O tratamento do lodo gerado em estações de tratamento de água para abastecimento (ETAs) é uma questão a ser equacionada em todo o território nacional. O tratamento desses lodos em estações de tratamento de esgoto (ETEs) é uma alternativa a ser estudada, pois pode levar a uma solução eficaz e de custos reduzidos se compararmos aos custos de implantação e operação de um sistema de tratamento de lodos nas próprias ETAs. O recebimento de lodo de ETAs em ETEs é feito em algumas ETEs dos Estados Unidos, porém no Brasil ainda são escassos estudos específicos para sanar as questões técnicas envolvidas tanto na etapa aeróbia quanto na anaeróbia. O sistema de tratamento de esgotos por lodos ativados utilizando mídia plástica como meio suporte ao crescimento microbiológico é outro atrativo ao recebimento de lodo de ETA em uma ETE, visto que estudos demonstram que este tipo de variante é capaz de tratar maior carga orgânica, sem sofrer qualquer inibição de processo. O presente estudo avaliou o recebimento de até 400 mg de SST de lodo de ETA por litro de esgoto em um sistema utilizando mídia plástica como meio suporte. O lodo de ETA utilizado foi proveniente de sistemas que utilizaram sais de Ferro e de Alumínio em seus processos. Não foi observada qualquer inibição no processo aeróbio quanto à remoção de matéria orgânica ou nitrogenada com o recebimento de lodo de ETA em qualquer concentração e operando um sistema com mídia plástica. A carga de DBO5,20 aplicada ao reator biológico ficou entre 1,7 a 15,3 gDBO5,20/m²/dia, e a concentração média da DBO 5,20 no efluente final esteve em todo o período do experimento em 34 mg/L. Com a utilização da mídia plástica o processo de nitrificação teve taxas de remoção passando de 0,9 gNKT/m²/dia para 1,7 gNKT/m²/dia, portanto aumento de 95%. A avaliação do lodo gerado no decantador primário da ETE Piloto demonstra que houve alteração em sua composição, principalmente na relação de SV/ST e o aumento na concentração de metais, principalmente o elemento Ferro. Estas características podem levar à inibição o processo anaeróbio. O teste de Atividade Metanogênica Especifica (AME) realizada com dosagens de 0,4 g e 0,8 g de ST de lodo de ETA demonstra que há inibição da metanogênese para concentrações acima de 0,4 g de ST. A concentração na qual não se observou efeito negativo corresponde a 10% da quantidade mássica que o digestor anaeróbio foi alimentado. Porém o teste de AME reproduz toxicidade aguda, não considerando a possível adaptação que pode ocorrer ou mesmo demonstrar que um esgoto que, em primeira análise é considerado biodegradável, tem na realidade toxicidade crônica. A operação do sistema utilizando mídia plástica levou a uma redução na produção de lodo na ordem de 57%. Antes da maturação do biofilme a produção era de 0,19 g SSV/g DQO removida e passou para 0,09 g SSV/g DQO removida. / An issue to be taken into account, regarding the continental size of the country is the sludge treatment generated in water treatment plants (WTPs). The treatment of the aforementioned sludge which is held in water treatment plant (WWTP) is a valid alternative considering its costs and efficacy as opposed to the budgetary considerations for the sludge treatment in the WTPs alone. The recipience of the sludge from WTP into WWTPs, is done by some North Americans WWTPs, in Brazil, nonetheless, such specific studies are of short supply to heal the technical questions regarding both the anaerobic and also the aerobic processes. The activated sludge operational swage system with plastic medium as means to aid the microbiologic development, also entices the reception of sludge from WTP into WWTPs, given the fact that some studies have demonstrated this variant type capable of treating a much bigger organic load not even suffering any inhibition over the process. This current study evaluated the reception of a sum up to 400 mg (milligrams) of sludge TSS by sewage liter in a plastic medium as means to aid such process. The sludge from WTP used in here came from systems which utilized Iron and aluminum salt in their processes. Any inhibition regarding the removal of organic or nitrogenated matter in the aerobic process operated with the plastic medium system with the reception of sludge from WTP was observed and/or noticed The BOD5,20 charge which was applied to the biological reactor ranked between 1,7 to 15,3 gDBO5,20/m²/day, and the BOD5,20 average concentration into the final effluent was all the time the experiment was going on in 34 mg/L. Regarding the usage