Dissertations / Theses on the topic 'Granuli aerobici'

Aerobic granular sludge was successfully cultivated in two lab scale Granular sludge Sequencing Batch Reactors (GSBR, A and B) to remove organic matter and nitrogen from two different petrochemical wastewaters (PWs). The aim of this study was to define the best operating conditions (i.e., shear forces, inoculum source, Ca2+ concentration, pH) to achieve complete granulation and satisfactory long-term process performance. One PW was produced by the Integrated Gasification Combined Cycle (IGCC) and characterized by high concentrations of organic matter, ammonium and toxic substances like cyanides and phenols (IGCC wastewater); the other PW, collected from the equalization tank of the refinery wastewater treatment plant, was a poorly biodegradable mixture of all the refinery discharges which contained, among the others, sulfide, hydrocarbon and low concentrations of COD and ammonium (MS18 wastewater). In order to promote granulation and biomass acclimation during reactors’ start-up, synthetic influents were initially fed to the GSBRs and gradually replaced by real PWs, while a sufficiently high volumetric organic loading rate (vOLR, 3 kgCOD/m3d) was granted by dosing proper amounts of readily degradable organic carbon (sodium acetate, NaAc). Compact and well-settling granules developed into both reactors, which were able to treat 100% MS18 (GSBR-A) and 100% IGCC (GSBR-B) wastewater, showing good process performance in terms of organic matter (TOC) and NH4-N removal efficiencies (GSBR-A, 85% and 75%, respectively; GSBR-B, 94% and 78%, respectively). Mature granules in both GSBRs showed high density (GSBR-A, 58 gTSS/Lgran; GSBR-B, 65 gTSS/Lgran) leading to good solid-liquid separation (GSBR-A, SVI8, 39 mL/gTSS; GSBR-B, SVI8, 10 mL/gTSS) and high biomass retention (GSBR-A, 7,5 gVSS/L; GSBR-B, 4,7 gVSS/L). Although a slight inhibition occurred as the PW fraction in the synthetic influents was progressively increased, granular biomass always showed a quick recovery. As the synthetic influents were completely replaced by PWs, the supply of NaAc was progressively reduced and finally suspended in order to minimize the operating costs (the corresponding vOLR was reduced to 0,71 kgCOD/m3d and 1,15 kgCOD/m3d in GSBR-A and GSBR-B, respectively). However, both GSBRs maintained satisfactory process performance and their ability to withstand toxic substances contained in PWs. The results achieved in this study indicate that the aerobic granular sludge technology may be considered as a valid option for the treatment of petrochemical wastewaters, alone (GSBR-A) or in combination (GSBR-B) with conventional systems.

The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

Aerobic sludge granulation is a new technology that has been developed for biological wastewater treatment. Compared with conventional activated sludge, aerobic granules allow better sludge-water separation and a higher biomass concentration. However, the mechanism of the transformation from sludge flocs to granular sludge under the aerobic condition is still unclear. Deterioration of aerobic granules in long-term operation is also a concern for its scale-up application. The present study was conducted to investigate the crucial factors for aerobic granulation and its underlying mechanism. In addition, the stability of aerobic granules under unfavorable conditions and the recovery of deteriorated granules in bioreactors were also studied. For formation of aerobic granules, gelation-facilitated biofilm growth was proposed as a new mechanism for the granulation process. Simulation of granule formation was performed in a well-controlled chemical system to provide an experimental proof for the proposed aerobic granulation theory. Granule formation was achieved in a particle suspension with latex microspheres for bacterial cells and alginate and peptone for extracellular polymeric substances (EPS), together with the cation addition and floc discharge. In the mixture with the dosing of alginate and a small amount of peptone, artificial gels and granules could be well formed, and the artificial granules share the similar micro-structure as the aerobic bacterial granules. However, as the dose of peptone increased, gels were not formed and only large particle flocs were produced. The formation of artificial granules proves that effective EPS interactions with cations and the subsequent gelation are crucial to aerobic granulation in bioreactors. In relation to granulation, the effect of the substrate feeding pattern on the microbial yield was tested. The results show that the bioreactor with a more frequent substrate feeding interval had a lower sludge yield than the reactor (0.45 vs. 0.55) with a less frequent feeding. The sludge fed less frequently was able to store more substrates as intracellular substances, resulting in more biomass growth. Moreover, a long feeding interval would force the biomass into the feast-famine regime, which was found to enhance microbial growth and granulation, producing granules with a compact and stable structure. For the stability of aerobic granules, various factors that would been countered in biological wastewater treatment were experimented. The results show that granules deteriorated in structure under unfavorable conditions, such as a low solution pH (pH~6.0), a high loading rate, and feed of starch instead of glucose into the bioreactors. In some deterioration cases, filamentous bacterial growth became more dominant and the granules became loose and fluffy flocs. Compared to mature granules, fresh granules were less stable and more vulnerable to the unfavorable conditions. As the granules deteriorated in structure, their surface roughness values increased considerably from 35 or less to more than 230. Under a favorable condition with a feed of sodium acetate, the deteriorated granules could be recovered in some reactors. However, deterioration of the granules caused by filamentous growth at a low pH or high loading rate could hardly be recovered.
published_or_final_version
Civil Engineering
Master
Master of Philosophy

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O tratamento de águas residuárias com lodo aeróbio granular apresenta muitas vantagens em comparação ao processo convencional de lodos ativados com lodo floculento. Os grânulos são agregados microbianos densos e compactos que possibilitam uma maior retenção de biomassa no reator biológico e uma elevada capacidade de sedimentação, favorecendo a remoção biológica de matéria orgânica, nutrientes, compostos tóxicos e clarificação final do efluente devido à estrutura e propriedade de sedimentação do lodo. Estes benefícios resultaram em um aumento do interesse de implantação do processo de tratamento com lodo aeróbio granular e a busca de maiores informações à respeito da formação, estabilidade e a influência dos parâmetros operacionais sobre a granulação. Assim, este trabalho apresenta uma revisão bibliográfica com a compilação das informações recentes sobre o lodo aeróbio granular incluindo a possibilidade de utilização dos grânulos aeróbios em biorreatores a membrana, em elevadas temperaturas e as aplicações em plantas de tratamento de larga escala. Foi realizada, ainda, a avaliação da adição de 100 mg.L-1 e 200mg.L-1 de cálcio na estabilidade, resistência mecânica e diâmetro dos grânulos formados em reatores em batelada sequencial alimentados com efluente de uma fábrica de polpa celulósica kraft. Os reatores apresentaram eficiências similares de remoção de matéria orgânica e o diâmetro médio dos grânulos foi de cerca de 11 mm em todos os reatores, embora os grânulos formados no reator que recebeu 100 mg.L-1 de Ca2+ apresentou velocidade de sedimentação 36% superior aos demais e maior resistência mecânica. A melhoria da granulação pode ser obtida ainda pela seleção de microrganismos que contribuem para a formação dos agregados. A produção de substâncias poliméricas extracelulares (SPE) pelas bactérias é um dos fatores que influencia a agregação celular, uma vez que as SPE agem como agente cimentante e atuam na adesão entre as células. A produção de SPE de dezenove isolados microbianos, obtidos de grânulos aeróbios formados no tratamento de efluente de fábrica de papel reciclado foi avaliada e seis isolados dos gêneros Staphylococcus, Agrobacterium, Enterobacter e Rhodococcus melhoraram a granulação biológica. A ausência destes isolados nos testes de co-agregação reduziu a relação entre proteínas e polissacarídeos (relação PN/PS) e diminuiu a formação de agregados.
Aerobic granular sludge wastewater treatment has many advantages over the conventional activated sludge process. The granules are dense and compact microbial aggregates that allow a higher biomass retention in the biological reactor and a high settling velocity, favoring the biological removal of organic matter, nutrients, toxic substances and improves wastewater clarification. Due to the sludge structure and settleability, these benefits have attracted considerable interest in the implementation of the aerobic granular sludge process and givenrise to the need for better understanding of the formation, stability and influence of the operational parameters on the granulation. Thus, this work was divided into three chapters. Chapter 1 presents a review of recent developments on aerobic granular sludge including the possibility of using aerobic granules in membrane bioreactors, at high temperatures and for a full-scale implementation. The addition of divalent cations in the reactors can enhance granulation and granule stability. In Chapter 2, the effect of the addition of 100 mg.L-1 and 200 mg.L- of calcium in the stability, mechanical strength and diameter of the granules formed in sequential batch reactors (SBR) fed with pulp mill effluent was evaluated. The reactors showed similar organic matter removal efficiencies and granule size was approximately 11 mm in all SBR, although the granules formed in the reactor with addition of 100 mg.L- of Ca2+ had a settling velocity 36% higher and greater mechanical resistance than the others. Granulation can also be enhanced by the selection of microorganisms that contribute to the aggregates formation. Bacterial extracellular polymeric substances (EPS) production is one factor that contributes to cell aggregation, since EPS acts as an intercellular cement that may reinforce cohesion inside the bacterial clusters. In Chapter 3, EPS production of nineteen microbial isolates obtained from aerobic granules formed in the recycled paper wastewater treatment was evaluated and six isolates of the genera Staphylococcus, Agrobacterium, Enterobacter and Rhodococcus contributed to biological granulation. The absence of these isolates in the co-aggregation tests reduced the protein-polysaccharide ratio (PN / PS ratio) and reduced the aggregates formation.

