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Evaluation of Digital PCR (dPCR) for the Quantification of Soil Nitrogen Turnover Bacteria in Wetland Mesocosms in Response to Season, Fertilization, and Plant Species RichnessShah, Parita Raj 11 February 2019 (has links)
Excess nutrients from nonpoint sources are an ongoing problem that is expected to worsen as population and fertilizer usage rise. Conventional centralized treatment systems are not well suited to address nonpoint source pollution. More distributed best management practices (BMPs) like constructed wetlands are a promising alternative and have been widely implemented in the US since the 1970's. Constructed wetlands are multi-functional systems that can effectively store and transform harmful contaminants using primarily natural processes. However, the removal of pollutants like nitrogen by wetlands is highly variable, likely due to a combination of factors such as plant species-specific assimilation behavior, the effects of plant communities on microbial diversity and function, and variable nitrogen inputs. In this study, the effect of plant species richness (i.e., number of plant species in a system) and seasonal nutrient loading (i.e., nitrogen fertilization) on the microbial community responsible for regulating nitrogen turnover in wetland mesocosm soils was investigated. The chip-based QuantStudio 3D digital PCR (QS3D dPCR) system was used to quantify ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), comammox, anammox, and denitrifiers. Principal component analysis (PCA) was used to identify dominant patterns in the microbial community and nitrogen species. Resampling-based analysis of variance (ANOVA) was used to assess statistical significance of any observed differences caused by nitrogen fertilization or plant species richness. Results indicated that fertilization or season, which was convolved with fertilization, was the dominant factor influencing the microbial community in the study environment (27% variance explained), as indicated by the disparate clustering of fall (fertilized) and spring (unfertilized) samples about principal component 1 (fall: negative PC1, spring: positive PC1). Because unplanted unfertilized controls sampled in November clustered within the season in which they were collected rather than with other unfertilized samples collected in May, season may have influenced microbial community shifts more than fertilization for unplanted systems. This finding should be interpreted cautiously, however, given the small number of unplanted unfertilized controls (N = 2) and the absence of similar controls in the planted systems. The most abundant bacterial groups detected in May (November) were AOB, nirK, anammox, and Nitrospira spp. NOB (AOB, anammox, Nitrospira spp. NOB, and nosZ). The effects of plant species richness were more nuanced, with greater richness significantly impacting the abundance of only a subset of bacterial groups (i.e., the nitrifying bacteria AOB, Nitrospira spp. NOB, and comammox, but not the denitrifying bacteria). Different relationships between richness and microbial abundance were observed in different seasonal nutrient loadings (i.e., interaction effects between richness and fertilization were detected for some bacterial groups). / MS / As global population continues to rise, fertilizer application is becoming more commonplace in order to meet increasing agricultural demand. Fertilizers supply nutrients like nitrogen that, in excess, can negatively affect water quality. Since conventional treatment systems are largely impractical to control such diffuse, nonpoint sources of pollution, more distributed best management practices (BMPs) like constructed wetlands are a promising alternative. Several important nitrogen transformations occur within wetlands, of which soil microbial communities have a significant influence over. For instance, nitrifying bacteria can transform ammonia into nitrate and denitrifying bacteria can transform nitrate into atmospheric nitrogen. Constructed wetlands are designed to mimic these complex, dynamic processes, and can be manipulated for more effective nitrogen pollution control. However, the removal of pollutants like nitrogen by wetlands is highly variable, likely due to a combination of factors such as plant species-specific assimilation behavior, the effects of plant communities on microbial diversity and function, and variable nitrogen inputs. In this study, the effects of plant species richness (i.e., number of plant species in a system) and seasonal nutrient loading (i.e., nitrogen fertilization) on several types of nitrifying and denitrifying bacteria in wetland mesocosm soils were investigated. Digital polymerase chain reaction (dPCR) was used to quantify bacterial abundance. Principal component analysis (PCA) was used to identify dominant patterns within the data and resampling-based analysis of variance (ANOVA) was used to assess statistical significance of any observed differences caused by fertilization, season, and/or plant species richness. Results indicated that fertilization or season, which was convolved with fertilization, wasthe dominant factor influencing the microbial community in the study environment. The effects of plant species richness were more nuanced, with greater richness significantly impacting the abundance of only a subset of bacterial groups (i.e., the nitrifying bacteria AOB, Nitrospira spp. NOB, and comammox, but not the denitrifying bacteria).
