A presente pesquisa teve como objetivo a avaliação do uso da banda de rodagem de pneus inservíveis triturada (BPIT) como suporte ao desenvolvimento de biofilmes em um reator anaeróbio de leito expansível (RALEx), em escala plena, com volume de 32m3, empregado no tratamento de esgoto sanitário. A utilização desse material como suporte apresentou-se como proposta inovadora, com grande potencial de aplicação. Para partida do sistema foram utilizados 6,0m3 de lodo proveniente do reator UASB da Estação de Tratamento de Esgoto Jardim das Flores de Rio Claro – SP, tendo sido alcançado o equilíbrio dinâmico aparente após 80 dias de operação. A BPIT mostrou-se eficiente como recheio do RALEx, tendo em vista que promoveu remoção média de 70% de matéria orgânica, em termos de DBO (amostras não filtradas), quando operado com tempo de detenção hidráulico médio de 3,2h, velocidade ascensional média de 5,7m/h (sem recirculação do efluente), e carga orgânica volumétrica média de 5,4kgDQO/m3.dia. A remoção média de sólidos em suspensão no sistema foi de 65% (com teor residual no efluente de 95mg/L) e a porcentagem de metano no biogás manteve-se próxima a 65%. Assim como os demais reatores anaeróbios, verificou-se que a remoção de nitrogênio e fósforo no RALEx foi relativamente baixa, com valores inferiores a 10%. Avaliou-se também a perda de carga no leito de BPIT, obtendo-se valores extremamente baixos para todas as granulometrias testadas, em torno de 4cm/m de leito, e determinou-se a velocidade mínima de fluidificação em 39m/h. Nos ensaios preliminares, verificou-se que o diâmetro equivalente das partículas de BPIT foi de 4,3mm, com coeficiente de desuniformidade de 1,61 e massa específica de 1,14g/cm3. A BPIT mostrou-se competitiva também no aspecto econômico, tendo em vista que o custo de aquisição foi 12,8 vezes inferior ao do carvão ativado granular e 1,6 vezes superior ao da areia (materiais comumente utilizados como recheio de RALEx). / The present research had as objective the assessment of granulated tread of scrap tires (GTST) as support for the development of biofilms in an expanded bed anaerobic reactor (EBAR), in full scale, with a total volume of 32m3, employed for wastewater treatment. The use of this material as support was presented as an innovating proposal, with a high application potential. To start up the system 6.0m3 of sludge coming from the UASB reactor from Jardim das Flores Wastewater Treatment Plant, Rio Claro – SP, were used. The apparent dynamic equilibrium was reached 80 days after operating start up. GTST showed itself as efficient in the packing of the EBAR, where it removed an average of 70% of organic matter, in terms of BOD (non-filtered samples), when operated with hydraulic detention time of 3.2h, mean ascension velocity of 5.7m/h (without effluent re-circulation), and mean volumetric organic load of 5.4kgCOD/m3.day. The mean suspended solids removal in the system was of 65% (with 95mg/L of residual content in the effluent) and the percent of methane in biogas was close to 65%. Likewise in other anaerobic reactors, it was seen that nitrogen and phosphorous removal in the EBAR was relatively low, with values below 10%. Headloss was also assessed in the bed of the GTST, where extremely low values were obtained for all tested granulometry, around 4cm/m in the bed. In the preliminary essays, it was verified that the equivalent diameter of GTST particles was of 4.3mm, with disuniformity coefficient of 1.61 and specific mass of 1.14g/cm3. GTST was also competitive in the economical aspect, where the acquisition cost was 12.8 times lower than granular activated carbon and 1.6 times higher than sand (materials commonly used as EBAR packing material).