In this study the stability and nutrient removal performance of aerobic granules under variable operating pH and variable growth medium was investigated. The results indicated that alkaline pH (pH=9) inhibited nitrogen and phosphorus removal. Moreover, high pH induced granules breakage and resulted in an increased biomass concentration in the effluent. On the other hand, acidic pH (pH=6) did not have significant impacts on stability and nutrient removal efficiency of granules. Changing the growth medium from acetate-based wastewater to municipal wastewater resulted in loss of biological phosphorus removal while ammonium and COD removal stayed the same. The granules disintegrated during the first two weeks after changing the feed; re-granulation of the biomass was observed after the acclimation of bacteria to the new growth medium. However, the granules breakage did not exert significant impact on settling property of biomass.

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.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2017.
For more than a decade, poultry product consumption increased in developed and developing countries, with more than 470 new slaughterhouses being constructed in South Africa (SA). Customer demand for poultry products resulted in a rapidly growing poultry industry, with consequential increases in the quantity of organic solid and liquid waste being produced from the poultry slaughterhouses. Annually, the productivity and profitability within the livestock production sector has increased, an evaluation based on the number of slaughtered and sold animals. Potable water is required for these animals, resulting in the generation of high strength wastewaters. Instantaneous disposal of such wastewaters into the environment is concerning as it results in odour and the spreading of diseases in local rivers and freshwater sources. The generated poultry slaughterhouse wastewater (PSW) contains a high quantity of biodegradable organic, suspended and colloidal matter in the form of proteins, fats, oil and grease (FOG), protein from meat, blood, skin, and feathers, resulting in high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), which can contribute to environmental deterioration if not treated adequately before discharge. On average, PSW contains a high concentration of BOD, COD, nitrogen, pathogenic and non-pathogenic viruses, bacteria and parasites, including their eggs. These characteristics make PSW highly polluted with a large quantity of bird carcass debris including FOG. Due to the high concentration of organic matter and suspended solids in the wastewater, it is necessary to pre-treat the PSW prior to sequential anaerobic treatment. Most of the contaminants present in the PSW can be reduced by means of numerous treatment steps, i.e. physical, chemical and biological treatment. For this study, biological treatment methods, physical separation methods, and a membrane bioreactor system, were used to treat PSW. The biological treatment methods used were an anaerobic digester (AD) followed by a single stage nitrification/denitrification reactor and then a third stage in which an ultrafiltration (UF) and Microfiltration (MF) membrane bioreactor (MBR) was used. The AD used was an Expanded Granular sludge Bed Reactor (EGSB) as anaerobic digestion is one of the most effective biological wastewater treatment methods used, as it reduces the organic matter to even produce biogas as a renewable energy source. The basis of anaerobic treatment method relies on suitable bacteria cultivated in the absence of dissolved oxygen, facilitating decomposition of organic matter into a renewable source such as biogas. Similarly, biological nitrification/denitrification processes for the removal of total nitrogen (TN) in wastewater has become one of the most commonly used processes within the wastewater treatment sector. Nitrification and denitrification processes can be performed by some microorganisms within the wastewater in Wastewater Treatment Plants (WWTPs) The PSW used was collected at different times from a local poultry slaughterhouse in the Western Cape (South Africa) and stored in a refrigerator at 4°C until it was fed to the first stage of the treatment which was the EGSB. Before being fed to the EGSB, the PSW was filtered with a sieve to remove feathers and agglomerated FOG to avoid clogging of the tubing. The EGSB was inoculated with 0.747 L anaerobic granular sludge, had a working volume of 2.7 L, an inner diameter of 0.065 m and a height of 0.872 m respectively. Ceramic marbles with an average diameter of 0.0157m were placed at the bottom of the bioreactor as packing for the underdrain and to maintain the granular sludge within the heated section of the bioreactor. The EGSB was fed with three types of PSW: 50% (v/v), 70% (v/v), which was diluted with distilled water. Thereafter once the system stabilised the reactor was fed with undiluted PSW (100%). Each dilution was operated at different Hydraulic Retention Times (HRTs) and Organic Loading Rates (OLRs), with average HRTs used being 62.5, 57.5 and 49.65 h. Furthermore, the average OLRs were 1, 2 and 3 g tCOD/L.day respectively. The performance of the EGSB was determined using tCOD, Total Suspended Solids (TSS) and FOG, with overall averaged removal rates for these constituents being 69%, 98% and 92% respectively. The highest tCOD removal of 93 % (optimal efficiency) was obtained at an average HRT of 57.5 h with a corresponding average OLR of 2 g tCOD/L.day.

