Aerobic biodegradation kinetics of 4-Chlorophenol (4-CP) and 2,4-Dichlorophenol (2,4-DCP) by acclimated mixed cultures were examined separately and in mixture using batch and sequencing batch reactors (SBRs). Biodegradation abilities of acclimated mixed cultures were also compared with those of isolated pure species. Complete degradation of chlorophenols and high COD removal efficiencies were observed throughout the SBRs operation. During the degradation of 4-CP, 5-chloro-2-hydroxymuconic semialdehyde, (the -meta cleavage product of 4-CP), accumulated but was subsequently removed completely. Chlorophenol degradation rates increased with increasing chlorophenols concentration in the feed of the SBRs. Gradually decreasing feed peptone concentration did not adversely affect chlorophenol degradation profiles in SBRs. Only competent biomass was thought to be responsible for chlorophenol degradation due to required unique metabolic pathways. It was assumed that the fraction of competent biomass (specialist biomass) is equal to COD basis fraction of chlorophenols in the feed of the reactors as competent biomass grows on chlorophenols only. Models developed using this assumption agreed well with experimental data. The performance of a two stage rotating biological contactor (RBC) was also evaluated for the treatment of synthetic wastewater containing peptone, 4-CP and 2,4-DCP at 5 rpm. High chlorophenols (&gt / 98%) and COD (&gt / 94%) removals were achieved throughout the reactor operation up to 1000 mg/L 4-CP and 500 mg/L 2,4-DCP in the feed. Results showed that RBC is more resistant than suspended growth reactors to high chlorophenols load. The change of dominant species during the operation of SBRs and RBC was also followed using API 20NE identification kits.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-30T17:56:45Z No. of bitstreams: 1 Vanessa Schweitzer dos Santos.pdf: 1081901 bytes, checksum: 117ce960501c8c561bd7ee102cf9254a (MD5) / Made available in DSpace on 2015-06-30T17:56:45Z (GMT). No. of bitstreams: 1 Vanessa Schweitzer dos Santos.pdf: 1081901 bytes, checksum: 117ce960501c8c561bd7ee102cf9254a (MD5) Previous issue date: 2013-01-31 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / FINEP - Financiadora de Estudos e Projetos / Ministério da Ciência e Tecnologia / O lixiviado de aterro sanitário é um efluente gerado através da infiltração de águas pluviais nas camadas de cobertura do aterro e da biodegradação da fração orgânica dos resíduos sólidos urbanos aterrados. Caracteriza-se por um alto potencial poluidor e elevadas concentrações de matéria orgânica, portanto sua coleta e tratamento posterior são necessários. Sistemas biológicos podem ser aplicados no seu tratamento, visando remover matéria orgânica e nutrientes através das atividades metabólicas dos micro-organismos envolvidos no processo. Os contactores biológicos rotatórios são reatores cilíndricos que possuem em seu interior meios de suporte, onde a biomassa atua fixada, na forma de biofilme. Este entra em contato com o substrato através de rotação mecânica do tambor cilíndrico no efluente. Esta pesquisa teve como objetivo principal estudar a capacidade de remoção de matéria orgânica de lixiviado de aterro sanitário, através da utilização de um contactor biológico rotatório. O lixiviado do aterro sanitário de São Leopoldo/RS foi tratado por um contactor biológico rotatório de três estágios, que foi operado de duas formas. Uma deles foi com vazão de 8,5 L/h e tempo de retenção hidráulica de 15 h (Fase 1). Neste modo de operação a carga orgânica afluente média foi de 434 mg/L de DBO (limites entre 304 mg/L e 576 mg/L), 2484 mg/L de DQO (limites entre 882 mg/L e 3617 mg/L) e 992 mg/L de COT (limites entre 405 mg/L e 1420 mg/L). O outro modo de operação testado teve vazão de 5,1 L/h e tempo de retenção hidráulica de 24 h (Fase 2). A carga orgânica afluente média foi de 500 mg/L de DBO (limites entre 325 mg/L e 580 mg/L), 3818 mg/L de DQO (limites entre 2647 mg/L e 4764 mg/L) e 1250 mg/L de COT (limites entre 940 mg/L e 1360 mg/L). O lixiviado pesquisado apresentou como principal