O processamento anaeróbio da vinhaça se apresenta como uma alternativa para a recuperação de energia (biogás), e reaproveitamento das suas características nutricionais através da disposição no solo. Com o intuito de elevar a eficiência energética, o presente trabalho teve como objetivo estimular a produção de metano em reatores anaeróbios em batelada de lodo granular adaptado, alimentados com vinhaça de usina sucroalcooleira, por meio da adição de metais traço. Foram avaliadas as suplementações da vinhaça com Co, Zn, Mo, Ni, Mn e W. Na Fase 1 foram realizados 4 ensaios, os reatores foram analisados individualmente nas concentrações 200 μg.L-1, 350 μg.L-1, 500 μg.L-1 e 800 μg.L-1. Na Fase 2 verificou-se o comportamento dos metais em conjunto, à concentração de 350 μg.L-1 de cada micronutriente (Co, Ni, Zn, Mo, Cu e Mn). Os dados de produção acumulada de CH4 foram ajustados pelo modelo modificado de Gompertz, e foram obtidas as constantes cinéticas. Na Fase 1, verificou-se que a concentração de 200 μg.L-1 de Co foi a mais adequada aos experimentos e apresentou a maior velocidade máxima de produção de CH4, 121,30 mL.d-1 (aumento de 17% na taxa de produção de metano). Nesta mesma Fase, o W apresentou indícios de inibição à concentração de 800 μg.L-1, e os demais metais exibiram os melhores resultados nesta mesma concentração, a velocidade de produção (Rm) aumentou para o Mn (26%), Ni (25%), Cu (21%) e Mo (19%), e os rendimentos mais expressivos foram para Mo (0,267 mL CH4.mg-1 DQOrem), Zn (0,240 mL CH4.mg-1 DQOrem) e Ni (0,232 mL CH4.mg-1 DQOrem). A Fase 2 não apresentou resultados satisfatórios, as verificações não indicaram variação relevante entre os reatores do ensaio e controle. / Anaerobic processing of vinasse is presented as an alternative to energy recovery (biogas), and reuse of its nutritional characteristics through the provision on the ground. In order to increase energy efficiency, this study aimed to stimulate methane production in adapted anaerobic batch reactors with granular sludge fed with vinasse from sugarcane biorefineries, through the addition of trace metals. The supplementation vinasse were evaluated with Co, Zn, Mo, Ni, Mn and W. In phase 1 four essays were realized, and micronutrient were analyzed individually in concentrations of 200 μg.L-1, 350 μg.L-1, 500 μg.L-1 and 800 μ.L-1. In phase 2 it was observed the behavior of metal together, with micronutrients concentration of 350 μg.L-1 (Co, Ni, Zn, Mo, Cu e Mn). The data of methanes production were adjusted by Gompertz modified model and kinetics constants were obtained. In phase 1 it was verified that the concentration of 200 μg.L-1 of Co was optimal for the experiments and showed the highest maximum production velocity of CH4, 121,30 mL.d-1 (increase of 17%). In this phase W showed evidence of inhibition at a concentration of 800 μg.L-1, and other metals showed the best results in the same concentration. The velocity of production (Rm) increased to Mn (26%), Ni (25%), Cu (21%) e Mo (19%), and the most significant yields were to Mo (0,267 mL CH4.mg-1 DQOrem), Zn (0,240 mL CH4.mg-1 DQOrem) and Ni (0,232 mL CH4.mg-1 DQOrem). Phase 2 did not show satisfactory results.

Primeiramente, esse trabalho pretende esclarecer a importância de pesquisas em modelagem, simulação e controle nos processos de tratamento de efluentes e apontar o atraso do Brasil nesta área de pesquisa comparado ao avanço das iniciativas internacionais. O trabalho apresenta o problema específico da modelagem dos processos anaeróbios e propõe uma nova ferramenta de simulação de regime permanente para esses sistemas, desde digestores de lodo a reatores UASB. O simulador se baseia no ADM1 (Anaerobic Digestion Model No 1), modelo proposto pela IWA em 2002, e está implementado em C++. A intenção é disponibilizar livremente um software de simulação com o diferencial de uma metodologia e interface gráfica amigável, capaz de trazer para o dia-a-dia do profissional da área toda a sofisticação de uma modelagem mais completa, tanto do ponto de vista microbiológico como físico-químico. A metodologia proposta se mostrou muito eficiente para a obtenção da condição de regime permanente, fazendo com que a caracterização do afluente se tornasse a etapa limitante do processo de simulação. O método desenvolvido é tão eficaz que permite que sejam realizadas simulações com afluentes e reatores hipotéticos, tornando possível estudos desvinculados da necessidade de análises laboratoriais complexas ou fora do comum. / First, this work intends to show the importance of research in modeling, simulation and control of wastewater treatment processes, and to point the delay of our country (Brazil) in this subject, compared to the advance of the international initiatives. This work presents the specific problem of modeling the anaerobic digestion and proposes a new tool to simulate the steady state condition in anaerobic reactors. The simulator is based on the ADM1 (Anaerobic Digestion Model No 1), developed by IWA in 2002, and is implemented in C++. The intention is to give free access to a new simulation software with the advantages of better methodology and friendly graphical interface. This tool should be able to bring to the professionals all the sophistication of a more complete modelling in the microbiological and physical-chemical point of view. The developed methodology revealed itself to be very efficient for the attainment of the steady state condition. Consequently, it makes the characterization of the influent the critic stage of the simulation process. The developed method is so efficient that allows simulation studies to be carried out using hypothetical influents and reactors. Thus, it brings independence for simulation studies with no need of complex or unusual laboratorial analyses.