Pour faire face à des réglementations de plus en plus contraignantes, des procédés compacts et performants doivent être développés pour assurer un traitement des effluents efficace et pérenne. La technologie des boues granulaires aérobies permet de coupler productivité et compacité pour autant qu’elle soit maîtrisée. La formation des granules implique des conditions opératoires définies principalement dans des réacteurs discontinus. Afin d’améliorer la capacité de traitement, ce travail a pour objectif de proposer des conditions opératoires permettant l’utilisation des boues granulaires aérobies dans un réacteur en régime continu. Pour cela, la technique de granulation de l’écosystème est contrôlée par l’optimisation du fonctionnement d’un réacteur de laboratoire fonctionnant en discontinu (mode transitoire) puis la procédure obtenue est transposée à une taille de réacteur plus importante. Cette étude montre que la charge massique, le cisaillement et la pression de sélection des boues conditionnent la formation des granules et leurs propriétés. Le fonctionnement du réacteur en régime continu a ensuite été étudié. Il est montré que la structure granulaire a pu être maintenue tout en augmentant l’efficacité du procédé, tout paramètre équivalent par ailleurs (capacité de traitement doublée pour le réacteur continu). In fine, le système a été testé avec un effluent industriel. Un logiciel industriel a été utilisé afin de représenter pour l’optimiser le fonctionnement d’un réacteur fluidisé granulaire tel qu’obtenu expérimentalement. Si le module proposé dans ce logiciel a montré ses limites pour simuler un régime SBR, le modèle MBBR , bien que ne considérant pas la granule dans son ensemble, semble être adéquat pour représenter le fonctionnement en continu. L’utilisation des boues granulaires dans un réacteur continu est une technologie prometteuse mais nécessite des investigations sur son fonctionnement à long terme et sa modélisation
Due to more stringent regulations, wastewater processes need to be more compact and effective. The utilization of aerobic granular sludge conjugates compactness and productivity with the control of the operational. Granulation, which need specific conditions, are mostly operated in batch reactors. To improve the capacity of treatment, this study investigates process conditions for an optimal operation for a continuous reactor working with aerobic granular sludge. First of all, granulation technique is optimized in a laboratory batch reactor (SBR) and results reveal that food to microorganism ratio, shear and selection pressure applied influence pellets’ formation and their properties. Then, this optimized method is successfully scaled-up. After that, the utilization of granules in continuous is studied and this mode increases the reactor capacity while the granular structure is maintained. The utilization of an industrial influent shows reserved results. A commercial software was used to simulate experimental results obtained for a fluidized reactor using pellets. The model, proposed by the software, shows inconsistencies in batch mode. The MBBR model seems more appropriate to simulate continuous mode although the whole pellet is not considered. So, the utilization of aerobic granular sludge in a continuous reactor is a promising technology but further research is needed in the long term operation and its modeling

Depuis une dizaine d'années, les procédés de granulation aérobie sont apparus comme une technologie prometteuse pour le traitement des effluents fortement chargés en azote, phosphore et carbone, tels que ceux issus de l'agro-industrie. La complexité microbienne de ces granules et les mécanismes qui leur donnent des propriétés exceptionnelles de décantation et de cohésion, constituent encore des axes de recherche importants. Dans cette thèse, le travail s'est axé sur un mécanisme encore non étudié : les processus de précipitation des phosphates au cœur des granules microbiennes. Différentes techniques d'analyses spectrales, parfois adaptés pour la première fois à ce type de systèmes, comme la spectroscopie Raman, ont permis de caractériser la nature de ces minéraux formés au cœur des granules. L'analyse menée sur des réacteurs de laboratoires a démontré la présence des phosphates de calcium sous forme d'hydroxyapatite [Ca5(PO4)3(OH)]. Cette précipitation est potentiellement induite par les variations locales de pH et de sursaturation provoqués par les réactions microbiennes à l'intérieur des granules. L'étude des phénomènes de biominéralisation à été étendu aux granules anaérobies issus des réacteurs de type UASB de l'industrie laitière. Un modèle physico-chimique sur les processus de précipitation sous forme matriciel sur AQUASIM®, couplé avec des bases de calcul de sursaturation (PHREEQC®), ont permis d'avancer des hypothèses sur les mécanismes influençant ces processus de biominéralisation, tels que la formation d'un précurseur amorphe de l'hydroxyapatite (ACP), ainsi que d'identifier les constantes de précipitation thermodynamiques (pKsp|20ºC=28.07±0.58) et cinétiques dans différentes conditions opératoires. Grâce au suivi d'un système biologique GSBR (Granular Sludge Sequenced Batch Reactor) pendant plus de 900 jours, la contribution de ce phénomène aux processus de déphosphatation a été estimé (46% dans les conditions testées). L'utilisation de ce processus pour immobiliser efficacement le phosphore et apporter des propriétés physiques stables aux granules a été également discutée. Une évaluation des performances et de la stabilité du réacteur à été mis en œuvre en alternant des cycles anoxies/aérobies ou anaérobies/aérobies vis-à-vis d'une future application industrielle. L'induction locale de la précipitation par les variations de pH et par le relargage des phosphates par les réactions microbiennes, nécessite une modélisation appropriée, qui a été également initiée dans cette thèse
Over the last decade, aerobic granulation processes have araised as a promising technology for treating wastewater effluents containing high nitrogen, phosphorus and carbon concentrations. The microbial complexity of granules and the mechanisms by which they acquire excellent settleability properties, still constitute important research goals to investigate. This thesis is focused on a mechanism that has been little addressed in literature, that is, phosphate precipitation in the core of aerobic granules. Different analytical techniques, sometimes adapted for the first time to this type of systems, like Raman spectroscopy, have let an exhaustive characterization of biominerals in the core of granules. Analyses performed on aerobic granules grown with synthetic fed in a lab-scale SBR (Sequential Batch Reactor), revealed a calcium phosphate core made of hydroxyapatite [Ca5(PO4)3(OH)]. This precipitation phenomenon is induced by local pH and supersaturation gradients issued of biological reactions inside granules. The study of the biomineralization phenomenon has been extended into anaerobic granules coming from UASB reactors at different cheese wastewater treatment plants. A physico-chemical model has been described in a form of matrix with AQUASIM® software, and coupled with a thermodynamic database (PHREEQC®), in an attempt to hypothesize the mechanisms that influence the biomineralization phenomena. It has been proposed the formation of an amorphous precursor (ACP) prior hydroxyapatite precipitation in the core of granules, suggesting the thermodynamic constant (pKsp|20ºC=28.07±0.58) and kinetic constants at different operating conditions. It has been also estimated the contribution of the biomineralization to the overall phosphorus removal process (up to 46% at the operating conditions tested), thanks to the development and study of a GSBR (Granular Sludge Batch Reactor) in labscale, for more than 900 days. The fate of the biomineralization process in granules, regarding the contribution to their stabilization and physical properties, has been also dealt in this thesis. The reactor stability and performances have been assessed by alternating anoxic/aerobic and anaerobic/aerobic cycles, in sights of a future industrial application. The induction of precipitation by local variation of pH and supersaturation issued of biological reactions has been here introduced, although it will need further investigation

Biological nutrient removal has been studied and applied for decades in order to remove nitrogen and phosphorus from wastewater. However, more anthropogenic uses and the continued demand for water have forced the facilities to operate at their maximum capacity. Therefore, the goal of this thesis is to obtain more compact systems for nutrient removal from domestic wastewater. In this sense, optimization and long-term stabilization of high volume exchange ratios reactors, treating higher volumes of wastewater, have been investigated. With the same target, aerobic granular sludge was proposed as a reliable alternative to reduce space and increase loading rates in treatment plants. However, the low organic loading rate from low-strength influents (less than 1 Kg COD•m-3d-1) results in slower granular formation and a longer time to reach a steady state. Because of that, different methodologies and operational conditions were investigated in order to enhance granulation and nutrient removal from domestic wastewater.
L’estudi de l’eliminació biològica de nutrients s’ha dut a terme durant dècades. Tot i això, la influencia de l’home i l’augment de la demanda d’aigua han forçat a les instal•lacions a treballar a la seva capacitat màxima. Així, l’objectiu de la tesi és obtenir sistemes més compactes per a l’eliminació de nutrients de les aigües residuals. En aquest sentit, s’ha investigat l’optimització i estabilització de reactors amb alts volums d’intercanvi, tractant més aigua. Amb el mateix objectiu, el fang granular aeròbic va ser proposat com una alternativa fiable per tal de reduir l’espai i incrementar les càrregues de les depuradores. Tot i això, la granulació amb influents de baixa càrrega (menors a 1 Kg dQO•m-3d-1) resulta més lenta i més dificultosa alhora d’obtenir l’estat estacionari. Per aquesta raó es van investigar diferents metodologies i condicions d’operació per tal de millorar la granularció i l’eliminació de nutrients de les aigües urbanes.