característica a baixa biodegradabilidade, além de ampla variação em sua composição ao longo do experimento, principalmente na Fase 1. Esta variação em sua composição pode ter afetado as eficiências de remoção de matéria orgânica, que foram de 50% de DBO, 11% de DQO e 13% de COT na Fase 1. Na Fase 2 os valores afluentes se mantiveram mais semelhantes, e as taxas de remoção de matéria orgânica foram mais constantes, além de que os valores médios de eficiência de remoção foram maiores do que os verificados na Fase 1. As eficiências de remoção na Fase 2 foram de 66% de DBO, 15% de DQO e 18% de COT. O aumento do tempo de retenção hidráulica na Fase 2 resultou em aumento da eficiência de remoção de matéria orgânica. Este efeito provavelmente está associado ao maior tempo de contato entre a biomassa e o substrato disponível no lixiviado de aterro sanitário. Quanto à remoção de matéria orgânica nos diferentes estágios do contactor biológico rotatório, foi observada uma maior eficiência nos dois primeiros estágios do sistema, principalmente dos parâmetros de DQO e COT, em ambas as fases monitoradas. Para o lixiviado e os modos de operação testados, o estágio 3 não apresentou eficiência que justifique sua presença, quanto aos parâmetros de DQO e COT. / The sanitary landfill leachate is an effluent generated by infiltration of rainwater into the layers of the landfill cover and biodegradation of the organic fraction of municipal solid waste grounded. It is characterized by a high pollution potential and high concentrations of organic matter, so their collection and further treatment is needed. Biological systems can be applied in their treatment in order to remove organic matter and nutrients through the metabolic activity of micro-organisms involved in the process. The rotating biological contactors are cylindrical reactors having inside support means, which acts fixed biomass in the form of biofilm. This comes into contact with the substrate by mechanical rotation of the cylindrical drum in the effluent. This research aimed to study the capacity of organic matter removal of landfill leachate, through the use of a rotating biological contactors. The landfill leachate São Leopoldo/RS was treated by a three-stage rotating biological contactor, which was operated in two modes. One was a flow rate of 8.5 L/h hydraulic retention time of 15 h (Phase 1). In this mode of operation the load influent organic average was 434 mg/L of BOD (limits between 304 mg/L and 576 mg/L), 2484 mg/L COD (limits between 882 mg/L and 3617 mg/L) and 992 mg/L of TOC (limits between 405 mg/L and 1420 mg/L). The other operation mode tested had a flow rate of 5.1 L/h and hydraulic retention time of 24 h (Phase 2). The average influent organic load was 500 mg/L of BOD (limits between 325 mg/L and 580 mg/L), 3818 mg/L COD (limits between 2647 mg/L and 4764 mg/L) and 1250 mg/L TOC (limits between 940 mg/L and 1360 mg/L). The researched showed landfill leachate as main characteristic the low biodegradability, and wide variation in composition throughout the experiment, especially in Phase 1. This variation in composition may have affected the removal efficiency of organic matter, which were 50% BOD, 11% COD and 13% TOC in Phase 1. In Phase 2 affluent values remained more similar, and the removal rates of organic matter were more constant, and that the average values of removal efficiency was higher than those observed in Phase 1. The removal efficiencies in Phase 2 were 66% BOD, 15% COD and 18% TOC. The increase in Phase 2 hydraulic retention time resulted in increased efficiency of removal of organic material. This effect is probably associated with greater contact time between the substrate and the biomass available in the landfill leachate. As for the removal of organic matter at different stages of rotating biological contactor, greater efficiency was observed in the first two stages of the system, particularly the parameters of COD and TOC in both phases monitored. For leachate and operating modes tested, stage 3 showed no efficiency to justify their presence, for the parameters COD and TOC.