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Mechanistic Understanding of the NOB Suppression by Free Ammonia Inhibition in Continuous Flow Aerobic Granulation BioreactorsKent, Timothy Robert 15 February 2019 (has links)
A partial nitritation-anammox continuous flow reactor (CFR) was operated for eight months demonstrating that a mixture of large anammox-supported aerobic granules (ASAGs) and small conventional aerobic granules (CAGs) can be maintained stably for extended periods of time. The influent NH4+ was kept at 50 - 60 mg N L-1 to verify that the upper range of total ammonia nitrogen (TAN) for domestic wastewater can supply an inhibitory level of free ammonia (FA) for nitrite oxidizing bacteria (NOB) suppression in CFRs at pH around 7.8. The ammonia oxidizing bacteria (AOB):NOB activity ratio was determined for a series of granule sizes to understand the impact of mass diffusion limitation on the FA inhibition of NOB. When dissolved oxygen (DO) limitation is the only mechanism for NOB suppression, the AOB:NOB ratio was usually found in previous studies to increase with the granule size. However, the trend is reversed when FA has an inhibitory effect on NOB, as was observed in this study. The decrease in AOB:NOB ratio indicates that the resistance to the diffusion of FA along the granule radius limited its ability to inhibit NOB. This means smaller granules, e.g. diameter < 150 microns, are preferred for nitrite accumulation when high FA is present, e.g. in the partial nitritation-anammox process. The trend was further verified by observing the increase in the apparent inhibition coefficient, KI,FAapp, as granule size increased. This study for the first time quantified the effect of diffusion limitation on the KI,FAapp of NOB in granules and biofilms. A mathematical model was then utilized to interpret the observed suppression of NOB. The model predicted that NOB suppression was only complete at the granule surface. The NOB that did survive in larger granules was forced to dwell within the granule interior, where the FA concentration was lower than that in the bulk solution. This means FA inhibition can be taken advantage of as an effective means for NOB suppression in small granules and thin biofilms. Further, FA and DO were found to be both required for the stratification of AOB and NOB in partial nitritation-anammox CFRs. The structural stratification commonly observed in granules is then concluded to be a consequence but not a cause of the NOB suppression. / MS / A partial nitritation-anammox continuous flow reactor (CFR) was operated for eight months demonstrating that granular sludge can be maintained stably for extended periods of time. In this approach, NH3 is only partially converted to NO2 - (partial nitritation), and the conversion to NO3 - is prevented by the suppression of nitrite oxidizing bacteria (NOB). NH3 and NO2 - are then utilized by anammox bacteria to create N2 gas. The influent NH4 + fed to the reactor was kept at 50 to 60 mg N L-1 to verify that the upper range of total ammonia nitrogen (TAN) for domestic wastewater can supply a sufficiently high level of free ammonia (FA) to inhibit NOB growth in CFRs at a pH around 7.8. It is expected that the penetration of a substrate into granule sludge will experience diffusional resistance as it moves from water to denser solid material and is consumed by bacteria. The ammonia oxidizing bacteria (AOB):NOB activity ratio was determined for a series of granule sizes to understand the impact of mass diffusion limitation on the FA inhibition of NOB. When dissolved oxygen (DO) limitation is the only mechanism for NOB suppression, the AOB:NOB ratio was usually found in previous studies to increase with the granule size. However, the trend is reversed when FA has an inhibitory effect on NOB, as was observed in this study. The decrease in AOB:NOB ratio indicates that the resistance to the diffusion of FA, which increases with increasing granule size, along the granule radius limited its ability to inhibit NOB. This means smaller granules, e.g. diameter < 150 µm, are preferred for NO2 - accumulation when high FA is present. The trend was further verified by observing the increase in the apparent inhibition coefficient, KI,FAapp, as granule size increased. This coefficient quantifies the effectiveness of an inhibitor, with larger values indicating weaker inhibition. This study for the first time quantified the effect of diffusion limitation on the KI,FAapp of NOB in granules and biofilms. A mathematical model was then utilized to interpret the observed suppression of NOB. The model predicted that NOB suppression was only complete at the granule surface. The NOB that did survive in larger granules was forced to dwell within the granule interior, where the FA concentration was lower than that in the bulk solution. This means FA inhibition can be taken advantage of as an effective means for NOB suppression in small granules and thin biofilms. Further, FA and DO were found to be both required for the stratification of a layer of AOB at the surface over a layer of NOB in partial nitritation-anammox CFRs. The structural stratification commonly observed in granules is then concluded to be a consequence but not a cause of the NOB suppression.
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Remoção de nitrogênio via processo de desamonificação utilizando-se diferentes configurações de reatores / Nitrogen removal via deammonification process using different reactors configurationsChini, Angélica 13 February 2015 (has links)
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Previous issue date: 2015-02-13 / Nitrogen is an essential nutrient for the survival of living organisms, and although abundant as a gas (N₂), it is largely inaccessible in this form to most beings. Nitrogen only becomes accessible when converted into, for example, ammonia, nitrite and nitrate. These substances can be found in high concentrations in effluents, such as swine wastewater, generating a high concentration of nutrients, which may cause damage to the environment and to public health. Biological processes are widely used to remove high nutrients loads. In this context, anammox, partial nitritation (PN) and their combination, as deammonification, are being studied for nitrogen removal. The deammonification consists in ammonia oxidation by PN and that generates substrate to anammox activity; therefore, it must have partial nitrification control to prevent nitrite accumulation. The nitrite concentration in the reactor can inhibit the anammox process, which can be controlled with different strategies, such as aeration and reactor configuration. Considering this, the present study aimed to evaluate two reactors configurations suspended and expanded sludge, for reactor configuration evaluation on deammonification process. For this, two up flow reactors were used with intermittent feeding and aeration at 30 min cycles (15 min on/ 15 min off), one with suspended and the other with expanded bed. These possess working volume of 1 L, 55 g (w/v) of biofilm plastic carrier, the temperature was maintained at 25 °C, HRT 9 h, circulation input flow rate of 2.70 L.d⁻¹ and recirculation flow rate was 2.5 times the input and it was fed with synthetic medium. It was possible to establish deammonification process in the two reactors and the experiments were carried out: phase I and III were unstable (air flow rate of 30 mL.min⁻¹.L⁻¹) and phase II was stable (air flow rate of 20 mL.min⁻¹.L⁻¹). Thus, in the tested process conditions, it was inferred that the ideal air flow rate was of 20 mL.min⁻¹.L⁻¹. The expanded biomass reactor configuration achieved better nitrogen removal