of plastic medium over the nitrification process, removal which jumped from 0,9 gNKT/m²/day to 1,7 gNKT/m²/day, thus an increase of 95%. The evaluation of the sludge generated from the WWTPs primary settling tank demonstrates alteration in its composition, mainly related to VS/TS and the metal concentration augmentation, iron being the most present element in here. Such characteristics may lead to an inhibition regarding the anaerobic process. The specific methanogenic activity (SMA) taking into account the dosages: 0, 4 g and 0, 8 g of TS sludge from WTP shows methanogenesis inhibition for concentrations superior to 0, 4 g of TS. 10% of mass quantity is the amount which no negative effect was noticed when feeding the anaerobic digestor. The SMA test, however, reproduces acute toxicity, not taking into account the possible adaptation that may occur or even demonstrate that the sewage which at first instance could be considered biodegradable is in its real sense chronically toxic. The activated sludge operating with plastic medium has lead the sludge production to reduction of around 57%, before the biofilm maturation the production was 0,19 g VSS/g COD removed and it was upgraded to 0,09 g VSS/g COD removed.

Esta pesquisa buscou avaliar a secagem e higienização em estufa agrícola de excesso de lodo ativado gerado em Estações de Tratamento de Esgoto que tratam esgoto doméstico, localizadas na Região Metropolitana da Grande Vitória, Espírito Santo e, à partir dos resultados, estimar a área e o custo de investimento necessários para a instalação da estufa. A intenção foi atingir os padrões para lodo Classe A (Resolução no 375/2006 do Conama), que possibilita o uso do material na agricultura. A estufa possuía cobertura e revestimento lateral em lona plástica translúcida para impedir a penetração de água e possibilitar a penetração da radiação solar. O estudo foi dividido em duas etapas, ou seja, num primeiro momento, houve a avaliação do lodo digerido aerobiamente, com e sem cal, e, num segundo, a do lodo não encaminhado ao digestor, com e sem cal. Cada etapa era composta de três ciclos (repetições) com procedimentos metodológicos diferenciados e tempo de duração aproximado de 70 dias. Com o monitoramento temporal dos parâmetros estudados em cada ciclo, foi possível avaliar e definir a melhor configuração para a otimização da técnica estudada. As concentrações de substâncias inorgânicas no lodo usado na pesquisa já se apresentavam com valores bem inferiores aos padrões do Conama. Os parâmetros de interesse agronômico monitorados apresentaram valores atraentes sob o aspecto agronômico. Com relação aos vírus, os resultados apresentados foram inconclusivos e, em face disso, os resultados não foram usados nas considerações finais acerca do processo utilizado. Diante dos resultados obtidos, é razoável afirmar que entre as condições metodológicas testadas, a melhor configuração para o uso da estufa agrícola na secagem e higienização do lodo, atendendo aos padrões para lodo Classe A (exceto vírus), foi: tempo de secagem aproximado de 36 dias; forma de disposição do lodo com altura igual a 10cm; período de revolvimento de três vezes por semana; lodo sem adição de cal. Essa configuração possibilita obter um biossolido com umidade final de, aproximadamente, 25%, resultando numa diminuição do volume bastante expressiva, de cerca de 76%. As estimativas de dimensão e custo, também foram realizadas. / This research aimed at assessing the dry and hygienization in a greenhouse excess of the activated sludge generated in Wastewater Treatment Plants that treats domestic sewage, located in the Metropolitan Region of the Great Vitória, Espírito Santo, and from the results, estimate the area and the cost of investment required for installation from the greenhouse. The intention was to meet the standards defined for sludge Class A (375/2006 Resolution of Conama) which enable the use of the material in the agriculture. The greenhouse had coverage and coating side canvas translucent plastic to prevent the ingress of water and allow the penetration of solar radiation. The study was divided into two stages, i.e. first, there was an assessment of the aerobically digested sludge behavior and, with and without lime, and second, the sludge which was not sent to the digester, with and without lime. Each part was composed by three cycles (repetitions) with differentiated methodological procedures and time of duration approximately of 70 days in order to evaluate the best configuration for the