Submitted by William Justo Figueiro (williamjf) on 2015-07-14T23:05:27Z No. of bitstreams: 1 03c.pdf: 7786125 bytes, checksum: 1e0da23c7cb679804d62aea58a41732a (MD5) / Made available in DSpace on 2015-07-14T23:05:27Z (GMT). No. of bitstreams: 1 03c.pdf: 7786125 bytes, checksum: 1e0da23c7cb679804d62aea58a41732a (MD5) Previous issue date: 2013-04-30 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / FINEP - Financiadora de Estudos e Projetos / O lixiviado gerado nos aterros caracteriza-se por conter altos teores de material orgânico recalcitrante e nutrientes com alto potencial poluidor. Diversas alternativas para o tratamento de lixiviados de aterros sanitários (LAS) têm sido amplamente estudadas obtendo-se bons resultados quanto à remoção de matéria orgânica biodegradável, porém, em sua maioria, não atingem os padrões de lançamento quanto à remoção de nutrientes. Tendo em vista a promoção de um tratamento adequado aos lixiviados e a minimização de impactos ambientais causados por este efluente, este trabalho estudou a aplicação de um contactor biológico rotatório (CBR) de 3 estágios, em escala piloto, para o tratamento de LAS. O objetivo deste trabalho foi avaliar o desempenho do CBR quanto à remoção de nitrogênio e verificar a relação desta com outros parâmetros como o TRH, razão C/N, cargas superficiais aplicadas e remoção dos compostos orgânicos. O sistema experimental foi operado com alimentação continua de lixiviado proveniente do aterro sanitário de São Leopoldo. Não foram realizados ajustes de pH e temperatura. Nas primeiras 8 semanas operou-se o sistema com um TRH de 15 h (fase 1) e nas 8 semanas subsequentes com TRH de 24h (fase 2). Como resultado, observou-se que a oxidação do nitrogênio amoniacal (NA) alcançou 94% na fase 2 de operação sendo este valor significativamente maior do que o da fase 1 onde se obteve cerca de 49% de oxidação do NA. Não foram obtidas boas remoções de orgânicos, porem observou-se uma melhora na remoção de todos os parâmetros na fase 2 de operação. Esta melhora na eficiência do sistema na fase 2 foi atribuída ao aumento de TRH. Quanto à avaliação da nitrificação no sistema, foi possível observar, na fase 2 de operação, o acúmulo de nitrito predominantemente, enquanto a concentração de nitrato no efluente final foi praticamente inexistente variando de 13 a 31 mg/L . Para as condições avaliadas por este estudo, concluiu-se que, o CBR estudado apresenta potencial para realizar a nitrificação e remoção dos compostos nitrogenados presentes no LAS. Entretanto as condições operacionais devem ser reestudadas para permitir a nitrificação total e não apenas a formação de nitrito. Da mesma forma, prover a remoção de compostos orgânicos carbonáceos. O TRH de 24h proporcionou uma melhora nas eficiências de remoção pelo sistema. Porém, para um melhor desempenho do CBR são necessárias investigações quanto aos ajustes nos parâmetros de operação que possibilitem aumentar a eficiência tanto da nitrificação quanto na remoção de matéria orgânica carbonacea. / The leachate generated in landfills is characterized by high levels of recalcitrant organic compounds and nutrients with high polluter potential. Several alternatives for the treatment of landfill leachate (LL) have been widely studied and presented good results regarding the removal of biodegradable organic matter, however, most of these systems do not reach the standards of environmental disposal of nutrients such as nitrogen compounds. Owing to promote an appropriate treatment to the leachate and minimize the environmental impacts caused by this effluent, this work studied the application of a 3 stage rotating biological contactor (RBC) in a pilot scale. The objective of this study was to evaluate the removal of nitrogen and overall performance of the RBC and check the relationship of this removal with other parameters such as the HRT, C/N ratio, ammonium and COD loads and removal of organic compounds. The experimental system was fed continuously with leachate from São Leopoldo landfill. No adjustments of pH and temperature were made. The first 8 weeks the system was operated applying an HRT of 15 h (1st period) and for the 8 subsequent weeks with HRT of 24h (2nd period). As a result, it was observed that the oxidation of ammonium nitrogen reached 94% in the 2nd period of operation which was greater than the 1st period which obtained approximately 49% of ammonium nitrogen oxidation. Low levels of organic compounds removal were obtained, however an improvement was observed in the organics removal efficiency in the 2nd period of operation. This improvement in overall efficiency of the system in the 2nd period was due to the increase of the HRT. Regarding the evaluation of nitrification in the system, in 2nd period of operation was observed the accumulation of nitrite in the system, while the concentration of nitrate in the final effluent was practically non-existent, ranging from 13 to 31 mg/L. For the conditions evaluated in this study, the conclusion was that the experimental RBC has the potential to carry out the nitrification and the removal of nitrogen compounds in the landfill leachate. Meanwhile, the operational conditions must be re-studied to allow the total nitrification and not only the formation of nitrite, as well as provide the removal of carbonaceous organic compounds. The HRT of 24h provided an improvement on removal efficiencies by the system. However, for a better performance of the RBC, investigations are necessary concerning adjustments in the operational parameters that increase efficiency of nitrification and removal of organic matter.