efficiencies, being 1.23 more efficient than suspended bed, thus being considered the best option for the process under study. In the anammox and nitrifying quantification, there were no significant changes in the suspended bed reactor, only nitrifying growth in phase III. For the expanded bed reactor, anammox bacteria increased in phase II. The results showed that the expanded bed reactor presented a performance 23.06% more efficient than the suspended bed reactor. / O nitrogênio é um dos nutrientes essenciais para a sobrevivência dos organismos vivos e, embora abundante como gás (N₂), é em grande parte inacessível nesta forma à maioria dos organismos. O nitrogênio só se torna acessível quando convertido em, por exemplo, amônia, nitrito e nitrato. Substâncias essas que são encontradas em elevadas concentrações em efluentes, como os da suinocultura, gerando uma elevada concentração de nutrientes,que podem causar danos ao meio ambiente e à saúde pública. Para a remoção de elevadas cargas de nutrientes, os processos biológicos são amplamente utilizados. Assim, os processos anammox, nitritação parcial e seus sistemas combinados, como a desamonificação, estão sendo estudados para a remoção do nitrogênio. A desamonificação consiste na oxidação da amônia pela nitritação parcial (NP), gerando substrato para as bactérias com atividade anammox. Por isso, é necessário que ocorra controle rigoroso da NP a fim de evitar acúmulo de nitrito. O controle da produção de nitrito, a qual pode inibir as bactérias com atividade anammox,pode ser de várias formas, como, por exemplo, estratégias de aeração e configuração de reatores. Considerando estes aspectos, propõe-se estudar duas configurações de reatores, biomassa suspensa e biomassa expandida, com o intuito de avaliar a influência destas configurações em relação ao processo de desamonificação. Para isto, foram utilizados dois reatores de fluxo ascendente, com alimentação e aeração intermitente em ciclos de 30 min (sendo alimentação e aeração ligadas por 15 min e desligadas por 15 min), um com leito suspenso e outro expandido. Reatores com volume útil de 1L e 55 g (v/v) de meio suporte, temperatura mantida em 25 °C, TRH de 9 h, vazão de alimentação de 2,70 L.d⁻¹ e a de recirculação foi 2,5 vezes a de entrada. Os reatores foram alimentados com meio de cultura sintético contendo nitrogênio amoniacal total na faixa de 300 mgN.L⁻¹. A partir disso, foi possível estabelecer o processo de desamonificação nos dois reatores com vazões de ar de 20 e 30 mL.min⁻¹.L⁻¹, em três diferentes fases. As fases I e III foram instáveis (vazão de ar de 30 mL.min⁻¹.L⁻¹), ao passo que a fase II foi estável (vazão de ar de 20 mL.min⁻¹.L⁻¹). Dessa maneira, nas condições de processo testadas, inferiu-se que a vazão de ar de 20 mL.min⁻¹.L⁻¹ é a ideal. A configuração de reator de biomassa expandida obteve melhores resultados na remoção de nitrogênio, tendo 1,23 vezes maior eficiência do que o de biomassa suspensa. Assim sendo, o reator de leito expandido se mostrou a melhor opção para o processo estudado. Já na quantificação de biomassa anammox e nitrificante, não houve alterações significativas no reator de leito suspenso, somente crescimento de bactéria nitrificante na fase III. O reator de leito expandido, além disto, também apresentou crescimento de bactérias com atividade anammox na fase II. Os resultados evidenciaram que o reator de leito expandido teve um desempenho 23,06% superior ao de leito suspenso
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Remoção de nitrogênio via processo de desamonificação utilizando-se diferentes configurações de reatores / Nitrogen removal via deammonification process using different reactors configurationsChini, Angélica 13 February 2015 (has links)
Made available in DSpace on 2017-07-10T19:23:57Z (GMT). No. of bitstreams: 1
Angelica _Chini.pdf: 1719142 bytes, checksum: cacffbf4d6a7bd7dd87a559756ed1238 (MD5)
Previous issue date: 2015-02-13 / Nitrogen is an essential nutrient for the survival of living organisms, and although abundant as a gas (N₂), it is largely inaccessible in this form to most beings. Nitrogen only becomes accessible when converted into, for example, ammonia, nitrite and nitrate. These substances can be found in high concentrations in effluents, such as swine wastewater, generating a high concentration of nutrients, which may cause damage to the environment and to public health. Biological processes are widely used to remove high nutrients loads. In this context, anammox, partial nitritation (PN) and their combination, as deammonification, are being studied for nitrogen removal. The deammonification consists in ammonia oxidation by PN and that generates substrate to anammox activity; therefore, it must have partial nitrification control to prevent nitrite accumulation. The nitrite concentration in the reactor can inhibit the anammox process, which can be controlled with different strategies, such as aeration and reactor configuration. Considering this, the present study aimed to evaluate two reactors configurations suspended and expanded sludge, for reactor configuration evaluation on deammonification process. For this, two up flow reactors were used with intermittent feeding and aeration at 30 min cycles (15 min on/ 15 min off), one with suspended and the other with expanded bed. These possess working volume of 1 L, 55 g (w/v) of biofilm plastic carrier, the temperature was maintained at 25 °C, HRT 9 h, circulation input flow rate of 2.70 L.d⁻¹ and recirculation flow rate was 2.5 times the input and it was fed with synthetic medium. It was possible to establish deammonification process in the two reactors and the experiments were carried out: phase I and III were unstable (air flow rate of 30 mL.min⁻¹.L⁻¹) and phase II was stable (air flow rate of 20 mL.min⁻¹.L⁻¹). Thus, in the tested process conditions, it was inferred that the ideal air flow rate was of 20 mL.min⁻¹.L⁻¹. The expanded biomass reactor configuration achieved better nitrogen removal efficiencies, being 1.23 more efficient than suspended bed, thus being considered the best option for the process under study. In the anammox and nitrifying quantification, there were no significant changes in the suspended bed reactor, only nitrifying growth in phase III. For the expanded bed reactor, anammox bacteria increased in phase II. The results showed that the expanded bed reactor presented a performance 23.06% more efficient than the suspended bed reactor. / O nitrogênio é um dos nutrientes essenciais para a sobrevivência dos organismos vivos e, embora abundante como gás (N₂), é em grande parte inacessível nesta forma à maioria dos organismos. O nitrogênio só se torna acessível quando convertido em, por exemplo, amônia, nitrito e nitrato. Substâncias essas que são encontradas em elevadas concentrações em efluentes, como os da suinocultura, gerando uma elevada concentração de nutrientes,que podem causar danos ao meio ambiente e à saúde pública. Para a remoção de elevadas cargas de nutrientes, os processos biológicos são amplamente utilizados. Assim, os processos anammox, nitritação parcial e seus sistemas combinados, como a desamonificação, estão sendo estudados para a remoção do nitrogênio. A desamonificação consiste na oxidação da amônia pela nitritação parcial (NP), gerando substrato para as bactérias com atividade anammox. Por isso, é necessário que ocorra controle rigoroso da NP a fim de evitar acúmulo de nitrito. O controle da produção de nitrito, a qual pode inibir as bactérias com atividade anammox,pode ser de várias formas, como, por exemplo, estratégias de aeração e configuração de reatores. Considerando estes aspectos, propõe-se estudar duas configurações de reatores, biomassa