optimization of the studied technique. The concentrations of inorganic substances in the utilized sludge in the research were already presented with much lower values in relation to the standards of Conama. The parameters of monitored agricultural interest show interesting values under an agricultural aspect. In relation to virus, the presented results were inconclusive. Therefore, they were not used in the final considerations in relation to the utilized process. In face of the obtained results, it is reasonable to state that among the tested methodological conditions, the best configuration for the use of agricultural greenhouse in the dry and hygienization of the sludge, meeting the standards for the sludge Class A (except virus) was: the time of dry approximately 36 days; form of sludge disposition with 10 cm height; revolving period of 3 times a week; sludge without the addition of lime. With this configuration, it is possible to obtain a biosolid with moisture of approximately 25% resulting in a very expressive decreasing of volume, around 76%. Estimates of the size and cost were also performed.

Este trabalho de pesquisa teve por objetivo avaliar o efeito do descarte de lodo aeróbio no desempenho do reator UASB. Em paralelo, foi verificado o efeito dessa operação na qualidade do efluente final da ETE, no desempenho operacional da unidade de pós-tratamento e nas características do biogás produzido no reator UASB. De modo geral, não houve impacto negativo no processo de digestão anaeróbia em termos de DQO filtrada no efluente, que foi semelhante quando o afluente era composto essencialmente de esgoto bruto, na ordem de 60 a 80 mg/L. Por outro lado, os resultados indicaram uma tendência de redução da qualidade do efluente do reator UASB em termos de DQO total e sólidos em suspensão, quando da alimentação desse reator com excesso de lodo aeróbio. Em 2016, a concentração média de DQO total no efluente foi da ordem de 529 mg/L e a concentração média de SST foi na ordem de 672 mg/L quando o afluente do reator UASB era composto com excesso de lodo aeróbio, ao passo que, sem excesso de lodo aeróbio no afluente, a DQO total média no efluente foi de 269 mg/L e a concentração média de SST foi de 349 mg/L. Porém, essa redução da qualidade pareceu estar relacionada a uma sobreposição de efeitos associado a presença de lodo aeróbio no afluente, e a sistemática adotada na estação para remoção de lodo anaeróbio do reator UASB. Quando não havia remoção de excesso de lodo anaeróbio de fundo do reator UASB, a qualidade do efluente se manteve durante a maior parte do tempo monitorado compatível com os períodos onde o afluente do reator UASB era composto essencialmente de esgoto bruto, indicando que o lodo de fundo, mais concentrado, exerce papel fundamental na retenção do lodo aeróbio na zona de digestão do reator UASB. Essa constatação se mostrou mais explícita quando as operações de descarte de excesso de lodo aeróbio e remoção de lodo anaeróbio do reator UASB ocorriam em períodos distintos. Nessa condição, a concentração média de DQO total no efluente foi de 254 mg/L e a concentração média de SST foi de 314 mg/L, ao passo que sem lodo aeróbio no afluente do reator UASB, a concentração média de DQO total no efluente foi de 191 mg/L e a concentração de SST foi de 258 mg/L. As características do biogás produzido variaram quando o sistema era alimentado com excesso de lodo aeróbio no afluente, apresentando, nessa condição, maior concentração de CO2 e menor concentração de H2S. Não houve, alteração da concentração média de metano quando da presença de excesso de lodo aeróbio no afluente. Outro aspecto observado foi a falta de correlação entre os parâmetros DQO removida e produção volumétrica de biogás quando o afluente do reator UASB continha excesso de lodo aeróbio. Na ausência de excesso de lodo aeróbio no afluente, houve correlação entre essas variáveis, porém uma correlação fraca, na ordem de 0,40, que pode ser explicada por uma captação ineficaz do biogás produzido, devido a vazamentos pela linha de quebra-escuma do separador trifásico, e por perdas de metano dissolvido com o efluente. Com relação ao impacto na unidade de pós-tratamento, a baixa capacidade de remoção de lodo de excesso da ETE devido a dificuldades de ordem operacional e contratual, condicionaram a operação do sistema de lodo ativado com elevadas concentrações de sólidos em suspensão. Nessa condição, o sistema de aeração apresentou baixa eficiência de transferência de oxigênio para o licor misto, o que impactou