Made available in DSpace on 2016-06-02T19:55:27Z (GMT). No. of bitstreams: 1 3088.pdf: 1908678 bytes, checksum: ed9e01a2e9fbc1d3d2e81b225596705b (MD5) Previous issue date: 2010-02-22 / This study presents the operational results of a pilot wastewater treatment plant. The assays were carried out in two phases: Phase 1 involved the operation of a rotating biological contactor (RBC), while Phase 2 involved a combined system operation of a submerged aerated biofilter (SAB) downstream from the RBC. The RBC and SAB units were assayed in the treatment of sanitary sewage. The average feeding rate was 82.9 L.h-1 and the active sludge recirculation rate when operated only with the RBC was 60% of the former. Despite being a rotating reactor, the RBC under investigation did not have biodiscs because it was used as a microbial bed, consisting of corrugated high-density polyethylene (HDPE) tubes fixed on a metal structure in the shape of a rotating reel submerged in the aeration cell at about 90% of its diameter, providing subtracting contact between tubes a 41-m2 surface area for biofilm fixation. On the other hand, the SAB, which was comprised of corrugated HDPE rings that provided a 55-m2 contact area, was employed to polish the RBC effluent only in Phase 2 when sludge recycling was interrupted at the beginning of the process. This operation, which is typical of activated sludge systems, was carried out in Phase 1 (211 days). Substrate characterization showed maximum chemical oxygen demand (COD) concentrations of 3820.8 mgL-1 (average of 1004.5 mgL-1), an indication of contamination by liquid industrial effluents. In the first stage of testing (with the RBC), the treated effluent after secondary sedimentation tank were achieved in this study, biochemical oxygen demand (BOD) removal averages of 71.3% and the COD removals of 79.6%, respectively. Among the forms of nitrogen analysis, the concentration of organic nitrogen showed the greatest reductions reaching an average maximum of 51.2% and 91.5%. In the second stage of tests (RBC followed by SAB) efficiency BOD removal achieved was 78.2%, while the COD efficiency removal was 71.6%. The removal of volatile suspended solids after BAS achieved 39.2%, whereas RBC achieved volatile suspended solids removal of 65.3%. The pilot plant also showed that the concentration of SAB in the downstream of RBC minimized the variations in concentrations of all measured parameters, related to partially or fully treated wastewater, bringing benefits not linked to removal of carbonaceous organic matter. / Este estudo apresenta os resultados da operação de uma planta piloto de tratamento biológico para águas residuárias, em testes realizados em duas fases de estudo, sendo a primeira relacionada com a operação de um reator biológico de contato (RBC) e a segunda com a operação em sistema combinado, com um biofiltro aerado submerso (BAS) à jusante do RBC. As unidades RBC e BAS foram ensaiadas no tratamento de esgoto sanitário. A vazão média de alimentação foi de 82,9 Lh-1, e vazão de recirculação de lodo ativo quando se operou somente com o RBC, fixada em cerca de 60 % dessa vazão. O RBC utilizado, apesar de rotativo, não possuía biodiscos, pois foram utilizados como leito microbiano, tubos corrugados de polietileno de alta densidade (PEAD), fixados em uma estrutura metálica com a forma de um carretel rotativo, que foi submerso na célula de aeração em aproximadamente 90 % de seu diâmetro, enquanto