Obiettivo principale di questa tesi di dottorato è stata la valutazione dell'applicabilità della tecnologia a biomasse granulari per il trattamento di reflui suinicoli, come valida alternativa rispetto ai convenzionali sistemi a fanghi attivi. La ricerca si è concentrata sulla valutazione delle condizioni operative maggiormente vantaggiose per la coltivazione dei granuli aerobici e sulla valutazione dell'effetto inibitorio di antibiotici veterinari comunemente presenti all'interno di reflui suinicoli su due specifici consorzi granulari: i batteri ANAMMOX e i granuli aerobici. The main objective of this thesis was the evaluation of the suitability of granular sludge technology as an economically feasible alternative to conventional activated sludge for the treatment of swine wastewaters. The research mainly focused on the evaluation of the most advantageous operating conditions to improve aerobic granules formation and long-term stability, and on the assessment of the inhibitory effect of veterinary antibiotics commonly present in these kind of wastes on two specific granular consortia: the anammox biomass and the aerobic granules.

博士
臺灣大學
化學工程學研究所
98
Aerobic granules are compact, strong microbial aggregates that have excellent settling ability and capability to efficiently treat high-strength and toxic wastewaters. The aerobic granules cultivated with low ammonium and phosphates lost structural stability within 3 days in continuous-flow reactors. Conversely, stable aerobic granules were cultivated in substrate with high levels of ammonium salts that could stably exist for 210 days in continuous-flow membrane bioreactors. The scanning electron microscopy, energy dispersive spectroscopy microanalysis and the confocal laser scanning microscopy imaging detected large amounts of calcium and iron precipitates in granule interiors. The Visual MINTEQ version 2.61 calculation showed that the phosphates and hydroxides were the main species in the precipitate. Internal biofilm was observed in the long-term operating AGMBR system. This study isolated strains in aerobic granule, the surface fouling layer, and biofilm inside hollow-fiber membranes of an aerobic granule membrane bioreactor; analyzed their distributions, sizes, surface charges, and growth behaviors; and determined the quantities of extracellular polymeric substances (EPS) secreted by these strains under different organic loadings. Three strains, which may penetrate the microfiltration membranes, were close relatives of the Ralstonia mannitolilytica strain SDV, Arthrobacter sp. BJQ-2, and Actinobacterium DS3. Among these three strains, only Arthrobacter sp. developed an internal biofilm. The relatively short length of Arthrobacter sp. minimizes resistance to cells moving through the membrane matrix, thereby enhancing its ability to build a biofilm in the interior surface of membranes.

碩士
臺灣大學
化學工程學研究所
98
There are three objectives in this study: to obtain stable aerobic granules in high organic loading rate (OLR) wastewater; to enhance its mechanical strength of aerobic granules and to find proper conservation approaches of the aerobic granules. To obtain the stable aerobic granules, nitrogen source, ammonium (NH4-N) and nitrate (NO3-N), are prepared in three ratios (i.e. 100/0, 40/60, 20/80) while carbon source (propionic acid and ethanol) are fixed as feed. Following the three nitrogen ratios, aerobic granules are generated after two weeks in three sequence batch reactor (SBR), namely R1, R2 and R3. OLR in the three SBRs are gradually increased from 2.5 to 14 kg COD.m-3.day-1 in 25-days continuous operation. Broken of R3 granules are firstly observed at OLR= 6.87 kg COD.m-3.day-1, while R2 granules are then broken at OLR= 14.24 kg COD.m-3.day-1. R1 granules are not found any broken and still survive at the highest OLR (21.85 kg COD.m-3.day-1) till the end of the experiment. The result shows that nitrate (NH4-N) as the sole nitrogen source (R1) is the most stable among the three SBR experiments. Consequently, R1 granules are transfered to continuous stirred tank tractor (CSTR) and continuously running till a new-record (220 days) at the highest OLR forever (39 kg COD.m-3.day-1). To increase mechanical strength of aerobic granules, two coating techniques, namely inside and outside coating, are developed. Inside coating are found easier fabricated and more stable than outside-coating granules. Among seven tested oversaturation solutions, Mg3(PO4)2 and CaSO4 achieved the highest mechanical strength. For granules coating by MgCO3, the strcture of granules are observed rigid in alkalne condition (pH=12) and its bioactivity in acid condition (pH=3) is better than the uncoated granules. Residual numbers of the MgCO3-coated granules in CSTR are found existing more than the uncoated ones during long-term CSTR operation (220 days). Diversity of microbial community in the aerobic granules is getting three uniform bacterial species (i.e. Rhizobium sp., Brevundimonas sp., Nitratireductor sp.) at 160-days continuous running. Drying granules are carried out in order to reserve the aerobic granules. It is found the recovered granules still remian its bioactivity (i.e. COD degradation). Three drying approaches, i.e. drying by acetone, in dark and after coating, are found better than the other five drying approaches in terms of bioactivity recovery. Bioactivity of the recovered aerobic granules storaging after 22 days and 78 days are both the same as undried ones. Molecular biological techniques, i.e. DGGE, are applied to charaterize bacterial species of aerobic granules. Three species, Flavobacterium sp., Trigonala sp., and Arthrobacter sp., are found in the dried and recovered aerobic granules.

碩士
國立臺灣大學
化學工程學研究所
94
The dissolved oxygen (DO) concentration in aerobic granules were measured using microelectrodes, based on which the diffusivity of oxygen was thereby estimated. Considering granules of low bioactivity, the acetate-fed granules of size 1.28-2.50 mm exhibited diffusivity of 1.24-2.28 x10-9 m2 s-1; while phenol-fed granules of size 0.42-0.78 mm had diffusivities of 2.50-7.65 x10-10 m2 s-1. Based on confocal laser scanning microscope testing the interior of granules exhibited layered structure. The steady-state DO concentrations of phenol-fed granule were recorded, showing that oxygen had been depleted in the surface reacting layer of granule. The oxygen diffusivity inside this reacting layer was estimated 1.34-1.82x10-9 m2 s-1 by assuming an mean oxygen concentration. Considering both steady-state and transient DO responses, the acetate-fed granule had diffusivity of oxygen of 0.6-1.3x10-9 m2s-1, while the phenol-fed granules had diffusivity of 2.5-4.6x10-10m2s-1. Both reaction and diffusion limits the oxygen transport in aerobic granules.

Thesis (Ph. D.)--University of Notre Dame, 2005.
Thesis directed by Robert L. Irvine for the Department of Civil Engineering and Geological Sciences. "February 2005." Includes bibliographical references (leaves 160-169).

碩士
淡江大學
水資源及環境工程學系碩士班
101
Hemodialysis wastewater contains high concentration of ammonia nitrogen (about 60~70 mg/L). It may cause serious water pollution if the wastewater is not properly treated. Literatures showed that aerobic granule process has good stability, maintains high sludge concentration, withstands high organic loadings, and can remove ammonia nitrogen effectively. In this study, aerobic granular process was used to treat hemodialysis wastewater collected from a local clinic. Both aerobic granular process and activated sludge process in the existing activated sludge process were compared side-by-side for removing chemical oxygen demand (COD) and ammonia nitrogen of hemodialysis wastewater. At first, cultivation of aerobic granule using hemodialysis wastewater was conducted in the laboratory to observe granule formation and treated water quality. The result shows that aerobic granule can be cultivated in SBR reactor using hemodialysis wastewater as substrate, having outstanding treatment efficiency. After a three-week operation, aerobic granules were formed in SBR reactor, achieving more than 95% of COD and ammonia nitrogen removal efficiency. Besides, complete oxidation of ammonia nitrogen to nitrate nitrogen was observed in the aerobic granule process. Thereafter, SBR reactor was moved onsite to the clinic and was operated side-by-side with the activated sludge process in the existing wastewater treatment plant. Influent and effluent of SBR reactor and of the existing treatment process were collected and brought back to laboratory regularly for water quality analysis to compare the performance of two systems. No aerobic granules formed during the course of six-month study due to raw water containing sodium hypochlorite, which was used to sterilize medical devices at the end of each business day. Therefore, the onsite SBR reactor was operated as a normal activated sludge system. Less than 85% of COD and ammonia nitrogen removal efficiency was achieved for both systems. Furthermore, the SBR reactor was only capable of oxidizing ammonia nitrogen into nitrite nitrogen, while no ammonia nitrogen removal was observed for the activated sludge process of the existing treatment plant. Comparison of SBR reactor in the laboratory with SBR reactor onsite, this study confirmed that aerobic granule process achieved better nitrification efficiency and produced better treated water quality than activated sludge process.