negativamente no consumo de energia elétrica do processo de lodo ativado, aumentando o custo operacional da ETE. A qualidade do efluente final da ETE, de modo geral, não foi impactada pela operação de descarte de lodo aeróbio no reator UASB, tendo mantido durante a maior parte do tempo DQO média na ordem de 40 mg/L no efluente e concentração de sólidos em suspensão totais em média na ordem de 25 mg/L. A nitrificação e desnitrificação foi variável ao longo do período do estudo, sendo que o processo apresentou eficiência média de remoção de nitrogênio em torno de 66%. / The objective of this research was to evaluate the effect of aerobic sludge discard on UASB reactor performance. In parallel, the effect of this operation on the final effluent quality of the WWTP, the operational performance of the post-treatment plant and the characteristics of the biogas produced in the UASB reactor were verified. In general, there was no negative impact on the anaerobic digestion process in terms of dissolved COD in the effluent, which was similar when the influent was composed essentially of raw sewage, in the order of 60 to 80 mg / L. On the other hand, the results indicated a tendency to reduce the quality of the UASB reactor effluent in terms of total COD and suspended solids when feeding this reactor also with excess aerobic sludge. In 2016, the mean concentration COD in the effluent was of the order of 529 mg / L and the mean concentration SST was 672 mg / L when the UASB reactor inflow was composed of excess aerobic sludge, while, without excess of aerobic sludge in the influent, the mean COD in the effluent was 269 mg / L and the mean concentration of SST was 349 mg / L. However, this quality reduction seemed to be related to an overlap of effects associated with the presence of aerobic sludge in the influent, and the system adopted at the WWTP to remove anaerobic sludge from the UASB reactor. When there was no removal of excess anaerobic bottom sludge from the UASB reactor, the quality of the effluent remained for most of the monitored time consistent with the periods where the UASB reactor inflow was essentially composed of raw sewage, indicating that the sludge from deep, more concentrated, plays a fundamental role in the retention of aerobic sludge in the digestion zone of the UASB reactor. This finding was more explicit when the operations of excess aerobic sludge and anaerobic sludge removal from the UASB reactor occurred at different periods. In this condition, the mean COD concentration in the effluent was 254 mg / L and the mean SST concentration was 314 mg / L, whereas without aerobic sludge in the UASB reactor, the mean total COD concentration in the effluent was 191 mg / L and the concentration of SST was 258 mg / L. The characteristics of the biogas produced varied when the system was fed with excess of aerobic sludge in the influent presenting, in this condition, a higher concentration of CO2 and a lower concentration of H2S. There was, fortunately, no change in the average concentration of methane when there was an excess of aerobic sludge in the influent. Another important aspect observed was the lack of correlation between the COD removal parameters and volumetric biogas production when the UASB reactor inflow contained excess aerobic sludge. In the absence of excess aerobic sludge in the influent, there was a correlation between these variables, but a weak correlation, in the order of 0.40, which can be explained by an inefficient capture of the biogas produced, due to leaks by the three-phase separator, and for losses of methane dissolved with the effluent. Regarding the impact on the post-treatment unit, the low sludge removal capacity of the WWTP due to operational and contractual difficulties, conditioned the operation of the activated sludge system with high concentrations of suspended solids. In this condition, the aeration system presented low oxygen transfer efficiency for the mixed liquor, which negatively impacted the electric power consumption of the activated sludge process, increasing the operational cost of the WWTP. The final effluent quality, in general, was not affected by the aerobic sludge discharge operation in the UASB reactor, having maintained for the most part the average COD in the order of 40 mg / L in the effluent and the solids concentration in suspension on average in the order of 25 mg / L. Nitrification and denitrification were variable throughout the study period, with the average nitrogen removal efficiency around 66%.