suspensa e biomassa expandida, com o intuito de avaliar a influência destas configurações em relação ao processo de desamonificação. Para isto, foram utilizados dois reatores de fluxo ascendente, com alimentação e aeração intermitente em ciclos de 30 min (sendo alimentação e aeração ligadas por 15 min e desligadas por 15 min), um com leito suspenso e outro expandido. Reatores com volume útil de 1L e 55 g (v/v) de meio suporte, temperatura mantida em 25 °C, TRH de 9 h, vazão de alimentação de 2,70 L.d⁻¹ e a de recirculação foi 2,5 vezes a de entrada. Os reatores foram alimentados com meio de cultura sintético contendo nitrogênio amoniacal total na faixa de 300 mgN.L⁻¹. A partir disso, foi possível estabelecer o processo de desamonificação nos dois reatores com vazões de ar de 20 e 30 mL.min⁻¹.L⁻¹, em três diferentes fases. As fases I e III foram instáveis (vazão de ar de 30 mL.min⁻¹.L⁻¹), ao passo que a fase II foi estável (vazão de ar de 20 mL.min⁻¹.L⁻¹). Dessa maneira, nas condições de processo testadas, inferiu-se que a vazão de ar de 20 mL.min⁻¹.L⁻¹ é a ideal. A configuração de reator de biomassa expandida obteve melhores resultados na remoção de nitrogênio, tendo 1,23 vezes maior eficiência do que o de biomassa suspensa. Assim sendo, o reator de leito expandido se mostrou a melhor opção para o processo estudado. Já na quantificação de biomassa anammox e nitrificante, não houve alterações significativas no reator de leito suspenso, somente crescimento de bactéria nitrificante na fase III. O reator de leito expandido, além disto, também apresentou crescimento de bactérias com atividade anammox na fase II. Os resultados evidenciaram que o reator de leito expandido teve um desempenho 23,06% superior ao de leito suspenso
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Treatment of mature urban landfill leachates by anammox processRuscalleda Beylier, Maël 17 February 2012 (has links)
This thesis results from the collaborative projects between the LEQUIA-UdG group and Cespa (a company in charge of several landfill sites in Spain). The aim of the work was the development of a suitable alternative treatment for nitrogen removal from mature landfill leachates. The thesis presents the application of the anammox (anaerobic ammonium oxidation process) process to treat ammonium rich leachates as the second step of the PANAMMOX® process. The work deals with preliminary studies about the characteristics of the anammox process in a SBR, with special focus on the response of the biomass to nitrite exposure. The application of the anammox process with leachate was first studied in a lab-scale reactor, to test the effect of the leachate matrix on anammox biomass and its progressive adaptation. Finally, a start-up strategy is developed and applied for the successful start-up of a 400L anammox SBR in less than 6 months. / Aquesta tesi és fruit de la col•laboració entre el grup LEQUIA-UdG i Cespa. L'objectiu del treball va ser el desenvolupament d'un tractament alternatiu per a l'eliminació biològica de nitrogen dels lixiviats madurs d'abocador. La tesi presenta l'aplicació del procés anammox (anaerobic ammonium oxidation) per tractar elevades càrregues de nitrogen en el segon pas del procés PANAMMOX ®. El treball inclou estudis preliminars sobre les característiques del procés de anammox en un SBR, amb especial atenció a la resposta de la biomassa a l'exposició de nitrit. L'aplicació del procés anammox amb lixiviat es va estudiar inicialment en un reactor a escala de laboratori, per provar l'efecte de la matriu del lixiviat sobre la biomassa anammox i la seva adaptació progressiva. Finalment, es va desenvolupar una estratègia de posada en marxa que va ser aplicada amb èxit per a la posada en marxa d'un SBR anammox de 400L en menys de 6 mesos.
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Influência da relação carbono/nitrogênio e da fonte de carbono no processo de nitrificação desnitrificação simultânea em reator de leito estruturado / Influence of COD/N ratio and carbon source on the simultaneous nitrification and denitrification in a structured-bed reactorSantos, Carla Eloísa Diniz dos 25 March 2014 (has links)
Este trabalho buscou avaliar a influência da relação C/N e da fonte de carbono no processo de nitrificação e desnitrificação simultâneas em reator de fluxo contínuo e leito fixo estruturado. Foi utilizado um reator vertical de acrílico, com volume total de 11,0 L e volume útil de 5,5 L, com hastes cilíndricas verticais de espuma de poliuretano como suporte para a biomassa. O sistema foi operado com TDH de 11,2±0,6 horas, aeração intermitente (2 horas com aeração e 1 hora sem aeração) e razão de recirculação de efluente igual a 5. A carga carbonácea afluente foi mantida constante (1,07 kg DQO.m-3.dia-1), ao longo de todo o período experimental, sendo as relações C/N testadas (9,7±1; 7,6±1; 2,9±1 e 2,9±0,4) obtidas a partir da variação na carga nitrogenada aplicada. Duas fontes orgânicas foram avaliadas: sacarose e peptona de carne. A eficiência média de remoção de DQO manteve-se acima de 90%. A eficiência máxima de remoção de N-total (84,6±10,1%) foi obtida para relação C/N de 2,9±1, com concentrações efluentes médias de NTK e N-NH4 de 5,9 e 4,3 mg.L-1, respectivamente. A análise estatística da eficiência de remoção de N-total confirmou que a fonte de carbono não exerceu influência sobre os processos de remoção. A obtenção de eficiências de desnitrificação superiores às calculadas estequiometricamente, em função da fonte de carbono, indicou a ocorrência de possíveis vias complementares para remoção de nitrogênio, como o processo anammox. As velocidades de nitrificação e desnitrificação obtidas nos ensaios cinéticos foram similares para as duas fontes de carbono e para as relações C/N estudadas e da mesma ordem de grandeza das apresentadas na literatura, reforçando a ideia de que a configuração de reator utilizada, aliada às adequadas condições operacionais, permitiu a remoção concomitante de matéria carbonácea e nitrogenada. / This study aimed to evaluate the influence of COD/N ratio and organic source on the simultaneous nitrification and denitrification (SND) in an up-flow structured-bed reactor. The reactor was made of acrylic with a total volume of 11 L and a working volume of 5.5 L and filled with cylinders of polyurethane foam as support for biomass growth. The system was continuously operated with an HRT of 11.2±0.6 h, intermittent aeration (2h with aeration and 1h without aerationd) and a liquid recycle ratio equal to 5. The organic load rate was constant (1.07 kg COD.m-3d-1) during the entire experiment. The COD/N ratios (9.7±1; 7.6±1; 2.9±1 and 2.9±0,4) were obtained from the variation of nitrogen load rate. Two organic sources were evaluated: sucrose and meat peptone. The average COD removal efficiency was above 90%. The maximum total nitrogen removal efficiency was 84.6±10.1%, with average TKN and NH4+-N effluent concentrations of 5.9 and 4.3 mg.L-1, respectively. Statistical analysis of total nitrogen removal efficiency confirmed that the carbon source did not influence over the removal processes. The denitrification efficiencies higher than the stoichiometrically calculated in function of the carbon source, indicated the occurrence of possible paths for nitrogen removal of nitrogen as anammox process. The nitrification and denitrification rates obtained in kinetic experiments were similar for the two sources of carbon and all C/N ratio studied at the same order of magnitude in relation to those reported in the literature, enhancing that the reactor configuration tested combined with the proper operational conditions allowed the organic matter and nitrogen removal simultaneously.
