A presente pesquisa avaliou diferentes razões de recirculação do meio líquido com a finalidade de identificar a melhor condição de mistura para uma produção elevada e contínua de hidrogênio em um reator anaeróbio de leito fixo com fluxo ascendente alimentado com um meio contendo sacarose como fonte de carbono e uréia como fonte de nitrogênio. Foi utilizado polietileno de baixa densidade como meio suporte para imobilização da biomassa. O experimento foi iniciado com ensaios hidrodinâmicos (pulso, utilizando dextran blue como traçador) que determinaram as seguintes razões de recirculação em relação à vazão de alimentação utilizadas: R = 0,25, 0,5, 1,0 e 2,0. O experimento foi realizado em duas etapas, nas quais foram operados dois reatores idênticos simultaneamente, testando-se duas razões de recirculação diferentes. A DQO da água residuária foi de 2000 mg/L. O tempo de detenção hidráulica teórico foi de 2 horas e a temperatura foi mantida em 25 graus Celsius. A remoção de sacarose apresentou valores médios de 67%, 79%, 71% e 70% para R = 0,25, 0,5, 1,0 e 2,0, respectivamente. Os valores médios de rendimento de hidrogênio foram 1,14 mol \'H IND.2\'/mol sac, 1,43 mol \'H IND.2\'/mol sac, 1,34 mol \'H IND.2\'/mol sac e 0,86 mol \'H IND.2\'/.mol sac e de produção volumétrica de hidrogênio foram 74,34 mL \'H IND.2\'/(h.L), 124,78 mL \'H IND.2\'/(h.L), 96,57 mL \'H IND.2\'/(h.L) e 73,49 mL \'H IND.2\'/(h.L) para as vazões de recirculação de 0,25, 0,5, 1,0 e 2,0, respectivamente. O biogás produzido foi composto de \'H IND.2\', e \'CO IND.2\', com valores percentuais médios para \'H IND.2\', de 50%, 56%, 56% e 46% para R = 0,25, 0,5, 1,0 e 2,0, respectivamente. Não houve presença de metano em nenhuma fase de operação. Os principais produtos intermediários produzidos durante a produção de \'H IND.2\', foram ácido acético, ácido butírico e etanol, de forma similar para todas as fases de recirculação. Analisando todos os parâmetros de operação, foi possível notar que a melhor vazão de recirculação obtida foi de R = 0,5. Ajustando os dados obtidos a uma função polinomial, porém, chegou-se a um ponto de ótimo em R = 0,6. Durante os experimentos observou-se uma queda na produção do biogás, provavelmente por atuação de microrganismos consumidores deste. / The present research evaluated different recirculation rates of the liquid medium for the purpose of identify the best mixture condition for a high and continuous hydrogen production in an anaerobic upflow fixed-bed reactor fed with a medium containing sucrose as carbon source and urea as nitrogen source. Low density polyethylene was used as medium for biomass immobilization. The experiment began with hydrodynamic tests (pulse, using dextran blue as tracer) which led to the following recirculation rates related with the feed flow rate used in this work: R = 0,25, 0,5, 1,0 and 2,0. The experiment was conducted in two stages, where two identical reactors were operated simultaneously, by testing two different recirculation rates. COD from wastewater was 2000 mg/L. The theoretical hydraulic retention time was 2 hours and the temperature was maintained at 25 Celsius degrees. The average values of sucrose consumption were 67%, 79%, 71% and 70% for R = 0,25, 0,5, 1,0 and 2,0, respectively. The average values of hydrogen yield were 1,14 mol \'H IND.2\'/mol sac, 1,43 mol \'H IND.2\'/mol sac, 1,34 mol \'H IND.2\'/mol sac and 0,86 mol \'H IND.2\'/mol sac and of hydrogen production rate were 74.34 mL \'H IND.2\'/(h.L), 124.78 mL \'H IND.2\'/(h.L), 96.57 mL \'H IND.2\'/(h.L) and 73.49 mL \'H IND.2\'/(h.L) for recirculation rates of 0.25, 0.5, 1.0 and 2.0, respectively. The biogas produced was composed by \'H IND.2\', and \'CO IND.2\', with average values for \'H IND.2\', of 50%, 56%, 56% and 46% for R = 0,25, 0,5, 1,0 and 2,0, respectively. Methane was not detected. The main intermediate products produced during the hydrogen production were acetic acid, butyric acid and ethanol, similar in all stages of recirculation. Analyzing all operating parameters, it was identified that the better recirculation rate obtained during the experiments was R = 0.5. Adjusting all data obtained with a polynomial function, it was found an optimal recirculation rate of R = 0.6. During the experiments there was a drop in biogas production, probably by the activity of microrganisms consumers of this biogas.