碩士
國立臺灣大學
化學工程學研究所
104
Phosphorus recovery has been a global issue due to the depletion of phosphorus resource and the contamination of its release to the aquatic environment. Precipitation formation is a promising approach to recover phosphorus by extracting phosphate and ammonium ions in wastewaters; however, the operating costs need to be considered when the nitrogen and phosphorus loading increase. In this study, a modified process is suggested, using an aerobic granule forward osmosis membrane bioreactor (AG-FOMBR) to estimate the recovery efficiency. In this bioreactor, organic matters were digested by the biological process while phosphate ions were rejected by the Thin-film Composite (TFC) FO membrane and accumulated. Aerobic granules, as a compact form of microbial aggregates with good settleability and capability to treat high-strength wastewaters, were seeded to compare the membrane water fluxes with the sludge form. The AG-FOMBR showed 95.8%, 37.4%, and 100% overall removal of PO43--P, NH4+-N, and TOC in the first stage, and 95.5%, 46.0%, and 100% in the second stage, respectively. The solutes leakage of TFC membrane is measured and discussed. Recovery benefits through AG-FOMBR, OMBR, and FO (directly removing phosphorus from synthetic wastewater by FO) are evaluated. The global phosphorus recovery efficiency in this suggested reactor was 97.0% in average during the 75-day operation.

Aerobic granular sludge (AGS) technology is a next-generation technology for the biological treatment of wastewater. The advantages of AGS in terms of small footprint, low operation and capital cost and high effluent quality makes it a strong candidate for replacing conventional biological wastewater treatment based on activated sludge (CAS) process, and potentially become the standard for biological wastewater treatment in the future. Saline wastewater is generated from many industrial processes as well as from the use of sea water as a secondary quality water for non-potable use such as toilet flushing to mitigate shortage of fresh water in some coastal cities. Salt is known to inhibit biological wastewater treatment processes in terms of organic and nutrient removal. In the first part of my dissertation, I conducted three lab-scale experiments to 1) evaluate the effect of salt on granulation and nutrient removal in AGS (330 days); 2) develop engineering strategies to mitigate the adverse effect of salt on nutrient removal of AGS (164 days); and 3) compare the effect of salt on the stoichiometry and kinetics of different phosphate accumulating organisms (PAO) clades (PAOI and PAOII) and to determine the effect of potassium and sodium ions on the activities of different PAO clades (225 days). Like other artificial microbial ecosystems (e.g. CAS plant and anaerobic digester), a firm understanding of the microbial ecology of AGS system is essential for process design and optimization. The second part of my dissertation reported the first microbial ecology study of a full-scale AGS plant with the aim of addressing the role of regional (i.e. immigration) versus local factors in shaping the microbial community assembly of different-sized microbial aggregates in AGS. The microbial communities in a full-scale AGS plant in Garmerwolde, The Netherlands, was characterized periodically over 180 days using Illumina sequencing of 16S ribosomal RNA amplicons of the V3-V4 regions. Overall, the discovery of this PhD study sheds light on the application of AGS for the treatment of saline wastewater and deepens our understanding on the microbial ecology of AGS systems, which is essential for process design and optimization.

Thesis (M.S.)--University of Wisconsin--Madison, 2000.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 85-87).

Over the last decade, aerobic granulation processes have araised as a promising technology for treating wastewater effluents containing high nitrogen, phosphorus and carbon concentrations. The microbial complexity of granules and the mechanisms by which they acquire excellent settleability properties, still constitute important research goals to investigate. This thesis is focused on a mechanism that has been little addressed in literature, that is, phosphate precipitation in the core of aerobic granules. Different analytical techniques, sometimes adapted for the first time to this type of systems, like Raman spectroscopy, have let an exhaustive characterization of biominerals in the core of granules. Analyses performed on aerobic granules grown with synthetic fed in a lab-scale SBR (Sequential Batch Reactor), revealed a calcium phosphate core made of hydroxyapatite [Ca5(PO4)3(OH)]. This precipitation phenomenon is induced by local pH and supersaturation gradients issued of biological reactions inside granules. The study of the biomineralization phenomenon has been extended into anaerobic granules coming from UASB reactors at different cheese wastewater treatment plants. A physico-chemical model has been described in a form of matrix with AQUASIM® software, and coupled with a thermodynamic database (PHREEQC®), in an attempt to hypothesize the mechanisms that influence the biomineralization phenomena. It has been proposed the formation of an amorphous precursor (ACP) prior hydroxyapatite precipitation in the core of granules, suggesting the thermodynamic constant (pKsp|20ºC=28.07±0.58) and kinetic constants at different operating conditions. It has been also estimated the contribution of the biomineralization to the overall phosphorus removal process (up to 46% at the operating conditions tested), thanks to the development and study of a GSBR (Granular Sludge Batch Reactor) in labscale, for more than 900 days. The fate of the biomineralization process in granules, regarding the contribution to their stabilization and physical properties, has been also dealt in this thesis. The reactor stability and performances have been assessed by alternating anoxic/aerobic and anaerobic/aerobic cycles, in sights of a future industrial application. The induction of precipitation by local variation of pH and supersaturation issued of biological reactions has been here introduced, although it will need further investigation.