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Influência da relação carbono/nitrogênio e da fonte de carbono no processo de nitrificação desnitrificação simultânea em reator de leito estruturado / Influence of COD/N ratio and carbon source on the simultaneous nitrification and denitrification in a structured-bed reactorCarla Eloísa Diniz dos Santos 25 March 2014 (has links)
Este trabalho buscou avaliar a influência da relação C/N e da fonte de carbono no processo de nitrificação e desnitrificação simultâneas em reator de fluxo contínuo e leito fixo estruturado. Foi utilizado um reator vertical de acrílico, com volume total de 11,0 L e volume útil de 5,5 L, com hastes cilíndricas verticais de espuma de poliuretano como suporte para a biomassa. O sistema foi operado com TDH de 11,2±0,6 horas, aeração intermitente (2 horas com aeração e 1 hora sem aeração) e razão de recirculação de efluente igual a 5. A carga carbonácea afluente foi mantida constante (1,07 kg DQO.m-3.dia-1), ao longo de todo o período experimental, sendo as relações C/N testadas (9,7±1; 7,6±1; 2,9±1 e 2,9±0,4) obtidas a partir da variação na carga nitrogenada aplicada. Duas fontes orgânicas foram avaliadas: sacarose e peptona de carne. A eficiência média de remoção de DQO manteve-se acima de 90%. A eficiência máxima de remoção de N-total (84,6±10,1%) foi obtida para relação C/N de 2,9±1, com concentrações efluentes médias de NTK e N-NH4 de 5,9 e 4,3 mg.L-1, respectivamente. A análise estatística da eficiência de remoção de N-total confirmou que a fonte de carbono não exerceu influência sobre os processos de remoção. A obtenção de eficiências de desnitrificação superiores às calculadas estequiometricamente, em função da fonte de carbono, indicou a ocorrência de possíveis vias complementares para remoção de nitrogênio, como o processo anammox. As velocidades de nitrificação e desnitrificação obtidas nos ensaios cinéticos foram similares para as duas fontes de carbono e para as relações C/N estudadas e da mesma ordem de grandeza das apresentadas na literatura, reforçando a ideia de que a configuração de reator utilizada, aliada às adequadas condições operacionais, permitiu a remoção concomitante de matéria carbonácea e nitrogenada. / This study aimed to evaluate the influence of COD/N ratio and organic source on the simultaneous nitrification and denitrification (SND) in an up-flow structured-bed reactor. The reactor was made of acrylic with a total volume of 11 L and a working volume of 5.5 L and filled with cylinders of polyurethane foam as support for biomass growth. The system was continuously operated with an HRT of 11.2±0.6 h, intermittent aeration (2h with aeration and 1h without aerationd) and a liquid recycle ratio equal to 5. The organic load rate was constant (1.07 kg COD.m-3d-1) during the entire experiment. The COD/N ratios (9.7±1; 7.6±1; 2.9±1 and 2.9±0,4) were obtained from the variation of nitrogen load rate. Two organic sources were evaluated: sucrose and meat peptone. The average COD removal efficiency was above 90%. The maximum total nitrogen removal efficiency was 84.6±10.1%, with average TKN and NH4+-N effluent concentrations of 5.9 and 4.3 mg.L-1, respectively. Statistical analysis of total nitrogen removal efficiency confirmed that the carbon source did not influence over the removal processes. The denitrification efficiencies higher than the stoichiometrically calculated in function of the carbon source, indicated the occurrence of possible paths for nitrogen removal of nitrogen as anammox process. The nitrification and denitrification rates obtained in kinetic experiments were similar for the two sources of carbon and all C/N ratio studied at the same order of magnitude in relation to those reported in the literature, enhancing that the reactor configuration tested combined with the proper operational conditions allowed the organic matter and nitrogen removal simultaneously.
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Evaluation of microbiological activity during the deammonification process for nitrogen removal.Wójcik, Weronika January 2011 (has links)
This master thesis is based on own studies. A four-month study was performed at Hammarby Sjostad Research Station, which is located in Stockholm. One-stage deammonification process was evaluated in two different system configurations in pilot plant scale. The theoretical background for this thesis works is presented in the first part and where is presented negative impacts of nitrogen compounds in environment and requirements for purified wastewater in European Union (Sweden and Poland). In the next part of the thesis the nitrogen cycle is described and with focus on biological reactions for nitrogen removal. Especially, nitrification/denitrification and anammox processes are described with special focus on parameters affecting the anammox process performance and its advantages and disadvantages of using this process. Experimental results from the four-month study and evaluation of the microbial activity are described in the last part.