Este trabalho comparou oito lagoas de estabilização da região Noroeste do Estado de São Paulo, que tratam esgotos predominantemente sanitários de Coroados, Lourdes, Planalto, Zacarias, Alto Alegre, Pongaí, Irapuã e Adolfo, cidades pequenas, com no máximo 5500 habitantes (1700 ligações), onde os quatro primeiros sistemas são compostos apenas por lagoas facultativas primárias e os quatro últimos por lagoas anaeróbias e lagoas facultativas secundárias. Vinte e cinco variáveis físicas, químicas e biológicas foram analisadas em amostras compostas coletadas entre 24/05/2000 e 03/10/2000. A análise da batimetria efetuada fornece indicações de prazos para a remoção do lodo do fundo das lagoas. As taxas de acúmulo de lodo médias obtidas para as lagoas anaeróbias e facultativas primárias foram de 0,07 e 0,14 m3/hab.ano, respectivamente. O pH do efluente das lagoas anaeróbias e das facultativas foi em média 6,6 e 7,4. Nas lagoas anaeróbias observou-se alta remoção de sólidos suspensos e de Demanda Bioquímica de Oxigênio (DBO) com eficiência geral média de 64% e 61% respectivamente. Os sistemas não atenderam plenamente à legislação no tocante a eficiência de remoção de DBO de 80%, porém o valor médio encontrado para os oito sistemas foi de 78%, bastante próximo do exigido. Sugere-se para a região, para eficiência de remoção de DBO de 80%, lagoas anaeróbias com tempo de detenção de 5 dias e para as lagoas facultativas primárias e secundárias tempos de detenção de 25 e 15 dias respectivamente, e taxas de aplicação superficial de 140 e 130 kg DBO/ha.dia, respectivamente. Não foi atingido o limite máximo de 1000 coliformes fecais por 100 ml, obtendo-se média geral de remoção de 97,40% inferindo-se que há necessidade de um processo de tratamento complementar para a remoção de microrganismos. Não observou-se correlação entre eficiência do sistema e relação comprimento/largura das lagoas. Constatou-se maus odores mesmo na ausência de concentrações detectáveis de sulfeto. A remoção média geral de amônio (NH4+), nitrogênio total, fosfato total dissolvido e fósforo total foi de 31%, 12%, 24% e 27% respectivamente nos sistemas estudados. / The present work compared the performance of eight stabilization ponds in the Northwest region of São Paulo state, that treat predominantly the domestic sewage from eight small cities with a maximum of 5000 inhabitants (1700 links): Coroados, Lourdes, Planalto, Zacarias, Alto Alegre, Pongaí, Trapuã and Adolfo. The first four systems are made of four primary facultative ponds and the last four by anaerobic ponds and secondary facultative ponds. A total of twenty-five chemical, physical and biological variables were analyzed in integrated samples collected between 24/05/2000 and 03/10/2000. The bathymetric analysis performed has indicated deadlines for sludge removal from the stabilization pond bottom. Mean sludge accumulation rates o btained for anaerobic and primary facultative ponds were 0.07 and 0.14 m3/inhabt.year, respectively. Effluents from anaerobic and facultative ponds had a mean pH of 6.6 and 7.4. In anaerobic ponds a righ rate of suspended solids removal was found and the Biochemical Oxygen Demand (BOD) had an overall general efficiency of 64% and 61%, respectively. The systems did not completely attend the present legislation in respect to a BOD removal of 80%, as required, however the mean value for the eight systems monitored was 78%, very close to the established limit. It is therefore suggested that for this region, in order to attain the removal efficiency of 80% anaerobic ponds should have a residence time of 5 days and the primary and secondary facultative ones should have residence times of 25 and 15 days respectively, coupled to loading rates of 140 and 170 Kg BOD/ha.day respectively. Also, the maximum limit of 1000 fecal coliforms per 100 ml was not reached, and in general there was a mean removal efficiency of 97.40%, indicating that an additional treatment process needs to be implemented for a successful removal of coliforms. No correlation was found between the removal efficiency and morphometry (length/weight) pond characteristics. Bad smell was present even in the absence of detectable amounts of sulfide. The mean efficiency for the removal of ammonium (NH4+), total nitrogen, total dissolved phosphorus and total phosphorus were 31%, 12%, 24%, and 27% respectively, among the systems studied.