Esta pesquisa buscou avaliar a secagem e higienização em estufa agrícola de excesso de lodo ativado gerado em Estações de Tratamento de Esgoto que tratam esgoto doméstico, localizadas na Região Metropolitana da Grande Vitória, Espírito Santo e, à partir dos resultados, estimar a área e o custo de investimento necessários para a instalação da estufa. A intenção foi atingir os padrões para lodo Classe A (Resolução no 375/2006 do Conama), que possibilita o uso do material na agricultura. A estufa possuía cobertura e revestimento lateral em lona plástica translúcida para impedir a penetração de água e possibilitar a penetração da radiação solar. O estudo foi dividido em duas etapas, ou seja, num primeiro momento, houve a avaliação do lodo digerido aerobiamente, com e sem cal, e, num segundo, a do lodo não encaminhado ao digestor, com e sem cal. Cada etapa era composta de três ciclos (repetições) com procedimentos metodológicos diferenciados e tempo de duração aproximado de 70 dias. Com o monitoramento temporal dos parâmetros estudados em cada ciclo, foi possível avaliar e definir a melhor configuração para a otimização da técnica estudada. As concentrações de substâncias inorgânicas no lodo usado na pesquisa já se apresentavam com valores bem inferiores aos padrões do Conama. Os parâmetros de interesse agronômico monitorados apresentaram valores atraentes sob o aspecto agronômico. Com relação aos vírus, os resultados apresentados foram inconclusivos e, em face disso, os resultados não foram usados nas considerações finais acerca do processo utilizado. Diante dos resultados obtidos, é razoável afirmar que entre as condições metodológicas testadas, a melhor configuração para o uso da estufa agrícola na secagem e higienização do lodo, atendendo aos padrões para lodo Classe A (exceto vírus), foi: tempo de secagem aproximado de 36 dias; forma de disposição do lodo com altura igual a 10cm; período de revolvimento de três vezes por semana; lodo sem adição de cal. Essa configuração possibilita obter um biossolido com umidade final de, aproximadamente, 25%, resultando numa diminuição do volume bastante expressiva, de cerca de 76%. As estimativas de dimensão e custo, também foram realizadas. / This research aimed at assessing the dry and hygienization in a greenhouse excess of the activated sludge generated in Wastewater Treatment Plants that treats domestic sewage, located in the Metropolitan Region of the Great Vitória, Espírito Santo, and from the results, estimate the area and the cost of investment required for installation from the greenhouse. The intention was to meet the standards defined for sludge Class A (375/2006 Resolution of Conama) which enable the use of the material in the agriculture. The greenhouse had coverage and coating side canvas translucent plastic to prevent the ingress of water and allow the penetration of solar radiation. The study was divided into two stages, i.e. first, there was an assessment of the aerobically digested sludge behavior and, with and without lime, and second, the sludge which was not sent to the digester, with and without lime. Each part was composed by three cycles (repetitions) with differentiated methodological procedures and time of duration approximately of 70 days in order to evaluate the best configuration for the optimization of the studied technique. The concentrations of inorganic substances in the utilized sludge in the research were already presented with much lower values in relation to the standards of Conama. The parameters of monitored agricultural interest show interesting values under an agricultural aspect. In relation to virus, the presented results were inconclusive. Therefore, they were not used in the final considerations in relation to the utilized process. In face of the obtained results, it is reasonable to state that among the tested methodological conditions, the best configuration for the use of agricultural greenhouse in the dry and hygienization of the sludge, meeting the standards for the sludge Class A (except virus) was: the time of dry approximately 36 days; form of sludge disposition with 10 cm height; revolving period of 3 times a week; sludge without the addition of lime. With this configuration, it is possible to obtain a biosolid with moisture of approximately 25% resulting in a very expressive decreasing of volume, around 76%. Estimates of the size and cost were also performed.