que o BAS, montado com anéis corrugados, de PEAD, foi utilizado como polimento do efluente do RBC somente no segundo estágio dos ensaios. A caracterização do substrato, mostrou valores de concentração da demanda química de oxigênio (DQO), máxima de 3820,8 mgL-1 (média de 1004,5 mgL-1), denotando contaminação com efluentes líquidos industriais. No primeiro estágio dos ensaios (apenas com o RBC), o efluente tratado após o decantador secundário foram alcançadas neste estudo, remoções médias de DBO de 71,3%, e remoções de DQO de 79,6 %. Dentre as formas de nitrogênio analisadas, a concentração de nitrogênio orgânico apresentou as maiores reduções atingindo média de 51,2% e máxima 91,5%. No segundo estágio dos ensaios (RBC seguido de BAS) a eficiência alcançada de DBO foi de 78,2%, enquanto a eficiência de remoção de DQO foi de 71,6%. O BAS degradou 39,2 % dos sólidos suspensos voláteis que saíram da câmara com o RBC, enquanto o RBC degradou 65,3 % dos sólidos suspensos voláteis da entrada. A planta piloto apresentou também que a operação do BAS à jusante do RBC minimizou as variações das concentrações de todos os parâmetros analisados, relacionados ao efluente parcialmente ou totalmente tratado, não trazendo benefícios ligados a remoção de matéria orgânica carbonácea. Este estudo apresenta os resultados da operação de uma planta piloto de tratamento biológico para águas residuárias, em testes realizados em duas fases de estudo, sendo a primeira relacionada com a operação de um reator biológico de contato (RBC) e a segunda com a operação em sistema combinado, com um biofiltro aerado submerso (BAS) à jusante do RBC. As unidades RBC e BAS foram ensaiadas no tratamento de esgoto sanitário. A vazão média de alimentação foi de 82,9 Lh-1, e vazão de recirculação de lodo ativo quando se operou somente com o RBC, fixada em cerca de 60 % dessa vazão. O RBC utilizado, apesar de rotativo, não possuía biodiscos, pois foram utilizados como leito microbiano, tubos corrugados de polietileno de alta densidade (PEAD), fixados em uma estrutura metálica com a forma de um carretel rotativo, que foi submerso na célula de aeração em aproximadamente 90 % de seu diâmetro, enquanto que o BAS, montado com anéis corrugados, de PEAD, foi utilizado como polimento do efluente do RBC somente no segundo estágio dos ensaios. A caracterização do substrato, mostrou valores de concentração da demanda química de oxigênio (DQO), máxima de 3820,8 mgL-1 (média de 1004,5 mgL-1), denotando contaminação com efluentes líquidos industriais. No primeiro estágio dos ensaios (apenas com o RBC), o efluente tratado após o decantador secundário foram alcançadas neste estudo, remoções médias de DBO de 71,3%, e remoções de DQO de 79,6 %. Dentre as formas de nitrogênio analisadas, a concentração de nitrogênio orgânico apresentou as maiores reduções atingindo média de 51,2% e máxima 91,5%. No segundo estágio dos ensaios (RBC seguido de BAS) a eficiência alcançada de DBO foi de 78,2%, enquanto a eficiência de remoção de DQO foi de 71,6%. O BAS degradou 39,2 % dos sólidos suspensos voláteis que saíram da câmara com o RBC, enquanto o RBC degradou 65,3 % dos sólidos suspensos voláteis da entrada. A planta piloto apresentou também que a operação do BAS à jusante do RBC minimizou as variações das concentrações de todos os parâmetros analisados, relacionados ao efluente parcialmente ou totalmente tratado, não trazendo benefícios ligados a remoção de matéria orgânica carbonácea.