Made available in DSpace on 2015-09-25T12:23:37Z (GMT). No. of bitstreams: 1 Silvia Peres de Castro.pdf: 565210 bytes, checksum: bc1094dba26205895b29d51dc104b086 (MD5) Previous issue date: 2009-08-21 / The increasing global demand for energy and the diversity of manufactured products generates diverse residues that are frequently difficult to treat or degrade. The utilization of petroleum and its derivatives cause environmental damage via oil spillages and effluents generated by diverse processes such as car washes, petrol stations, public transport companies and even industrial kitchens. In this study a biological treatment was used as an alternative to treat these pollutants, which included two basic treatments to remove organic material: an aerobic process namely activated sludge and an anaerobic process, comprising a UASB reactor. The objective of this work was to treat by biological processes, a synthetic effluent derived from petroleum which characterized physico-chemically, as having oily characteristics, to evaluate comparatively the efficiency of organic matter removal via two different processes of biodegradation. The results obtained were submitted to statistical analysis by Box Plots and ANOVA at a significance level of 5%. The experimental work with bench scale activated sludge and UASB reactors was performed at The Experimental Station for the Biological Treatment of Sewage EXTRABES in Campina Grande - PB, using effluents synthesized in the laboratory to feed the reactors at elevated loads of organic matter containing lubricating oil and surfactants. The adopted treatments had significant organic carbon removal efficiencies; with values of 23.7 to 32% for aerobic treatment and 42 to 51% with anaerobic treatment thus demonstrating that UASB treatment was the more efficient process and could be adopted for the treatment of oily and surfactant-containing effluents. / A crescente demanda de energia necessária no mundo e a diversidade de produtos obtidos geram diversos resíduos difíceis de serem tratados. A utilização do petróleo e seus derivados causam danos ambientais, estes vêm desde os derramamentos de petróleo e seus componentes até mesmo de efluentes gerados nos mais diversos processos, como em lava-jatos, postos de combustíveis, empresas de transportes públicos e até mesmo em cozinhas industriais. Neste estudo utilizar-se-á tratamento biológico, como uma alternativa para o tratamento desses poluentes, dentre estes tratamentos tem se dois processos básicos para a remoção de material orgânico que foi estudado: os sistemas de lodos ativados e os reatores UASB. O objetivo desse trabalho foi tratar através de processos biológicos, efluentes sintéticos derivados do petróleo, bem como realizar a caracterização físico-química deste efluente oleoso, e determinar comparativamente a eficiência de remoção da matéria orgânica através de processos de biodegradação biológica. Os resultados obtidos foram submetidos a métodos estatísticos: estatística descritiva de distribuição (Box Plot) e análise de variância (ANOVA) fator único, com nível de significância de 5%. O trabalho experimental foi realizado na Estação Experimental de Tratamentos Biológicos de Esgotos Sanitários EXTRABES, localizado no bairro do Tambor na cidade de Campina Grande PB. Para a realização da pesquisa foram construídos, instalados e monitorados reatores de lodo ativado e UASB em escala de bancada. Os reatores foram alimentados com efluentes sintetizados no laboratório. Com esse procedimento buscou-se tratar biologicamente efluentes com elevada carga orgânica, contendo óleo lubrificante e substâncias surfactantes. Nos tratamentos adotados foi conseguido uma eficiência de remoção significativa, o tratamento aeróbio teve remoções de 23,7 a 32,1%, no tratamento anaeróbio a remoção da matéria orgânica foi de 51 e 42%, o que mostra que o tratamento anaeróbio utilizando o reator UASB teve uma melhor remoção da matéria orgânica, podendo esses tratamentos serem adotados para o tratamento de efluentes oleosos e surfactantes.