O tratamento do lodo gerado em estações de tratamento de água para abastecimento (ETAs) é uma questão a ser equacionada em todo o território nacional. O tratamento desses lodos em estações de tratamento de esgoto (ETEs) é uma alternativa a ser estudada, pois pode levar a uma solução eficaz e de custos reduzidos se compararmos aos custos de implantação e operação de um sistema de tratamento de lodos nas próprias ETAs. O recebimento de lodo de ETAs em ETEs é feito em algumas ETEs dos Estados Unidos, porém no Brasil ainda são escassos estudos específicos para sanar as questões técnicas envolvidas tanto na etapa aeróbia quanto na anaeróbia. O sistema de tratamento de esgotos por lodos ativados utilizando mídia plástica como meio suporte ao crescimento microbiológico é outro atrativo ao recebimento de lodo de ETA em uma ETE, visto que estudos demonstram que este tipo de variante é capaz de tratar maior carga orgânica, sem sofrer qualquer inibição de processo. O presente estudo avaliou o recebimento de até 400 mg de SST de lodo de ETA por litro de esgoto em um sistema utilizando mídia plástica como meio suporte. O lodo de ETA utilizado foi proveniente de sistemas que utilizaram sais de Ferro e de Alumínio em seus processos. Não foi observada qualquer inibição no processo aeróbio quanto à remoção de matéria orgânica ou nitrogenada com o recebimento de lodo de ETA em qualquer concentração e operando um sistema com mídia plástica. A carga de DBO5,20 aplicada ao reator biológico ficou entre 1,7 a 15,3 gDBO5,20/m²/dia, e a concentração média da DBO 5,20 no efluente final esteve em todo o período do experimento em 34 mg/L. Com a utilização da mídia plástica o processo de nitrificação teve taxas de remoção passando de 0,9 gNKT/m²/dia para 1,7 gNKT/m²/dia, portanto aumento de 95%. A avaliação do lodo gerado no decantador primário da ETE Piloto demonstra que houve alteração em sua composição, principalmente na relação de SV/ST e o aumento na concentração de metais, principalmente o elemento Ferro. Estas características podem levar à inibição o processo anaeróbio. O teste de Atividade Metanogênica Especifica (AME) realizada com dosagens de 0,4 g e 0,8 g de ST de lodo de ETA demonstra que há inibição da metanogênese para concentrações acima de 0,4 g de ST. A concentração na qual não se observou efeito negativo corresponde a 10% da quantidade mássica que o digestor anaeróbio foi alimentado. Porém o teste de AME reproduz toxicidade aguda, não considerando a possível adaptação que pode ocorrer ou mesmo demonstrar que um esgoto que, em primeira análise é considerado biodegradável, tem na realidade toxicidade crônica. A operação do sistema utilizando mídia plástica levou a uma redução na produção de lodo na ordem de 57%. Antes da maturação do biofilme a produção era de 0,19 g SSV/g DQO removida e passou para 0,09 g SSV/g DQO removida. / An issue to be taken into account, regarding the continental size of the country is the sludge treatment generated in water treatment plants (WTPs). The treatment of the aforementioned sludge which is held in water treatment plant (WWTP) is a valid alternative considering its costs and efficacy as opposed to the budgetary considerations for the sludge treatment in the WTPs alone. The recipience of the sludge from WTP into WWTPs, is done by some North Americans WWTPs, in Brazil, nonetheless, such specific studies are of short supply to heal the technical questions regarding both the anaerobic and also the aerobic processes. The activated sludge operational swage system with plastic medium as means to aid the microbiologic development, also entices the reception of sludge from WTP into WWTPs, given the fact that some studies have demonstrated this variant type capable of treating a much bigger organic load not even suffering any inhibition over the process. This current study evaluated the reception of a sum up to 400 mg (milligrams) of sludge TSS by sewage liter in a plastic medium as means to aid such process. The sludge from WTP used in here came from systems which utilized Iron and aluminum salt in their processes. Any inhibition regarding the removal of organic or nitrogenated matter in the aerobic process operated with the plastic medium system with the reception of sludge from WTP was