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Nitrogen Removal in Drinking Water Treatment - A Combination of Zeolite Sorption and the Anammox-ProcessEberle, Stephan Martin 28 July 2023 (has links)
Wasserknappheit und verminderte Wasserqualität sind Folgen des Klimawandels und zu-nehmender menschlichen Aktivitäten in der Landwirtschaft. Um den weltweiten Nahrungsmittelbedarf zu decken, ist der Einsatz von Stickstoffdüngern (hauptsächlich in Form von NH4+) notwendig, um die Qualität und den Ertrag von Nutzpflanzen zu steigern. Eine wachsende Weltbevölkerung macht einen verstärkten Einsatz von Stickstoffdüngern in der Landwirtschaft erforderlich, was zu einem erhöhten Eintrag von reaktivem Stickstoff in den Boden und das Grundwasser führt. Zusammen mit Abwassereinleitungen aus Haus-halten und Industrie in die Umwelt ist die Landwirtschaft Schätzungen zufolge der Hauptverschmutzer von Trinkwasserquellen. Neben Vermeidungs- und Verminderungsstrategien ist die Entwicklung innovativer Technologien zur Entfernung von Stickstoffverbindungen aus Trinkwasserquellen ein vielversprechender Ansatz zur Lösung dieses Problems.
Diese Arbeit zeigt die Machbarkeit eines kombinierten Zeolith- und Anammox-Verfahrens zur Entfernung von Stickstoffverbindungen in einer grundwasserähnlichen Matrix für die Trinkwasseraufbereitung auf. Unter Verwendung von natürlichen Zeolithe (Klinoptilolith) als Sorbentien (für NH4+) und als Biofilmträger (für Anammox Bakterien) in einem Festbett-Biofilter wurde ein hocheffizienter, kostensparender, kompakter und wartungsarmer Prozess für dezentrale Anwendungen demonstriert. Darüber hinaus wurden in einer technischen und wirtschaftlichen Bewertung die Chancen und Risiken dieses Verfahrens für die Trinkwasseraufbereitung aufgezeigt.
Der Einfluss von Schlüsselparametern auf die Sorption von NH4+ an natürlichen Zeolithe ergab eine hohe NH4+-Selektivität (NH4+ > K+ > Na+ > Mg2+ > Ca2+), hohe Sorptionskapazitäten (bis zu 21.3 mg(NH4+)/g) und hohe Entfernungsleistungen (bis zu 99 %). Untersuchungen in Multisorbat- und natürlichen Wassermatrices ergaben, dass die Konzentrationen von K+ und gelöstem organischem Kohlenstoff (DOC) den größten Einfluss auf die Sorption von NH4+ haben. Die Gleichgewichtsbeladung wurde dabei um bis zu 8% verringert. Der Einfluss von Anionen kann in Grundwasser typischen Konzentrationen bei pH-Werten oberhalb des pHPZC (Point of Zero Charge) vernachlässigt werden. Der pHPZC konnte zwischen pH 6.24 und pH 6.47 bestimmt werden. Zwischen pH 5 und pH 7 wurde eine maximale NH4+-Entfernungsleistung festgestellt, wohingegen aufgrund eines erhöhten Anteils an nicht sorbierbarem NH3(aq) ab pH ≥ 8 die Entfernungsleistung stark abnahm. Bei einer NH4+-Konzentration von 12.8 mg/L konnte der zugrundeliegende Sorptionsmechanismus auf den Ionenaustausch zurückgeführt werden (R² = 0,997). NH4+ beladene Zeolithe ließen sich am besten mit einer K+-Salzlösung regenerieren.
Experimentell ermittelte Durchbruchskurven und eine zweifaktorielle Varianzanalyse bestätigten einen starken Einfluss der K+- und DOC-Konzentrationen auf den Durchbruch von NH4+ in natürlichen Wassermatrices. Bei einem Durchbruch von 50% wurde mit dem Einsatz von Elbewasser die Anzahl der behandelten Bettvolumina (BVs) um 69% reduziert. Darüber hinaus wurden die NH4+-Durchbruchskurven mit und ohne den Einfluss von K+ in Reinstwasser sowohl mit dem Linear Driving Force (LDF)- als auch mit dem Thomas-Modell erfolgreich modelliert und durch experimentelle Daten validiert. Die Verwendung solcher Modelle ist ein vielversprechendes Instrument, um zeitaufwändige und umfangreiche Untersuchungen im Labor und im Feld zu reduzieren.
Um das Anammox-Verfahren erfolgreich etablieren zu können ist ein stabiler Betrieb der partiellen Nitritation (PN) zur Regulierung des erforderlichen stöchiometrischen NO2-/NH4+-Verhältnisses (1.32:1) entscheidend. Vorläufige Untersuchungen mit einem Fest-bett-Biofilter und einem Sequencing-Batch-Reaktor (SBR) zeigten, dass die folgenden Faktoren bei der Anwendung einer PN berücksichtigt werden müssen: (1) komplexe Wechselbeziehungen zwischen mikrobiellen Gemeinschaften mit unterschiedlichen Substratanforderungen, synergetische/kompetitive Wechselwirkungen, inhibierende Prozesse, und Stoffwechselprodukte; und (2) die Notwendigkeit, verschiedene Inhibierungsstrategien zu etablieren, um die Aktivität NO2- oxidierender Bakterien (NOB) zu unterdrücken. Es ist entscheidend, einen geschichteten und stabilen Biofilm zu etablieren, bevor eine PN unter Grundwasserbedingungen mit erhöhten Temperaturen und hohen NH4+-Konzentrationen eingesetzt wird.