Este trabalho comparou oito lagoas de estabilização da região Noroeste do Estado de São Paulo, que tratam esgotos predominantemente sanitários de Coroados, Lourdes, Planalto, Zacarias, Alto Alegre, Pongaí, Irapuã e Adolfo, cidades pequenas, com no máximo 5500 habitantes (1700 ligações), onde os quatro primeiros sistemas são compostos apenas por lagoas facultativas primárias e os quatro últimos por lagoas anaeróbias e lagoas facultativas secundárias. Vinte e cinco variáveis físicas, químicas e biológicas foram analisadas em amostras compostas coletadas entre 24/05/2000 e 03/10/2000. A análise da batimetria efetuada fornece indicações de prazos para a remoção do lodo do fundo das lagoas. As taxas de acúmulo de lodo médias obtidas para as lagoas anaeróbias e facultativas primárias foram de 0,07 e 0,14 m3/hab.ano, respectivamente. O pH do efluente das lagoas anaeróbias e das facultativas foi em média 6,6 e 7,4. Nas lagoas anaeróbias observou-se alta remoção de sólidos suspensos e de Demanda Bioquímica de Oxigênio (DBO) com eficiência geral média de 64% e 61% respectivamente. Os sistemas não atenderam plenamente à legislação no tocante a eficiência de remoção de DBO de 80%, porém o valor médio encontrado para os oito sistemas foi de 78%, bastante próximo do exigido. Sugere-se para a região, para eficiência de remoção de DBO de 80%, lagoas anaeróbias com tempo de detenção de 5 dias e para as lagoas facultativas primárias e secundárias tempos de detenção de 25 e 15 dias respectivamente, e taxas de aplicação superficial de 140 e 130 kg DBO/ha.dia, respectivamente. Não foi atingido o limite máximo de 1000 coliformes fecais por 100 ml, obtendo-se média geral de remoção de 97,40% inferindo-se que há necessidade de um processo de tratamento complementar para a remoção de microrganismos. Não observou-se correlação entre eficiência do sistema e relação comprimento/largura das lagoas. Constatou-se maus odores mesmo na ausência de concentrações detectáveis de sulfeto. A remoção média geral de amônio (NH4+), nitrogênio total, fosfato total dissolvido e fósforo total foi de 31%, 12%, 24% e 27% respectivamente nos sistemas estudados. / The present work compared the performance of eight stabilization ponds in the Northwest region of São Paulo state, that treat predominantly the domestic sewage from eight small cities with a maximum of 5000 inhabitants (1700 links): Coroados, Lourdes, Planalto, Zacarias, Alto Alegre, Pongaí, Trapuã and Adolfo. The first four systems are made of four primary facultative ponds and the last four by anaerobic ponds and secondary facultative ponds. A total of twenty-five chemical, physical and biological variables were analyzed in integrated samples collected between 24/05/2000 and 03/10/2000. The bathymetric analysis performed has indicated deadlines for sludge removal from the stabilization pond bottom. Mean sludge accumulation rates o btained for anaerobic and primary facultative ponds were 0.07 and 0.14 m3/inhabt.year, respectively. Effluents from anaerobic and facultative ponds had a mean pH of 6.6 and 7.4. In anaerobic ponds a righ rate of suspended solids removal was found and the Biochemical Oxygen Demand (BOD) had an overall general efficiency of 64% and 61%, respectively. The systems did not completely attend the present legislation in respect to a BOD removal of 80%, as required, however the mean value for the eight systems monitored was 78%, very close to the established limit. It is therefore suggested that for this region, in order to attain the removal efficiency of 80% anaerobic ponds should have a residence time of 5 days and the primary and secondary facultative ones should have residence times of 25 and 15 days respectively, coupled to loading rates of 140 and 170 Kg BOD/ha.day respectively. Also, the maximum limit of 1000 fecal coliforms per 100 ml was not reached, and in general there was a mean removal efficiency of 97.40%, indicating that an additional treatment process needs to be implemented for a successful removal of coliforms. No correlation was found between the removal efficiency and morphometry (length/weight) pond characteristics. Bad smell was present even in the absence of detectable amounts of sulfide. The mean efficiency for the removal of ammonium (NH4+), total nitrogen, total dissolved phosphorus and total phosphorus were 31%, 12%, 24%, and 27% respectively, among the systems studied.

