com a desnitrificação parcial, devido a ausência de carbono suficiente em presença de baixas concentrações de OD. As comindades de microrganismos observadas perteneceram principalmente ao filo Petrobacteria (abundância relativa > 70% na biomassa suspensa e o biofilme para a Fase I e II). O gênero Nitrospira foi o principal gênero identificado que influenciou o processo de oxidação de nitirito. Não foi encontrada diferença significativa entre os microrganismos presentes segundo o tipo de biomassa e a concentração de OD. Não houve uma redução significativa na permeabilidade das membranas, associada ao fouling, quando a concentração de OD foi reduzida para 0,9 mg/L. / Urban waters served (UWS) without any kind of treatment causes problems which are related to public health and hydric resources deterioration. In this context, the Submerged Membranes Bioreactor (MBRS) and Biofilm (MBRS-BF), operated under specific conditions for simultaneous nitrification-denitrification (SND), are a viable option for UWS treatment and their potential reuse. The aim of this project is to evaluate nitrogen removal via SND, characterize the process of fouling of the membranes and identify the main microorganisms related to nitrogen cycle in a MBRS-BF pilot-system which was operated on different concentrations of dissolved oxygen (DO) for UWS treatment. Reactor useful volume was 156 L with 17-membranes module - (synthesized in a Polyvinylidene Fluoride - PDVF) - 0,1 ?m ultrafiltration flat-plate type. Support material was composed of polyurethane (thermoplastic gel). The used effluent has come as from student residence as USP's food court. Two operation-phases were proposed in which concentration was over 2, and 0,8 mgO2/L. Temperatures values (T), Redox potential (ORP) and trasmembrane pressure(TMP) was monitored as well as pH, leakage (L) and DO was controlled by sensors. Aeration was carried out by controlling flow in rotation through two air diffusers with 10 e 15 L/min capacity. The results for phases I and II performed the following average values, respectively: T (24 and 23), ORP (186 and -11 mV), PTM (0,02 and 0,04 bar), pH (6,9 and 6,7), Q (22 and 16 L/h), OD (2,2 and 0,9 mgO2/L) and SST (5,7 and 5,6 g/L). Organic matters removal (DQO and DBO5 mg/L) and turbidity was bigger, by ranging from 96% to 99%, respectively, in both phases of this operation. Total nitrogen removal was 33% for Phase I and 74% of Phase II, by perfoming best efficiency in concentration of low OD (0,9mgO2/L).However, phase II showed nitrite storage, which can be attributed to partial denitrification, due to absence of carbon enough in OD low concentrations. Observed microorganisms communities belonged to mainly Petrobacteria phylum (relative abundance > 70% in suspended biomass and biofilm for phases I and II). Nitrospira was the main genus found which influenced nitrite oxidation process. It was not found significant difference among these present microorganisms according to their biomass type and DO concentration. There were not any significant reduction on membranes permeability, related to fouling, when DO concentration was reduced to 0,9 mg/L.
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Tratamento de esgotos pelo sistema combinado filtro anaerobio e filtros de areia / Water treatment by the combination of an upflow anaerobic filter and sand filter

Tonetti, Adriano Luiz, 1973- 25 February 2008 (has links)
Orientadores: Bruno Coraucci Filho, Roberto Feijo de Figueiredo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T03:44:49Z (GMT). No. of bitstreams: 1 Tonetti_AdrianoLuiz_D.pdf: 1722600 bytes, checksum: e50780c638866b2c1f1ca142ed978993 (MD5) Previous issue date: 2008 / Resumo: Nesta pesquisa estudou-se um sistema para o tratamento de esgotos de pequenas comunidades composto pela combinação de filtro anaeróbio com filtro de areia e reator de desnitrificação. Para isso foi avaliada a partida e a operação de três filtros anaeróbios com recheio de bambu operados com tempo de detenção hidráulica nominal de 9 horas, sendo o efluente gerado disposto sobre os leitos de quatro filtros de areia em distintas taxas de aplicações. No primeiro filtro de areia aplicaram-se 50 Lm-2 uma vez por dia. No segundo, terceiro e quarto filtro, esta mesma carga foi disposta em dois, três e quatro horários, espaçadas entre as 9 horas e às 16 horas, correspondendo às taxas de 100, 150 e 200 Lm2dia. Cada filtro de areia era seguido por um reator de desnitrificação em que se buscou um meio propício à remoção do nitrogênio, objetivando adequar o efluente ao lançamento em um corpo hídrico e como água de reúso. O sistema foi avaliado quanto a parâmetros físicos, químicos e biológicos. Como resultado, o efluente atendeu a legislação de Minas Gerais e São Paulo quanto a DQO e DBO e, após a correção do pH e adição de efluente anaeróbio como fonte de carbono, obteve-se uma remoção de 43,5% de N-total no reator em que se aplicou 50 Lm-2dia-1, passando a ter um grau moderado para a prática agrícola. Palavras-chave: esgoto, filtro de areia, tratamento, desnitrificação, reúso / Abstract: The main objective of this research was to study an onsite system to treat the wastewater from small villages. The system was constituted by the combination of an upflow anaerobic filter followed by a sand filter and a denitrification reactor. The start up and the operation of three upflow anaerobic filters filled with bamboo rings were evaluated. These filters were operated with hydraulic detention time of 9 hours. The produced effluent was disposed over four sand filters in different frequencies of application. On the first sand filter, 50 Lm-2 were applied once a day. On the second, the third and the fourth filters, the same load was disposed in twice, three and four times a day, distributed between 9 am and 4 pm. Each sand filter was followed by a denitrification reactor aiming at the removal of total nitrogen, thus making appropriate the effluent for discharge or water reuse. Weekly, the system was evaluated by analyses including physical, chemical and biological parameters. As a result, the effluent was suitable for the COD and BOD legislation and, after the pH correction and the addition of external carbon source, a removal of 43,5% from total-N was reached in the reactor which received a load of 50 Lm-2dia-1, consequently the effluent was ready to be used within a slight to moderate degree of restriction. Keywords: wastewater, sand filter, treatment, denitrification, reuse / Doutorado / Saneamento e Ambiente / Doutor em Engenharia Civil
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Tratabilidade de esgoto sanitario contendo formaldeido em um sistema combinado filtro anaerobio-biofiltro aerado submerso / Treatability of domestic wastewater containing folmaldehyde in a combined system anaerobic filter and biological aerated filter