Made available in DSpace on 2017-07-21T18:53:15Z (GMT). No. of bitstreams: 1 Silvia Pukasiewicz.pdf: 807504 bytes, checksum: 46c5fee11c6e26495932d6b13679bc20 (MD5) Previous issue date: 2010-06-18 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / The process of anaerobic digestion is presented as an alternative for treatment of effluents from various industrial activities. In this case there is the conversion of organic matter to more stable compounds such as methane, which can be used to replace fossil fuels. This study evaluated the treatment of effluent generated by a processing company for animal feed flavors, which uses as raw material waste generated in the slaughter and processing of pigs, chickens and turkeys. It was used a biological upflow anaerobic filter, constructed of polyvinyl chloride with a volume of 980 mL and support material for biomass consisting of rings of polypropylene, with the goal of removing organic matter and produce biogas. The influent had average values with the following characteristics: 899.79 mg L-1 of COD, pH of 8.12, 377.31 mg L-1 of total nitrogen, 206.09 mg L-1 of ammoniacal nitrogen, 2.90 mg L-1 of oils and greases, 768.67 mg CaCO3 L-1 of alkalinity, 521.26 mg L-1 CH3COOH of volatile acidity and 15.11 mg L-1 content of phosphorous. The system was operated continuously at room temperature, organic loading of 0.077, 0.102, 0.154, 0.356, 0.536, 0.854, 1.083 kg DQO m-3 d-1, and HRT 240, 168, 120, 72, 48, 24 and 21 hours. The effluent had COD values between 14.43 and 849.43 mg L-1, pH between 6.32 and 8.34, total nitrogen between 95.23 and 742.14 mg L-1, ammoniacal nitrogen between 127,78 and 230.29 mg L-1, alkalinity between 268.83 and 2401.5 mg CaCO3 L-1 and volatile acidity between 27.66 and 415.30 mg L-1 CH3COOH and phosphorus content between 0 and 29, 26 mg L-1. The best results of COD removal were obtained with HRT of 24 hours, averaging 83% removal and, consequently, larger generation of biogas, 48.39 kg of methane per day. Concludes that, within the conditions employed, the anaerobic digestion process was efficient in removing COD. If the company uses the methane produced in power generation, can enter in the market of carbon credits and get an extra income. / O processo de digestão anaeróbia apresenta-se como uma alternativa para tratamento de efluentes de várias atividades industriais. Nesse processo há conversão da matéria orgânica a compostos mais estáveis como o gás metano, que pode ser utilizado em substituição aos combustíveis fósseis. Neste trabalho foi avaliado o tratamento anaeróbio dos efluentes gerados por uma empresa processadora de palatabilizantes para ração animal, que utiliza como matéria prima os subprodutos gerados no abate e processamento de suínos, frangos e perus. Foi utilizado um filtro biológico anaeróbio de fluxo ascendente, construído de policloreto de vinila com volume útil de 980 mL e material suporte para a biomassa constituído por anéis de polipropileno, com o objetivo de remover a matéria orgânica e produzir biogás. O substrato possuía valores médios com as seguintes características: DQO de 899,79 mg L-1, pH de 8,12, nitrogênio total de 377,31 mg L-1, nitrogênio amoniacal de 206,09 mg L-1, teor de óleos e graxas de 2,90 mg L-1, alcalinidade de 768,67 mg CaCO3 L-1, acidez volátil de 521,26 mg CH3COOH L-1 e teor de fósforo de 15,11 mg L-1. O filtro foi operado por 196 dias, à temperatura ambiente, com cargas orgânicas de 0,077; 0,102; 0,154; 0,356; 0,536; 0,854; 1,083 kg DQO m-3 d-1, e TRH de 240, 168, 120, 72, 48, 24 e 21 horas. O efluente tratado apresentou valores de DQO entre 14,43 e 849,43 mg L-1, pH entre 6,32 e 8,34, nitrogênio total entre 95,23 e 742,14 mg L-1, nitrogênio amoniacal igual entre 127,78 e 230,29 mg L-1, alcalinidade entre 268,83 e 2401,5 mg CaCO3 L-1 e acidez volátil entre 27,66 e 415,30 mg CH3COOH L- 1 e teor de fósforo entre 0 e 29,26 mg L-1. Os melhores resultados de remoção de DQO foram obtidos com TDH de 24 horas, com média de 83% de remoção e, conseqüentemente, maior geração de biogás, 48,39 kg de metano por dia. Concluise que, dentro das condições empregadas, o processo de digestão anaeróbia foi eficiente na remoção de DQO. Se a empresa utilizar o metano produzido na geração de energia, poderá entrar no mercado de créditos de carbono e obter uma renda extra.