Das kombinierte Zeolith- und Anammox-Verfahren wurde in einem sequentiellen Zeolith-Anammox-Biofilter untersucht. Trotz weitaus niedrigerer Substratkonzentrationen und einer 8-fach höheren Filtergeschwindigkeit wurden vergleichbare Entfernungsleistungen für NH4+ (86%) und NO2- (76%) wie mit ähnlichen Zeolith- Anammox-Systemen für die Abwasseraufbereitung ermittelt. Die Entfernungsleistungen für NH4+ und NO2- konnten durch einen Vergleich ihrer Halbwertszeiten mit der effektiven hydraulischen Aufenthaltsdauer im Biofilter bestätigt werden. Die Entfernung von NH4+ erfolgte aufgrund der Sorption über Zeolithe und des Anammox-Stoffwechsel wesentlich schneller als für NO2-, deren Entfernung lediglich auf den Anammox-Stoffwechsel zurückführbar ist. Sowohl die ermittelten Halbwertszeiten als auch das von der Filterhöhe abhängige NO2-/NH4+-Verhältnis konnte eine schnellere NH4+-Entfernung bestätigen. Die Grenzwerte für NO2- der Weltgesundheitsorganisation (WHO: 3 mg/L) und der Vereinigten Staaten von Amerika (USA: 3.2 mg/L)) wurden bei Filtergeschwindigkeiten von 0.032 m/h und 0.043 m/h eingehalten. Bei 0.032 m/h und 0.043 m/h wurden die NH4+-Grenzwerte für China (0.6 mg/L) und Deutschland (0.5 mg/L) leicht überschritten. Durch eine Korrelation der NH4+- und NO2--Entfernung mit der elektrischen Leitfähigkeit konnte darüber hinaus bei allen untersuchten Filtergeschwindigkeiten ein vereinfachtes Verfahren zur Prozessüberwachung demonstriert werden.
Eine technisch-wirtschaftliche Bewertung ergab die höchste technische Wertigkeit (X) für das Ionenaustauschverfahren mit Zeolithe (X: 0.79), gefolgt vom Nitrifikationsverfahren (X: 0.68) und dem Verfahren der partiellen Nitritation/Anammox (PN/A) (X: 0.52). Das Ionen-austauschverfahren zeichnet sich dabei vor allem durch eine einfache Handhabung und Anpassung hinsichtlich schwankender NH4+-Konzentrationen im Zulauf sowie eine hohe Betriebssicherheit aus. Dagegen sind vergleichsweise lange Etablierungszeiten, eine un-sichere Betriebssicherheit und eine hohe verfahrenstechnische Komplexität für das PN/A-Verfahren zu erwarten.
Die Gesamtkosten jedes Verfahrens wurden unter Berücksichtigung der Anlagengröße, lokaler Strompreise und unterschiedlicher NH4+-Konzentrationen im Zulauf über einen Zeitraum von 20 Jahren berechnet.
Auf Grundlage dieser Berechnung können die folgenden Empfehlungen für eine dezentrale Trinkwasseraufbereitung ausgesprochen werden: (1) Das Ionenaustauschverfahren kann für NH4+-Konzentrationen bis zu 21 mg/L empfohlen werden; (2) das PN/A-Verfahren wird bei höheren NH4+-Konzentrationen wirtschaftlicher; und (3) das Nitrifikationsverfahren weist ab einer NH4+-Konzentration von ≥ 14 mg/L im Zulauf eine ungünstige Wirtschaftlichkeit auf, da eine zusätzliche Denitrifikationsstufe eingeplant werden muss um den NO3- Grenzwert von 50 mg/L der WHO und von Deutschland einzuhalten. Werden die Berechnungen mit einem niedrigeren KCl-Preis wiederholt, kann das Ionenaustauschverfahren bis zu einer NH4+-Konzentration von 60 mg/L empfohlen werden. Das PN/A-Verfahren stellt bei NH4+-Konzentrationen ≥ 60 mg/L das wirtschaftlichere Verfahren dar.
Insgesamt ist das kombinierte Zeolith- und Anammox-Verfahren ein vielversprechendes Verfahren zur Entfernung von Stickstoffverbindungen in dezentralen Anwendungen für die Trinkwasseraufbereitung in Schwellen- und Entwicklungsländern des globalen Südens. Insbesondere dort, wo erhöhte Temperaturen und hohe NH4+-Konzentrationen in Trinkwasserquellen zu finden sind.:1. Introduction ................................................................................................................. 1
2. Topic and Objective of the Thesis ............................................................................. 3
3. Background and Literature Review ........................................................................... 5
3.1 General Aspects about the Global Nitrogen Cycle ............................................ 5
3.1.1 Nitrogen Reservoirs and Anthropogenic Activities ........................................... 5
3.1.2 Nitrogen Cycle in Riverbank Filtration and Groundwater ................................. 7
3.1.3 Ecological Relevance and Physiological Effects of Nitrogen Compounds ..... 10
3.2 Ammonium Removal Processes – Current State of Knowledge .................... 12
3.2.1 Distinction: Drinking Water vs. Wastewater Treatment .................................. 13
3.2.2 Zeolites: Occurrence, Characteristics and Application ................................... 17
3.2.3 Partial Nitritation and Anammox ..................................................................... 20
4. Results and Discussion ............................................................................................ 25
4.1 Publication 1: Granular Natural Zeolites: Cost-Effective Adsorbents for the
Removal of Ammonium from Drinking Water ............................................................ 25
4.2 Publication 2: Natural Zeolites for the Sorption of Ammonium: Breakthrough
Curve Evaluation and Modeling .................................................................................. 48
4.3 Preliminary Investigations to the Partial Nitritation ........................................ 66
4.3.1 Material and Methods .................................................................................... 66
4.3.2 Results and Discussion .................................................................................. 70
4.3.3 Conclusions ................................................................................................... 77
4.4 Publication 3: A Sequential Anammox Zeolite-Biofilter for the Removal of
Nitrogen Compounds from Drinking Water ............................................................... 79
4.5 Technical-Economic Evaluation ........................................................................ 99
4.5.1 Material and Methods .................................................................................... 99
4.5.2 Results and Discussion ................................................................................ 103
4.5.3 Conclusions ................................................................................................. 114
5. Summary and General Conclusions ...................................................................... 116
6. Outlook ..................................................................................................................... 119
References ..................................................................................................................... 122
List of Tables ................................................................................................................. 139
List of Figures ................................................................................................................ 141