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.

Combined treatment technologies for the removal of waste carbon, nitrogen, and/or sulfur under anoxic/anaerobic conditions have recently received considerable attention. It has been reported that nitrate and/or reduced N-oxides, such as nitrite (NO2-), nitric oxide (NO), and nitrous oxide (N2O), which are products of denitrification, suppress methanogenesis. Research was conducted to investigate the effect of N-oxides and sulfide on mixed, mesophilic (35oC) methanogenic cultures, along with the effect of the type of electron donor on the kinetics and pathway of nitrate reduction. Among all N-oxides tested, NO exerted the most and nitrate exerted the least inhibitory effect on the fermentative/methanogenic consortia. Long-term exposure of a methanogenic culture to nitrate resulted in an increase of N-oxide reduction and a decrease of methane production rates. Sulfide addition to sulfide-free enriched cultures resulted in inhibition of NO2-, NO, and N2O reduction causing accumulation of these intermediates, which in turn inhibited methanogenesis and fermentation. In nitrate-amended, sulfide-acclimated cultures, nitrate reduction occurred via dissimilatory nitrate reduction to ammonia (DNRA); thus, accumulation of N-oxides was avoided and inhibition of methanogenesis was prevented. The nitrate reduction rates in cultures fed with different electron donors followed the descending order: H2/CO2 > acetate > glucose > dextrin/peptone > propionate. Denitrification was observed in the propionate-, acetate-, and H2/CO2-fed cultures regardless of the COD/N value. Both denitrification and DNRA were observed in the dextrin/peptone- and glucose-fed cultures and the predominance of either of the two pathways was a function of the COD/N value. Nitrate reduction processes were incorporated into the IWA Anaerobic Digestion Model No. 1 (ADM1) in order to account for the effect of nitrate reduction processes on fermentation and methanogenesis. The extended ADM1 described the experimental results very well. Model simulations showed that process interactions during nitrate reduction within an overall methanogenic system cannot be explained based on only stoichiometry and kinetics, especially for batch systems and/or continuous-flow systems with periodic, shock nitrate loads. The results of this research are useful in predicting the fate of carbon-, nitrogen-, and sulfur-bearing waste material, as well as in understanding microbial process interactions, in both natural and engineered anoxic/anaerobic systems.

Swine manure creates much public resentment in Quebec due to nutrient overloading, potential water pollution and odour. Anaerobic digestion is one of the solutions that allows to lessen the odour problem. Anaerobic bacteria in manure produce methane. The latter can be burnt to produce heat and electricity on farms. Moreover, there is a potential for receiving carbon emission reduction credits for the capturing of methane. / Investment analysis was performed to assess the economic feasibility of a potential anaerobic digestion system on a grower-to-finisher hog operation. The study was conducted for a case farm, which had plans to expand from 2000 to 4800 pigs. Greenhouse gas emission reduction credits were incorporated into one of the scenarios. A sensitivity analysis revealed the most important variables which affect the economic feasibility of anaerobic digestion.