The widespread occurrence of various types of emerging contaminants (ECs) has become an issue of high concern. Among ECs, pharmaceuticals and its metabolites deserve particular attention as their presence, continuous release and persistence in water bodies pose serious health issues affecting the entire ecosystem. It is important to understand the biodegradation of such molecules to devise strategies to avoid dispersal of these ECs in the environment. The work described in this thesis aimed at investigating of the microbial degradation of two pharmaceutical compounds, carbamazepine (CBZ) and diclofenac (DCF). On a first approach, selective enrichments using activated sludge from a municipal wastewater treatment plant (WWTP) were established for each pharmaceutical. One strain able to degrade DCF (strain Brevibacterium sp. D4) and two strains able to degrade CBZ (strains Starkeya sp. C11 and Rhizobium sp. C12) were isolated and their ability to biodegrade the pharmaceutical compounds supplied as a sole carbon source and with periodic feedings with acetate was assessed in batch cultures. Strain Brevibacterium sp. D4 was able to biodegrade ca. 35% of 10 mg L-1 of DCF supplied as a sole carbon source in 30 days. Supplementation with acetate enhanced biodegradation to ca. 90%. Both strains were able to degrade ca. 30% of 10 mg L-1 CBZ in 30 days, with no improvement in the presence of a supplementary carbon source. On a second approach, the biodegradation of each pharmaceutical compound by the bacterial strain Labrys portucalensis F11 was investigated. This strain was selected due to its ability to biodegrade recalcitrant compounds, including pharmaceuticals. CBZ biodegradation by strain F11 was assessed with the pharmaceutical supplied as sole carbon source, with ca 95% biotransformation of 10 mg L-1 CBZ achieved in 30 days. The supplementation with acetate led to complete CBZ biotransformation at a faster rate. Biotransformation of CBZ by strain F11 resulted in of 14 intermediary metabolites detected and identified using Ultra-high Performance Liquid Chromatography-Quadrupole Time-Of-Flight Mass Spectrometry (UPLC-QTOF/MS/MS), which enabled the proposition of a biotransformation pathway. The toxicity of untreated and treated CBZ solutions was investigated using Vibrio Fischeri and Lepidium sativum acute toxicity tests and Toxi-Chromo Test. At concentrations ranging from 0.5 to 10 mg L-1 only Vibrio Fischeri was moderately affected by the presence of CBZ and/or its degradations products. DCF was supplied to strain F11 cultures as a sole carbon source at concentrations ranging from 0.5 to 10.0 mg L-1 and a biotransformation extent of ca 70% of DCF was achieved in 30 days, for the highest concentration. Supplementation with acetate resulted in complete degradation of 0.5 mg L-1 of DCF in 6 days and 10.0 mg L-1 of DCF in 25 days. Stoichiometric liberation of chlorine was observed. The identification of biodegradation intermediates was performed. A possible degradation pathway was proposed based on the chemical structure of 12 metabolites identified by UPLC-QTOF/MS/MS. The stoichiometric liberation of chlorine and the lack of detection of metabolites at the end of the experiments indicated complete degradation of DCF by strain F11. An aerobic granular sludge sequencing batch reactor (AGS-SBR), established using activated sludge from a WWTP and bioaugmented with strain F11, was used for the treatment of an aqueous stream containing DCF. Overall, the bioreactor main biological processes, such as Chemical Oxygen Demand (COD), nitrogen and phosphorous removal were not affected by the addition of DCF in the feeding stream at 10.0 mg L-1. Even though the AGS-SBR was not able to remove DCF, it was robust to maintain its main biological functions throughout the 286 days at different operational conditions. Along bioreactor operation, microbial community dynamics was monitored. Eleven bacterial culturable isolates were retrieved and tested for DCF biodegradation; the highest degradation obtained was of ca. 34% of 10.0 mg L-1 DCF supplied as a sole carbon source. The AGS displayed a diverse bacterial community, with visible changes along operation. Strain F11 was present throughout the entire reactor operation, as demonstrated by sequencing of bands excised from Denaturing Gradient Gel Electrophoresis of extracted DNA. DCF biodegradation capability of the AGS was tested in batch mode with periodic feedings with acetate, resulting in ca. 72% removal of 10.0 mg L-1 DCF removal. The higher degradation extent of AGS compared to the degradation obtained by the retrieved isolates suggested that strain F11 was contributing to the process.
A ocorrência de vários tipos de contaminantes emergentes (CEs) tornou-se um assunto de grande preocupação. Entre os CEs, os fármacos e os seus metabolitos merecem particular atenção, dado que a sua presença, liberação contínua e persistência nos ambientes aquáticos apresenta sérios problemas de saúde afetando todo o ecossistema. É crucial entender a biodegradação deste tipo de moléculas para planear estratégias para evitar a a sua dispersão no ambiente. O trabalho descrito nesta tese teve como objetivo a investigação da degradação microbiana de dois fármacos, carbamazepina (CBZ) e diclofenac (DCF). Numa primeira abordagem, foram estabelecidos enriquecimentos seletivos para cada fármaco usando lamas ativadas de uma estação de tratamento de águas residuais (ETAR). Uma estirpe capaz de degradar DCF (Brevibacterium sp. D4) e duas estirpes capazes de degradar CBZ (Starkeya sp. C11 e Rhizobium sp. C12) foram isoladas e a sua capacidade de biodegradar os compostos farmacêuticos suplementados como única fonte de carbono e com alimentação periódica com acetato foi avaliada em culturas líquidas. A estirpe Brevibacterium sp. D4 foi capaz de biodegradar ca. 35% de 10 mg L-1 of DCF, alimentada como fonte única de carbono em 30 dias. A suplementação com acetato aumentou a biodegradação ca. 90%. Ambas as estirpes foram capazes de degradar 30% de 10% L-1 de CBZ em 30 dias, sem melhoria na biodegradação com uma fonte suplementar de carbono. Numa segunda abordagem, a biodegradação de cada composto farmacêutico pela estirpe bacteriana Labrys portucalensis F11 foi investigada. Esta estirpe foi selecionada devido à sua capacidade de biodegradar compostos recalcitrantes, incluindo fármacos. A biodegradação da CBZ 10 mg L-1 de CBZ pela estirpe F11 foi de ca 95% em 30 dias. A suplementação com acetato resultou na completa biotransformação com uma taxa mais rápida. A biodegradação da CBZ pela estirpe F11 leva à produção de intermediários, tendo sido detetados e identificados 14 metabolitos intermediários usando Ultra-high Performance Liquid Chromatography-Quadrupole Time-Of-Flight Mass Spectrometry (UPLC-QTOF/MS/MS), permitindo propor uma via de biotransformação. A toxicidade de soluções de CBZ não tratadas e tratadas foi investigada usando testes de toxicidade aguda Vibrio Fischeri e Lepidium sativum e o Toxi-Chromo Test. A concentrações entre 0.5 e 10 mg L-1 apenas Vibrio Fischeri foi moderadamente afetado pela presença de CBZ e/ou seus produtos de degradação. O DCF foi alimentado às culturas de F11 como uma única fonte de carbono a concentrações entre 0.5 to 10.0 mg L-1 e a biotransformação de ca 70% de DCF foi alcançada em 30 dias, para a concentração mais elevada. A suplementação com acetato resultou na completa degradação de 0.5 mg L-1 de DCF em 6 dias e de 10.0 mg L-1 de DCF em 25 dias. Foi observada liberação estequiométrica de cloreto. A identificação dos intermediários de biodegradação foi realizada. Uma possível via de degradação foi proposta com base na estrutura de 12 metabolitos identificados por (UPLC-QTOF/MS/MS). A libertação estequiométrica de cloreto e a não deteção de metabolitos no final das experiências, indicou a degradação completa do DCF pela estirpe F11. Um reator granular sequencial descontinuo de grânulos aeróbios (AGS-SBR) foi estabelecido a partir de lamas ativadas de uma ETAR e bioaumentado com a estirpe F11, e foi usado para o tratamento de um influente sintético contendo DCF. No geral, os principais processos biológicos, como remoção de carência química de oxigénio (CQO), e de nutrientes, azoto e fósforo, não foram afetados pela adição de DCF no fluxo de entrada a 10 mg L-1. Embora o AGS-SBR não tenha sido capaz de remover o DCF, mostrou-se robusto para manter as principais funções biológicas ao longo de 286 dias com diferentes condições testadas. Ao longo da operação, a dinâmica da comunidade microbiana foi monitorizada. Onze isolados bacterianos cultiváveis foram recuperados e testados para a biodegradação do DCF; a maior taxa de degradação obtida foi ca 34% de 10 mg L-1 DCF como única fonte de carbono. O AGS-SBR apresentou uma comunidade bacteriana diversificada, com alterações visíveis nas diferentes condições testadas. A estirpe F11 manteve-se presente durante toda a operação do reator, como demonstrado por sequenciação das bandas excisadas a partir do Gel de Eletroforese em Gradiente Desnaturante. A biodegradação de DCF pelos grânulos aeróbios foi testada em batch com alimentações periódicas com acetato, resultando em ca. 72% de remoção de 10.0 mg L-1 de DCF. A maior extensão de degradação dos grânulos comparativamente com a degradação obtida pelos isolados sugere que a estirpe F11 contribuiu para o processo.