List of Abbreviations ..................................................................................................... 144
List of Formular ............................................................................................................. 146
Appendix ........................................................................................................................ 147
A-1 Supporting Information: Section 3 .................................................................. 147
A-2 Supporting Information: Section 4 .................................................................. 149
A-2.1 Publication 1: Granular Natural Zeolite: Cost-Effective Adsorbents for the
Removal of Ammonium from Drinking Water ............................................................ 149
A-2.2 Publication 2: Natural Zeolites for the Sorption of Ammonium: Breakthrough
Evaluation and its Modeling ...................................................................................... 157
A-2.3 Preliminary Investigations to Partial Nitritation ............................................. 162
A-2.4 Publication 3: A Sequential Anammox Zeolite-Biofilter for the Removal of
Nitrogen Compounds from Drinking Water ............................................................... 168
A-2.5 Technical-Economic Evaluation ................................................................... 179
Journal Articles and Conference Contributions ......................................................... 200
Acknowledgements ....................................................................................................... 201
Declaration ..................................................................................................................... 202
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Nitrous Oxide Emissions in Reject Water Treatment at Bromma WWTP – Measurements and Measures / Lustgasbildning i Rejektvattenbehandlingen på Bromma Reningsverk – Förekomst och ÅtgärderWadefjord, Julia January 2024 (has links)
Ökade utsläpp av växthusgaser är ett stort problem idag för den pågående klimatförändringen. Lustgas (N2O) är en mycket potent växthusgas och är relaterad till kväverening vid rening av avloppsvatten. I februari 2014 ansattes en separat rejektvattenreningsprocess på Bromma reningsverk som använder ANITA™Mox med anammox bakterier som reningsteknik. Denna masteruppsats undersöker samband och korrelationer mellan kväverening och N2O utsläpp i rejektvattenreningen på Bromma reningsverk, men syftet att presentera hur Stockholm Vatten och Avfall AB kan minska sina lustgasutsläpp. En manuell profilmätning genomfördes även för att utvärdera hur processen fungerade. Fyra olika scenarion testades under åtta veckor: intermittent luftning med olika fördelning mellan luftning och icke-luftning, olika löst syrekoncentrationer, ändringar i ammoniumbelastningen samt seriekörning av processen. Den manuella profilmätningen mätte pH, konduktivitet, löst syre, nitrit- och ammoniumkoncentrationen. Dessa mätningar togs i sju olika punkter, inkluderat rejektet direkt från centrifugerna och utgående rejekt. Resultaten påvisade att vid intermittent luftning gavs de högsta utsläppen vid 60 minuter luftning och 7,5 minuter paus (1,46% N2O-N/inkommande N-tot). Lägsta utsläppen var vid samma luftningstid men 15 minuter paus (0,44% N2O-N/inkommande N-tot). Både höga och låga koncentrationer av löst syre gav ökade utsläpp. Med de högsta utsläppen vid 0,77 mg/L (0,88% N2O-N/inkommande N-tot ) och lägsta vid 0,34 mg/L (0,07% N2O-N/inkommande N-tot ). Ändringen av ammoniumbelastning (1,5 högre belastning) hav ingen signifikant skillnad gällande utsläpp, med utsläpp på 0,42–0,90% N2O-N/inkommande N-tot. Seriekörning av processen resulterade i driftproblem med höga ammoniumhalter, med utsläpp på 0,90-1,47% N2O-N/inkommande N-tot. Profilmätningarna visade på att processen är stabil och välutvecklad för att rena rejektet på kväve. Uppsatsen kan ge slutsatsen att rejektvattenreningsprocessen är komplex med många parametrar som påverkar varandra och N2O utsläppen. En ingående och bred förståelse om vad som påverkar utsläppen av lustgas är viktigt för att förstå hur utsläppen ska minskas. En positiv linjär korrelation mellan halten nitrit i processen och lustgasutsläpp kan verifieras, samt påverkan av ökade utsläpp vid både för låga och höga koncentrationer syre. Från profilmätningarna kan slutsatsen dras att det är viktigt att rengöra onlineinstrumenten regelbundet. / Greenhouse gas emissions, particularly nitrous oxide (N2O), are a significant environmental challenge linked to biological nitrogen removal in wastewater treatment. Bromma Wastewater Treatment Plant (WWTP) implemented a separate reject water treatment process in February 2017 using ANTIA™Mox with anammox bacteria. This Master's thesis investigates the relationship and correlations between nitrogen removal and N2O production in this process, aiming to assist Stockholm Vatten och Avfall AB in reducing emissions. A manual profile measurement was conducted to investigate the ongoing process. Over eight weeks, four operating strategies were tested: intermittent aeration with varying ratios between aeration and non-aeration, different dissolved oxygen (DO) concentrations, changes in ammonium load, and series configuration. Manual profile measurements of pH, conductivity, DO, nitrite, and ammonium were taken at seven points in the treatment process, including the supernatant and discharged reject. Findings indicate that intermittent aeration, particularly 60 minutes of aeration followed by a 7.5-minute pause, produced the highest N2O emissions (1.46% N2O-N/Influent N-tot load). The lowest emissions (0.44% N2O-N/Influent N-tot load) occurred with a 15-minute pause. The lowest emission (0.07% N2O-N/Influent N-tot load) was detected at 0.34 mg/L, and high DO concentrations (0.77 mg/L) had the highest emissions (0.88% N2O-N/Influent N-tot load). Variations in ammonium load (1.5 times higher) did not significantly affect emissions, averaging 0.42-0.90% N2O-N/Influent N-tot load. The series configuration faced operational challenges with elevated ammonium levels, leading to emissions of 0.90-1.47% N2O-N/Influent N-tot load. Profile measurements confirmed a stable nitrogen removal process. The study concludes that N2O emissions in reject water treatment are complex and influenced by multiple factors. A positive linear correlation was identified between nitrite concentration and N2O emissions, alongside the impact of not having too-low or too-high DO levels, which results in elevated. Regular maintenance of oxygen sensors is crucial for accurate measurements and effective N2O mitigation.
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