Mathematical models of a nitritation: anaerobic ammonia oxidation (anammox)-coupled biofilm in a counter-diffusion hollow fiber membrane bioreactor (HFMBR) and a nitritation: anammox-coupled biofilm in a co-diffusion rotating biological contactor (RBC) were developed and implemented using AQUASIM. Four different start-up scenarios on the nitritation: anammox-coupled biofilm in an HFMBR were investigated. The supply of oxygen was simulated with the flow through the lumen of the hollow fiber membrane. For the four scenarios, two scenarios investigated the start-up when nitrite was supplied in the feed while the other two scenarios investigated when the source of nitrite was through nitritation only. The results showed that the presence of nitrite in the feed facilitated the start-up of the reactor. In addition, the results also showed that increasing oxygen flux through the membrane up to a certain ratio of ammonia flux with oxygen flux affected reactor performance by improving nitrogen removal and reducing start up time. For the nitritation: anammox-coupled biofilm in an RBC, four different process options were investigated: the number of reactors, the initial anammox (AnAOB) biomass fraction, the bulk oxygen concentration and the maximum biofilm thickness. Modeling results revealed that the steady state total nitrogen removal in RBC reactors in series occurred primarily in the first and second reactors. It is concluded that the number of reactors in series dictates the effluent performance and, therefore, this number can be selected depending upon the desired total nitrogen removal. Simulation results also revealed that increasing the initial AnAOB biomass fraction from 0.01% to 1.0% had no effect in the steady state nitrogen removal but had an effect in the required time to reach the steady state total nitrogen removal and the maximum biofilm thickness. Modeling results of the third process option showed that increasing the bulk oxygen concentration in the reactor from 0.2 g/m3 to 5 g/m3 linearly increased the steady state total nitrogen removal and reduced the time to reach the maximum biofilm thickness. Beyond 5 g/m3, steady state total nitrogen removal decreased. In addition, simulation results revealed that the thicker biofilm clearly showed a more linear correlation between the increase in bulk oxygen concentration and the increase in the steady state total nitrogen removal within a range of bulk oxygen concentrations. The results showed that RBC performance could be controlled by several process options: the number of reactors in series, initial biomass fraction, the bulk oxygen concentration and the maximum biofilm thickness. The mathematical modeling results for the HFMBR and RBC have shown that both have potential as carriers for nitritation: anammox-coupled biofilms targeted at the removal of nitrogen in the wastewater. / Master of Science

Le développement de biofilms est étudié sur de longues périodes (de deux à sept mois) dans des réacteurs à disque tournant (RBC) et à lit fixe alimentés par des eaux résiduaires domestiques ou des substrats synthétiques en continu à l’échelle du laboratoire. Deux réacteurs ont été spécialement conçus pour des expériences. Les biofilms ont été soumis à des stress physiques (forces hydrodynamiques) ou chimiques (antibiotique). L’activité biologique des réacteurs a été suivie au cours du temps (dégradation de la pollution carbonée et azotée). Les phénomènes de détachement et de redéveloppement des biofilms ont été caractérisés sur des surfaces lisses ou structurées par des techniques d’analyse d’images non destructives. La quantité globale de biomasse présente est évaluée par l’opacité du biofilm et cette méthode d’évaluation a été validée par comparaison avec des méthodes classiques destructives (coloration au Cristal Violet, matières sèches). La macrostructure du biofilm, liées aux phénomènes de croissance, détachement et recroissance, a été évaluée à l’aide de deux méthodes de caractérisation de la texture visuelle : la méthode de cooccurrence de niveaux de gris (SGLDM) et la longueur des segments (GLRLM). Le travail montre l’efficacité de l’analyse d’images comme une méthode rapide et peu onéreuse dans l’étude des biofilms sur le long terme. / The development of biofilm has been studied over long periods of time (two to seven months) in laboratory-scale rotating biological contactors and fixed bed reactors continuously fed with municipal wastewater or synthetic growth media. Two reactors have been specifically designed for this purpose. The biofilms have been subject to hydrodynamic and chemical (antibiotics) stresses. The overall biological activity of the reactors have been monitored, in terms of carbon and nitrogen removal. The phenomena of sloughing and re-growth have been characterized on smooth and rough surfaces using image analysis non-destructive techniques. The amount of biomass present on the substratum has been evaluated by the biofilm opacity and this monitoring method has been validated by comparison with destructive methods such as crystal violet staining and dry weight. The biofilm macrostructure, related to growth, sloughing and re-growth phenomena, has been evaluated through visual texture characterization of the scanning gray level co-occurrence matrix (SGLDM) and the gray level run length method (GLRLM). The results shows the efficiency of image analysis as a rapid and cheap method to monitor biofilm development on the long term.