Castagnato, Renata 29 August 2006 (has links)
Orientador: Edson Aparecido Abdul Nour / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T03:49:57Z (GMT). No. of bitstreams: 1 Castagnato_Renata_M.pdf: 1224635 bytes, checksum: 513cfc1c14b5af1159379a00e5d00297 (MD5) Previous issue date: 2006 / Resumo: O formaldeído é um composto orgânico muito utilizado em diversos setores da indústria e serviços de saúde. Em hospitais e laboratórios de anatomia, ele é empregado em solução de 8 a 10 %, que ao se tornar imprópria para uso, necessita ser disposta adequadamente para não afetar os ecossistemas presentes nos corpos d¿água ou nos processos biológicos das estações de tratamento de esgotos. Pois, dependendo da concentração que o formaldeído se encontra, pode ser extremamente tóxico. O presente estudo teve o objetivo de verificar a tratabilidade de esgoto sanitário contendo formaldeído em um sistema combinado composto de um filtro anaeróbio (FA) seguido de um biofiltro aerado submerso (BAS). O volume útil de cada reator era de 17,6 L e o tempo de detenção hidráulica de 12 h. As concentrações de formaldeído aplicadas ao esgoto sanitário afluente ao sistema foram de 50, 100, 200 e 400 mg L-1, dividas em quatro fases de operação. Durante o monitoramento do sistema, foi verificado que a eficiência de remoção de formaldeído variou de 85,0 a 99,4 %, sendo que a partir do início da segunda fase (quando a concentração aplicada era de 100 mg L-1), a média de remoção foi de 98,0 ± 1,2 %. A média de remoção de DQO, durante as quatro fases de aplicação, foi de 84,4 ± 7,3 %, apesar do formaldeído não ter sido a única fonte de carbono. O valor máximo de carga de formaldeído removida no sistema foi de 0,407 kgm-3 d-1, quando sua aplicação no esgoto bruto era de 0,411 kg m-3 d-1 (concentração de 410,8 mg L-1). Foi observado também que a maior concentração de formaldeído encontrada no efluente tratado pelo sistema foi de 5,8 mg L-1, com valor médio de 1,9 ± 1,4 mg L-1. Houve inibição do processo de nitrificação no BAS a partir de 50 mg L-1 de formaldeído presente no esgoto afluente. Verificou-se que o sistema proposto foi adequado ao tratamento de esgoto sanitário com formaldeído, pois em todas as concentrações do composto aplicado (0 a 410,8 mg L-1), o seu desempenho se manteve estável, principalmente com relação à remoção de DQO e do próprio formaldeído. Palavras-chave: Formaldeído, sistema combinado anaeróbio/aeróbio, filtro anaeróbio, biofiltro aerado submerso, nitrificação, esgoto sanitário / Abstract: Formaldehyde is an organic compound largely used in several industrial sectors and health services, for example in hospitals and anatomy laboratories in a proportion of 8 to 10 %. When it becomes inadequate to be used, this solution must be properly disposed in order not to affect the ecosystems in water streams or in the biological process in the treatment sewage works, because depending on its concentration it can be extremely toxic. This study aims to verify the treatability of domestic wastewater containing formaldehyde in a combined system formed by an Anaerobic Filter followed by a Biological Aerated Filter. Each reactor presented a volume of 17,6 l and 12 h of hydraulic retention time (HRT). This type of system aggregates the advantages of these combined processes: anaerobic and aerobic. The concentration of formaldehyde used in domestic wastewater influent in the system was divided into 4 phases of operation, which corresponded to 50, 100, 200 and 400 mg L-1. The efficacy of removal of formaldehyde in the system varied from 85,0 and 99,4 %, and it must be noted that from the beginning of the 2nd phase (100 mg L-1) the average of removal was 98,0 ± 1,2 %. The average of removal of COD, during the whole 4 phases of operation, was 84,4 ± 7,3 %. It must be said that formaldehyde was not the only carbon source. The removal rate of formaldehyde achieved a maximum of 0,407 kg m-3 d-1, when the applied rate in the system was 0,411 kg m-3 d-1. This fact happened when the concentration of aldehyde in the influent was 410,8 mg L-1. The maximum concentration verified of formaldehyde in the effluent of system was 5,8 mg L-1, with an average of 1,9 ± 1,4 mg L-1. The process of nitrification has been inhibited in the Biological Aerated Filter from 50 mg L-1 of formaldehyde present in the influent. The proposed system was adequate to the treatment of domestic wastewater plus formaldehyde because in all concentration of aldehyde applied (0 a 410,8 mg L-1) its performance was kept stable, mainly in relation to COD removal and formaldehyde itself. Key words: Formaldehyde, combined system anaerobic/aerobic, anaerobic filter, biological aerated filter, nitrification, domestic wastewater / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

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