Thesis (MScFoodSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Waste generated by the distillery industry is a major ecological concern and disposal thereof without a suitable treatment can have damaging effects on the environment. The characteristics of this type of wastewater are highly variable and dependent on the raw material used and production process followed. Grain distillery wastewater (GDWW) is also rich in fats, oils and grease (FOG). Successful treatments of distillery wastewater and GDWW have been reported using an upflow anaerobic sludge blanket (UASB) reactor technology. The aim of this study was to investigate the ability of lab-scale UASB reactor to treat FOG-reduced GDWW and the subsequent enhancement thereof following an unique feeding strategy approach. Firstly, a coagulation/flocculation-centrifugation step was developed to obtain FOG-reduced GDWW. Secondly, the efficiency of a lab-scale UASB reactor was investigated treating FOG-reduced GDWW at pre-determined operational parameters as well as the verification of biomass acclimatisation. Lastly, the effect of a unique feeding strategy of FOG-reduced GDWW to lab-scale UASB reactor granules was investigated in terms of COD, FOG-reduction and biomass acclimatisation. It was found that a coagulation/flocculation-centrifugation treatment removed sufficient amounts of FOG and TSS from GDWW. Different commercially available coagulation/flocculation products were evaluated whilst used in combination with a centrifugation step for improved sedimentation and separation. The FOG removal remained between 90 and 97% for the ferric chloride (FeCl3) and Ferrifloc 1820 treatments, respectively, whereas the TSS removal ranged between 56 and 93%, respectively. The use of a high molecular weight polymer (Ultrafloc 5000) and an aluminium chlorohydrate (Ultrafloc 3800) proved to be less effective in terms of FOG removal efficiency, ranging from 72 to 86%. It was decided to pre-treat GDWW with FeCl3 in combination with centrifugation to obtain FOG-reduced GDWW for subsequent UASB reactor treatment investigations. The FOG-reduced GDWW was fed into a laboratory-scale UASB reactor (2 L) over a period of 331 days. During the operational period different feeding parameters were attained to establish the ability of the UASB reactor to efficiently treat FOG-reduced GDWW. The COD removal increased from 60 to 85% at an organic loading rate (OLR) of ca. 5.5 kgCOD.m-3.d-1 (pH = 7.5) whilst FOG removal remained between 45 and 70%. COD removal increased to 90% with the attainment of an OLR of ca.10 kgCOD.m-3.d-1 (pH = 7.5) whereas FOG removal remained in the region of 55 and 65%. COD and FOG removal remained above 85% and 50%, respectively, when substrate pH was decreased to 6.50 (OLR ca. 10 kgCOD.m-3.d-1). A granule activity test was performed on seed and FOG-reduced GDWW fed granules to determine biomass acclimatisation. FOG-reduced GDWW fed granules showed higher activity in terms of methane production rate and cumulative methane production suggesting biomass acclimatisation. The FOG-reduced GDWW was fed to a laboratory-scale UASB reactor following a unique feeding approach. The feeding approach consisted of several feeding and starvation cycles. Improved average biogas production was observed during the feeding (0.26 to 11.3 L.d-1) and starvation (1.8 to 4.2 L.d-1) cycles as higher loading rates were obtained during each feeding cycle. After the completion of the strategic feeding the UASB reactor was continuously fed at an organic loading rate of ca. 5 kgCOD.m-3.d-1. The COD reduction efficiency improved from 70 to 80%, however, FOG removal remained in the region of 60%. Granule activity tests done on days 0, 215 and 279 showed improved UASB granule activity to FOG-reduced GDWW with operation time in terms of methane production rate and cumulative methane production. This study has proven that a coagulation/flocculation-centrifugation treatment of GDWW can remove sufficient amounts of FOG and TSS before the commencement of a UASB treatment, however, such a technique would require more refinement. It was also found that a UASB reactor can successfully treat FOG-reduced GDWW, however, it must be advised that close monitoring of the UASB reactor is required in order to maintain efficient COD reduction. A strategic feeding approach proved to be successful, but further