Water scarcity is a global concern that impacts many developing countries, forcing people to depend on unclean water sources for domestic, agricultural, and industrial needs. Wastewater is an alternative water source that contains nutrients needed for crop growth. Wastewater reuse for agriculture can cause public health problems because of human exposure to pathogens. Pathogen monitoring is essential to evaluate the compliance of wastewater with established World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) wastewater reuse guidelines. Indicator organisms are commonly used to detect pathogens in water and wastewater because they are quick and easy to measure, non-pathogenic, and have simple and inexpensive methods of detection. The objective of this research was to develop a modified double agar layer assay method that can be conducted in the field to quantify bacteriophage to assess the quality of wastewater for agricultural reuse. Results from the modified double agar layer assay were used to investigate the potential of somatic coliphage as an indicator organism for assessing the potential presence of enteric viruses in developing world treated wastewater, and to use the criteria of a good indicator organism to compare the potential of two commonly used indicator organisms, somatic coliphage and fecal coliforms, as an indicator of enteric viruses in wastewater. A modified EPA double agar layer method was developed and deployed in a developing world rural community to effectively quantify the concentration of somatic coliphage in a community managed wastewater treatment system composed of a Upflow Anaerobic Sludge Blanket (UASB) reactor followed by two maturation lagoons. The modified method served as a good indicator of enteric viruses in the water. Somatic coliphages were easily detected and quantified in the field setting using a modified double agar layer method. Somatic coliphage was found to be a potential indicator for enteric viruses rather than fecal coliforms because of their similarity in characteristics and resistances to wastewater treatment. The concentration of somatic coliphage was only reduced by 1.05 log units across the two series maturation lagoon system. Previous literature suggested removal would range from 2.1 to 4.6 log units. Influent wastewater (previously treated by an UASB reactor) had a concentration of 4.38 E+06 PFU/ 100 mL (standard deviation = ±3.7E+06, n = 9) and the treated effluent contained 3.90 E+05 PFU/100 mL (standard deviation = ± 4.5E+05, n = 8) of somatic coliphages. Results suggest that somatic coliphage is a good potential indicator for enteric viruses in wastewater but further research needs to be done.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The "classical" propionibacteria are used in a variety of natural dairy fermentations where they produce natural preservatives (propionic and acetic acids and bacteriocins) and large amounts of vitamin B12. The extracellular polysaccharide (ECP) producing ability of these bacteria also make them of special interest to the food and waste water management industries as the ECP has been illustrated to playa role in the initial granule formation in upflow anaerobic bioreactor systems. There is little known on the ECP production by propionibacteria and in this study different environmental conditions that influence ECP production were studied. Nineteen different Propionibacterium strains were examined in terms of ECP production and Propionibacterium strain 278 was identified as the best ECP producer. Further studies were only done on this strain because of its high ECP production and because it was originally isolated from an anaerobic digester. The influence of temperature, pH and sucrose concentration was determined through the measurement of ECP production and medium viscosity. It was found that more ECP was produced at temperatures