observed and/or noticed The BOD5,20 charge which was applied to the biological reactor ranked between 1,7 to 15,3 gDBO5,20/m²/day, and the BOD5,20 average concentration into the final effluent was all the time the experiment was going on in 34 mg/L. Regarding the usage of plastic medium over the nitrification process, removal which jumped from 0,9 gNKT/m²/day to 1,7 gNKT/m²/day, thus an increase of 95%. The evaluation of the sludge generated from the WWTPs primary settling tank demonstrates alteration in its composition, mainly related to VS/TS and the metal concentration augmentation, iron being the most present element in here. Such characteristics may lead to an inhibition regarding the anaerobic process. The specific methanogenic activity (SMA) taking into account the dosages: 0, 4 g and 0, 8 g of TS sludge from WTP shows methanogenesis inhibition for concentrations superior to 0, 4 g of TS. 10% of mass quantity is the amount which no negative effect was noticed when feeding the anaerobic digestor. The SMA test, however, reproduces acute toxicity, not taking into account the possible adaptation that may occur or even demonstrate that the sewage which at first instance could be considered biodegradable is in its real sense chronically toxic. The activated sludge operating with plastic medium has lead the sludge production to reduction of around 57%, before the biofilm maturation the production was 0,19 g VSS/g COD removed and it was upgraded to 0,09 g VSS/g COD removed.

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.

Advanced wastewater treatment plants have complex biological kinetics, time variant influent rates and long processing times. The modeling and operation control of wastewater treatment plant gets complicated due to these characteristics. However, a robust operational system for a wastewater treatment plant is necessary to increase the efficiency of the plant, reduce energy cost and achieve environmental discharge limits. These discharge limits are set by the National Pollutant Discharge Elimination System (NPDES) for municipal and industrial wastewater treatment plants to limit the amount of nutrients being discharged into the aquatic systems. This document summarizes the research to develop a supervisory operational and control system for the Valrico Advanced Wastewater Treatment Plant (AWWTP) in the Hillsborough County, Florida. The Valrico AWWTP uses biological treatment process and has four oxidation ditches with extended aeration where simultaneous nitrification and denitrification (SND) takes place. Each oxidation ditch has its own anaerobic basin where in the absence of oxygen, the growth of microorganisms is controlled and which in return also helps in biological phosphorus removal. The principle objective of this research was to develop a working model for the Valrico AWWTP using BioWin which mimics the current performance of the plant, predicts the future effluent behavior and allows the operators to take control actions based on the effluent results to maintain the discharge permit limits. Influent and experimental data from online and offline sources were used to tune the BioWin model for the Valrico Plant. The validation and optimization of the BioWin model with plant data was done by running a series of simulations and carrying out sensitivity analysis on the model which also allowed the development of operation policies and control strategies. The control strategies were developed for the key variables such as aeration requirements in the oxidation ditch, recycle rates and wastage flow rates. A controller that manipulates the wasting flow rate based on the amount of mixed liquor suspended solids (MLSS) was incorporated in the model. The objective of this controller was to retain about 4500-4600 mg/L of MLSS in the oxidation ditch as it is maintained by the Valrico Plant. The Valrico AWWTP recycles around 80% of their effluent and hence, the split ratios were adjusted accordingly in the model to recycle the desired amount. The effluent concentrations from the BioWin model for the parameters such as Total Nitrogen (TN), Ammonia, Nitrate, Nitrite, Total Kjeldahl Nitrogen (TKN) complied with the discharge limits which is usually less than 2 mg/L for all the parameters.