The treatment of synthetic landfill leachate and raw landfill leachate were investigated using two sets of 3 L aerobic sequencing batch reactors (SBR): activated sludge SBR (ASBR) and granular SBR (GSBR). In synthetic young landfill leachate treatment, GSBR was more efficient in nitrogen and carbon removal than ASBR. During the steady period of the experiment, 99% total ammonium nitrogen (TAN) was removed through nitritation and nitrification in GSBR with an average influent TAN concentration of 498 mg/L. On the contrary, complete nitrification was not achieved in ASBR with a nitrification efficiency of 77±10%. GSBR also presented higher efficiency in denitrification and COD removal compared to ASBR. Phosphorus removal efficiency was almost identical in both reactors. Synthetic old landfill leachate treatment using GSBR maintained the stable COD removal efficiency at 66%, when the ammonia nitrogen to the maximum of 465±46 mg/L. The ASBR required a start-up of at least 30 days and removed 59±9% of COD when an influent ammonia nitrogen concentration about 200 mg/L. The GSBR was also more efficient than the ASBR for nitrogen removal. The granular sludge reached a maximum ammonia removal of 95±7%, whereas 96±5% was achieved by ASBR. The phosphorus removal was likely affected by the free nitrous acid (FNA) and the low biodegradability of tannic acid. In raw landfill leachate treatment, the total ammonia nitrogen (TAN) removal efficiency was in GSBR approximately 99.7%. However, the ASBR treatment did not show a consistent performance in TAN removal. TAN removal efficiency decreased with increasing ammonia concentration in the influent. Nitrification in GSBR was partially inhibited at FA concentrations of 48 to 57 mg/L, which was two times more than the FA concentration that inhibited nitrification in ASBR. In terms of chemical oxygen demand (COD) removal, low removal efficiencies of 17% and 26% were observed in ASBR and GSBR, respectively. The low COD removal efficiencies were associated with the refractory organic content of the leachate used in this study, which resulted in a poor phosphorous removal performance as well. Overall, aerobic granular sludge showed a better performance in removing nutrients and organic matter from young or old landfill leachate, being more efficient than the conventional suspended growth activated sludge. Therefore, the use of AGS for leachate treatment should be encouraged. Further investigations should also be addressed, especially with a focus on improving SND and phosphorus removal efficiencies.
May 2017

Tese de doutoramento em Engenharia Química e Biológica
Nesta tese foi operado um reator descontínuo sequencial, inoculado com AGS (SBR-AGS) proveniente de um sistema granular à escala real, para o tratamento de água residual sintética, primeiramente sem qualquer adição de fármaco e posteriormente adicionando os estrogénios 17β- estradiol (E2) e 17α-etinilestradiol (EE2) e o antibiótico sulfametoxazol (SMX). Foram ainda desenvolvidas e otimizadas novas metodologias de amostragem e separação das frações baseadas no conteúdo em sólidos suspensos, de aquisição em microscopia de campo claro e em lupa binocular, para a fração de flocos e grânulos, respetivamente, assim como os necessários programas de processamento e análise quantitativa de imagens (QIA). Foram ainda aplicadas diferentes técnicas quimiométricas, incluindo a regressão linear múltipla (MLR), análise de componentes principais (PCA), árvores de decisão (DT) e análise discriminante (DA) aos dados relativos à estrutura e morfologia da biomassa, assim como aos parâmetros operacionais do reator. O sistema de SBR-AGS, após um processo de maturação da biomassa aeróbia, apresentou um claro predomínio da fração granular sobre a fração flocular, caracterizado por uma predominância de grânulos de elevado tamanho (superiores a 2.5 mm em diâmetro), robustos, estruturalmente estáveis e com uma boa sedimentabilidade. Adicionalmente verificou-se o predomínio da fração orgânica nos agregados, face à inorgânica, não tendo sido verificados fenómenos de bulking no sistema. A aplicação de PCA aos dados obtidos permitiu isolar claramente os clusters correspondentes aos períodos operacionais com a biomassa madura e com a adição dos diferentes fármacos e identificar as principais correlações entre os parâmetros estudados. No tocante à previsão por MLR dos sólidos suspensos (totais – TSS e voláteis – VSS) de ambas as frações, da densidade da biomassa e do índice volumétrico de lamas, foram obtidos resultados promissores. A aplicação de DA e DT aos dados obtidos permitiu distinguir, com sucesso, os diferentes períodos operacionais e identificar as amostras contendo PhACs.
In this thesis, a laboratory scale sequencing batch reactor (SBR) inoculated with AGS from a fullscale WWTP was operated for the treatment of a synthetic wastewater, first in the absence of PhACs and later in the presence of the 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) steroid estrogens and the sulfamethoxazole (SMX) sulphonamide antibiotic. New methodologies for sampling and biomass granular and floccular fractions separation, based on the suspended solids content, as well as bright field and stereomicroscopy monitoring and image acquisition, were also developed and optimized, as well as the necessary quantitative image analysis (QIA) routines. In order to best comprehend the collected data, different chemometric tools were also applied, including multilinear regression (MLR), principal component analysis (PCA), discriminant analysis (DA) and decision trees (DT) to the morphological and structural parameters of the biomass and the main operational parameters of the SBR. The SBR-AGS system, after a maturation process of the aerobic biomass, showed a clear predominance of the granular fraction over the floccular one, characterized by a predominance of granules of large size (larger than 2.5 mm in diameter), robust, structurally stable and with good settling properties. Additionally, there was a predominance of the organic fraction in the aggregates, compared to the inorganic one, with no bulking phenomena being observed in the system. The performed PCA allowed to clearly isolate the clusters corresponding to the experimental periods with mature AGS and E2, EE2 and SMX addition, and enlighten the studied parameters interrelationships.Regarding the MLR forecast of both fractions total (TSS) and volatile (VSS) suspended solids, biomass density and sludge volumetric index, promising results were obtained. Besides, the application of DA and DT allowed to identify the different operational periods, and successfully classify the samples in the presence and in absence of the PhAC.
The work presented in this thesis was financially supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.