improvement of the UASB efficiency to treat FOG-reduced GDWW in terms of stable COD and FOG reduction, stable effluent pH, improved biogas production and biomass activity must still be explored. / AFRIKAANSE OPSOMMING: Afloop water wat gegenereer word deur die distillerings-industrie veroorsaak ‘n ekologiese kommer en wegdoening daarvan sonder geskikte behandeling, kan ernstige gevolge op die omgewing hê. Die eienskappe van hierdie tipe afvalwater kan varieer en is afhanklik van die rou materiale gebruik en die produksie proses wat gevolg is. Graan distillery afloop water (GDAW) deel dieselfde eienskappe met die van distillery afloop water, alhoewel dit ook hoog is in vette, olies en ghries (VOG). Suksesvolle behandeling van distillery afloop water en GDAW met n opvloei-anaërobiese slykkombers (OAS) reaktor is deur verskeie navorsers gerapporteer. Die doel van hierdie studie was om die uitvoerbaarheid van laboratorium skaal OAS reaktor, wat VOG-verminderde GDAW behandel te ondersoek, asook die daaropvolgende verbetering deur n unieke voer strategie te volg. Eerstens, was ‘n koagulasie/flokkulasie-sentrifigasie tegniek ontwikkel om VOG-verminderde GDAW te kry. Tweendens, die effektiwiteit van ‘n lab-skaal OAS reaktor ondersoek, wat gevoer was met VOG-verminderde GDAW, by voorafbepaalde parameters. Laastens, die effek van ‘n unieke voer strategie van VOG-verminderde GDAW op lab-skaal OAS reaktor granules. Dit was vasgestel dat ‘n koagulasie/flokkulasie-sentrifigasie voor behandeling voldoende hoeveelhede VOG en TSS verwyder van GDAW. Verskillende kommersieel beskikbare koagulasie/flokkulasie produkte was in kombinasie met ‘n sentrifugasie stap geëvalueer om sedimentasie en skeiding te verbeter. Dit was nie ‘n plan om die stap te perfek nie, maar dat dit eerder sou dien as ‘n voorbehandeling stap vir opeenvolgende ondersoeke. Die VOG verwydering het tussen 90 en 97% gevariëer vir ferri chloride (FeCl3) en Ferrifloc 1820 (Chlorchem) en TSS verwydering het tussen 56 en 93% gewissel. Die gebruik van ‘n hoë molekulêre gewig polimeer (Ultrafloc 5000) en ‘n aluminium chlorohidraat (Ultrafloc 3800) was minder effektief met n VOG verwydering wat tussen 72 en 86% gewissel het. Die VOG-verminderde GDAW was in ‘n laboratorium-skaal OAS reaktor oor ‘n tydperk van 331 dae behandel. Verskillende voer doelwitte was geëvaluaeer om te bepaal of ‘n OAS reaktor GDAW suksesvol kan behandel. CSB afbraak het van 60 to 85% gestyg teen ‘n organiese lading van 5.5 kgCOD.m-3.d-1 (pH 7.50), met VOG verwydering wat tussen 45 en 70% gewissel het. Die CSB afbraak het na die bereiking van 10 kgCOD.m-3.d-1 (pH 7.50) gestyg na 90% met VOG afbraak tussen 55 en 60% gewissel het. Die CSB en VOG verwydering het bo 85% en 50% onderskeidelik gebly, met die verlaging van substraat pH na 6.50 (CSB ca. 10 kgCOD.m-3.d-1). ‘n Aktiwiteits toets is uitgevoer met saad granules en VOG-verminderde GDAW gevoerde granules. Granules (VOG-verminderde GDAW gevoer) het ‘n hoer aktiwiteit getoon teenoor saad granules in terme van metaan produksie tempo en kumulatiewe metaan produksie. Die VOG-verminderde GDAW was gevoer in ‘n OAS reaktor deur gebruik te maak van ‘n strategiese voertegniek. Die strategie het uit verskeie voer en hongersnood fases bestaan. Verbeterde biogas produksie was tydens voer (0.26 tot 11.3 L.d-1) en hongersnood (1.8 tot 4.2 L.d-1) -fases opgelet soos ‘n hoër lading bereik was. Na die voltooing van die strategiese voer fase was die OAS reaktor op ‘n deurlopende basis teen ‘n lading van 5 kgCOD.m-3.d-1 gevoer. Die CSB verwydering het van 70 na 80% verhoog terwyl VOG afbraak in die omgewing van 60% gewissel het. Biomassa aktiwiteits toetse was uitgevoer is op dag 0, 215 en 279 het verhoogde aktiwiteit vertoon, met ‘n strategiese fase en deurlopende fase teenoor die aanvanklike (ongeaklamatiseerde) granules. Hierdie studie het bewys dat ‘n flokkulasie/koagulasie-sentrifugasie behandeling van GDAW kan dien as ‘n voorbehandelings stap vir opeenvolgende OAS reaktor studies. Dit was gevind dat ‘n OAS reaktor die VOG-verminderde GDAW kan behandel, maar dit word aanbeveel dat die OAS reaktor so sorgvuldig as moontlik gemonitor word om effektiewe CSB verwydering te handhaaf. Ten slotte, ‘n strategiese voer strategie was suksesvol, maar verdere verbetering van die OAS reaktor ten opsigte van die behandeling van VOG-verminderde GDAW moet verder ondersoek word.