Bibliography: leaves 256-275.

Slamsvällning orsakar stora problem i avloppsreningsverk med biologisk rening i aktivt slamprocesser. Slamsvällning orsakas av filamentösa (trådformiga) bakterier, som inverkar negativt på slammets sedimenteringsegenskaper. Himmerfjärdens vattenreningsverk har drabbats av detta problem som leder till ett stabilt lager av slam på ytan av sedimenteringsbassängen som inte sedimenterar. För att lösa detta problem behandlades returslammet från sedimenteringsbassängen med ozon för att minska mängden filamentösa bakterier i returslamflödet. Ozon är en starkt oxiderande gas, som är väl användbar för icke-specifik bekämpning av slamsvällning. När ozon kommer i kontakt med den filamentösa bakteriens cellvägg penetreras det in i cellen, varvid cellen lyserar. Ozonbehandlingen resulterade i en förminskning av antalet filamentösa bakterier. Ozonbehandling av returslam förbättrade sedimenteringsegenskaperna hos svällande slam utan att påverka andra viktiga mikrobiologiska processer t.ex. nitrifikation. / Bulking sludge causes major problems in wastewater treatment plants that deal with biological nutrient removal in activated sludge processes. Bulking sludge is caused by filamentous bacteria, which have a negative impact on the sludge settling properties. Himmerfjärden wastewater treatment plant suffers from this type of problem with bulking sludge which creates a stable layer at the surface that does not settle in the clarifier. In order to solve this problem, on site generated ozone was used to decrease the amount of filamentous bacteria in the return activated sludge flow. Ozone is a strong oxidant is suitable for non-specific bulking control. It stresses the filamentous bacteria causing inactivation through cell wall disintegration. The ozone treatment resulted in decreased abundance of filamentous bacteria. Ozone treatment of the recycled activated sludge improves the settling properties of bulking sludge, without interfering with other important microbiological processes e.g. nitrification.

The activated sludge process efficiency depends on separation of microbial cells from treated wastewater. Separation can fail due to a number of problems. One of these problems is sludge bulking which is non-settling situation of biomass. Former studies showed that phosphorus deficiency caused filamentous sludge bulking with increasing magnesium ion concentrations. The main objectives of this study are to find out the effect of magnesium ions on sludge properties in phosphorus deficient medium and to determine if there is any bulking. Three different concentrations of magnesium (0.5, 5, 15 meq/L) were added to three bioreactors which contained phosphorus deficient medium. In first set C: N: P ratio was 100:5:0.05. In second set, C:N:P ratio was elevated to 100:5:1. At steady state, physical characteristics including sludge volume index (SVI), viscosity, turbidity and dewaterability were determined. Besides concentration of extracellular polymeric substances (EPS) as well as conductivity was measured. By using API kits, bacterial identification was achieved. In first set phosphorus deficiency and increasing magnesium ion concentration caused filamentous bulking. Carbohydrate content of extracellular polymeric substance significantly increased by magnesium addition. Dewaterability of the system got worse and viscosity decreased. Sludge Volume Index (SVI) indicated severe bulking at all magnesium concentrations. By using biochemical tests microorganisms dominant in the system were determined In second set, all of the parameters indicated healthy flocculation. By magnesium addition, EPSp and EPSc increased. Dewaterability and settleability, improved by the presence of phosphorus with close values measured at different magnesiuim concentrations. Nocardia related genera of Corynebacterium and Enteric microorganisms were identified.