A variety of organic pollutants reach wastewater treatment plants (WWTP), often associated with high salinity levels, making their treatment challenging. Aerobic granular sludge (AGS) technology is thought to protect the microbial communities from stress due to the high content of extracellular polymeric substances (EPS). There is an increasing need to turn WWTP more efficient, with a range of opportunities for resource recovery to integrate them into the circular economy concept. The work described in this thesis aimed to explore AGS biomass as a source of EPS and to understand the variations of EPS production facing different stressors, namely 2-fluorophenol (2-FP) and salinity. Particular attention was given to the microbial communities, diversity and function, of the investigated systems. The recovery of EPS from AGS represents an opportunity for valorization of surplus biomass. AGS from a full-scale WWTP treating urban wastewater was regularly collected for 4 months to assess variability in EPS composition and in granular morphology. Variations in the EPS composition occurred with time, with proteins and humic acids as the main EPS components and polysaccharides and DNA as minor constituents. An extra purification step led to the recovery of a purer EPS form with a rather homogeneous composition however the yield of each EPS component decreased, especially for polysaccharides. Yield and product homogeneity are key features for downstream application of the recovered EPS. The effect of intermittent short-term loadings of 2-FP and low to moderate salinity wastewater on the performance and EPS production of an AGS system was studied. Ammonium removal was highly inhibited by stressors, recovering when 2-FP feeding ceased. Phosphate removal, initially disturbed by exposure to stress conditions, recovered when stressors were still present. EPS composition and concentration in the granules decreased from 133.3 to 33.7 mg/g VSS of AGS during the first phases of stress but its production recovered to 176.1 mg/g VSS of AGS even in the stressor’s presence. The nutrient removal recovery after exposure to stressors and the increased EPS production response support the robustness of AGS systems to deal with intermittent stressful conditions. EPS recovered from AGS were used as an immobilizing agent for Rhodococcus sp. FP1, a 2-FP degrading strain. The produced EPS granules exhibited 2-FP degrading ability of 100%, retaining its original activity up to 2 months storage. Moreover, the EPS granules were used to bioaugment an AGS reactor intermittently fed with low to moderate saline wastewater amended with 2-FP. After bioaugmentation, complete 2-FP removal occurred and phosphate and ammonium removal (previously impaired by 2-FP load) improved from 14 to 46% and from 25 to 42%, respectively. After bioaugmentation, strain FP1 was detected up to 3 days in the reactor effluent by qPCR and eleven bacterial isolates able to degrade 2-FP were retrieved from the AGS. Maintenance of cell viability through storage and improvement of bioreactor.
Uma grande variedade de poluentes orgânicos chega às estações de tratamento de águas residuais (ETARs), muitas vezes associados a altos níveis de salinidade, tornando o seu tratamento um desafio. Na tecnologia de grânulos aeróbios (AGS), as comunidades microbianas tendem a estar protegidas do stress ambiental pela presença de substâncias poliméricas extracelulares (EPS). Há uma necessidade crescente de tornar as ETARs mais eficientes, integrando-as no conceito de economia circular recorrendo à recuperação de recursos. O trabalho descrito nesta tese pretende explorar a biomassa AGS como fonte de EPS e compreender as variações da sua produção face a diferentes fatores de stress, nomeadamente, de 2-fluorofenol (2-FP) e salinidade. Além disso, foram investigadas as comunidades microbianas dos sistemas AGS, tendo em conta a diversidade e função das mesmas. A recuperação do EPS representa uma oportunidade de valorização do excedente de biomassa. O AGS de uma ETAR urbana foi coletado regularmente ao longo de 4 meses para avaliar a variabilidade da composição do EPS e da morfologia granular. Ao longo do tempo ocorreram variações na composição do EPS, sendo as proteínas e ácidos húmicos os principais componentes e polissacarídeos e DNA constituintes secundários do EPS. Uma etapa extra de purificação conduziu à recuperação de uma forma de EPS mais pura com uma composição mais homogénea, contudo, o rendimento de cada componente diminuiu, especialmente dos polissacarídeos. O rendimento e a homogeneidade do produto são essenciais para a futura aplicação do EPS recuperado. Foi estudado o efeito da presença intermitente e de curta duração de 2-FP e de baixa a moderada salinidade no desempenho e na produção de EPS num sistema AGS. A remoção de ião amónio foi inibida pelos fatores de stress, recuperando quando a alimentação com 2- FP cessou. A remoção do ião fosfato, inicialmente perturbada, recuperou quando os fatores de stress ainda estavam presentes na alimentação. A composição e a concentração de EPS nos grânulos diminuiu de 133,3 para 33,7 mg/g VSS de AGS durante as primeiras fases de stress mas, a sua produção recuperou para 176,1 mg/g VSS de AGS, mesmo na presença dos fatores de stress. A recuperação da remoção de nutrientes após a exposição a fatores de stress e o aumento da produção de EPS comprovam a robustez dos sistemas AGS para lidar com condições de stress intermitentes. EPS recuperado de AGS foi usado como um agente imobilizador para Rhodococcus sp. FP1, uma estirpe degradadora de 2-FP. Os grânulos de EPS produzidos foram capazes de degradar 2-FP a 100%, mantendo sua atividade original até 2 meses de armazenamento. Além disso, os grânulos de EPS foram usados para o bioaumento de um reator AGS alimentado de forma intermitente com 2-FP e salinidade baixa a moderada. Após o bioaumento, ocorreu a remoção completa de 2-FP e, a remoção dos iões fosfato e amónio (previamente afetada pela presença de 2-FP) aumentou de 14 para 46% e de 25 para 42%, respetivamente. A estirpe FP1 foi detetada por qPCR até 3 dias após o bioaumento no efluente do reator e, 11 isolados bacterianos degradadores de 2-FP foram recuperados do AGS. A manutenção da viabilidade celular durante o armazenamento e a melhoria do desempenho do reator sem alterar os seus parâmetros operacionais são as principais vantagens desta estratégia alternativa de bioaumento. As variações nos padrões taxonómicos e funcionais dos microbiomas dos dois reatores AGS, sob diferentes regimes de alimentação, foram avaliadas e associadas ao desempenho do reator e à produção de EPS. Estiveram presentes em cada reator comunidades dinâmicas e adaptáveis, com uma sucessão de diferentes espécies, garantindo a resiliência dos principais processos de remoção e produção de EPS. No fim do período de operação, o reator não bioaumentado e exposto a fatores de stress por períodos mais curtos mostrou uma comunidade com maior riqueza, com um claro domínio de membros da classe Flavobacteriia e um microbioma core que representa ca. 13,8% de todas as sequências, enquanto que o reator bioaumentado exposto a fatores de stress por períodos mais longos, mostrou uma distribuição mais uniforme das classes bacterianas. No reator bioaumentado, o género Rhodococcus persistiu nos grânulos ao longo das fases de alimentação com 2-FP. A inferência funcional in silico sugere que diferentes mecanismos de adaptação ao ambiente externo foram ativados em cada reator. A redundância funcional e a diversidade microbiana, juntamente com uma sucessão de espécies, são provavelmente responsáveis pela recuperação dos processos de remoção de nutrientes e produção de EPS, especialmente quando as condições de alimentação mudam em ambos os reatores.

Dissertação de mestrado, Qualidade em Análises, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2017
Pharmaceuticals have become priority emerging environmental pollutants. Environmental monitoring and toxicological studies are essential to establish maximum permissible limits in the environment. Furthermore, innovative wastewater treatment is required for their degradation. Águas do Algarve is constructing an aerobic granule plant to modernize wastewater treatment for the cities of Faro and Olhão. The company is interested in research regarding granule ability to degrade pharmaceuticals detected in wastewater influent. Two aerobic granule sequencing batch reactors were constructed and operated at laboratory scale using different cycles (anaerobic/aerobic and aerobic). The efficiency of the reactors and type of operating conditions was investigated for the degradation and removal of ibuprofen and its metabolites 2-hydroxyibuprofen, 1-hydroxyibuprofen and carboxyibuprofen. Two methods, high performance liquid chromatography (HPLC) and micellar electrokinetic chromatography (MEKC), a form of capillary electrophoresis, coupled with UV/Vis, were developed to detect and quantify ibuprofen and its metabolites. Solid phase extraction was used to preconcentrate the compounds to method detection limits, however recoveries were problematic. Eluents were dried and reconstituted in solvent (milli-q water) for compatibility to both methods. Separation conditions for the compounds were optimized. Both methods were validated in solvent (milli-q water) for linearity, recovery, LOD, LOQ, precision (repeatability and intermediate precision), range and selectivity. Selectivity could be obtained for both methods. However, acceptable linearity, LOD, LOQ, repeatability and recovery could not be established in the desired working range. Additionally, robustness problems particularly for the MEKC method may have affected validation results. For some compounds, both methods failed to meet statistical tests applied for acceptance of linearity and repeatability. Solvent and synthetic wastewater calibration were compared using student’s ttest. There was no statistically significant difference between the curves for the HPLC method in contrast to those of the MEKC method. The methods were applied to synthetic wastewater samples taken from the SBRs. Each method detected different analytes with 1-hydroxyibuprofen observed in HPLC and carboxyibuprofen observed in MEKC. The calculated concentrations exceeded method range. Revalidation of both methods and reanalysis of the samples is required to verify accuracy of results and confirm suitability for intended application.