lower than the optimum for growth with the optimum being between 22° and 25°C. Lower initial pH conditions of the growth medium (below pH 7.0) were found to inhibit ECP production and the influence when the initial pH values were between 7.0 and 8.5, was not significant. A higher carbon: nitrogen ratio, when 8% sucrose was added, was also found to enhance the ECP production. The upflow anaerobic sludge bed (UASB) bioreactor process depends on the upward movement of soluble matter through a blanket of active methanogenic granular sludge. The long start-up times as a result of the slow granulation process, as well as the need for a speedy replacement of granules once they have been washed out of the system, are limitations that restrict the general application of this excellent waste water treatment technology. Full exploitation of this biomass immobilisation technique can thus not be realised until the granule formation conditions are defined and optimised. The precise nature of the mechanisms involved in the formation of granules and the reason for their stability, is still not fully understood. It was hypothised by Britz et al. in 1999 that, through the implementation of environmental 'stress' conditions, a shift in the population dynamics of the anaerobic community can be obtained. This results in a concurrent increase in ECP formation that appears to enhance aggregate formation. In the second study it was found that, when 'stress' conditions were applied to already formed granules, the Gram-positive lactate-utilising acidogenic population gained an advantage and more propionic acid producing bacteria were present. The propionic and acetic acid concentrations were also found to increase, and concurrently, a decrease in the growth medium pH occurred. This confirms part of the granulation hypothesis that, when granules are 'stressed', the acidogenic population dynamics change and the lactate-utilising population responds to the gradual decrease in pH and the more acid-tolerant propionic acid producing bacteria gain a competitive advantage resulting in the increase in the propionic acid concentration. When propionibacteria were added to raw sludge during the granule production process, the granules were found to be more active than when nopropionibacteria had been added. This was probably due to the ECP formation by the propionibacteria that enhances the aggregation of the granules. Enhanced granulation was thus found in the batch systems with the fatty acids formed in correlation with the model for granulation. A good correlation was evident between the hypothesis and the experimental data and the hypothesis was partially verified in this study. / AFRIKAANSE OPSOMMING: Die "klassieke" propionibakterieë word in 'n verskeidenheid van natuurlike suiwel fermantasies gebruik waarin hulle verantwoordelik in vir die produksie van natuurlike voedsel preserveermiddels (propioonsuur, asynsuur en bakteriosiene) en groot hoeveelhede vitamiene B12. Die Ekstra Sellulêre Pollisakkaried (ESP) produserende eienskap van hierdie groep bakterieë maak hulle ook van belang in die voedsel en afvoerwater beheer industrieë, aangesien gevind is dat ESP 'n rol speel in die aanvanklike granule formasie in anaerobiese bioreaktor sisteme. Daar is nog baie min bekend oor die ESP produksie van propionibakterieë en in hierdie studie is verskeie omgewings faktore wat die ESP produksie beïnvloed, bestudeer. Negentien verskillende Propionibakterium stamme was bestudeer in terme van ESP produksie en Propionibakterium stam 278 was geïdentifiseer as die stam wat die meeste ESP produseer. Verdere studies was op hierdie stam gedoen na aanleiding van sy hoë ESP produksie en omdat dit oorspronklik uit 'n anaerobiese verteerder geisoleer is. Die invloed van termperatuur, pH en sukrose konsentrasie was bepaal deur die meting van die ESP produksie en die medium viskositeit. Dit was gevind dat meer ESP geproduseer was by temperature laer as die optimum vir groei, met die optimum temperatuur tussen 22° en 25°C. Dit is ook gevind dat laer aanvangs groei-medium pH (laer as pH 7.0), ESP produksie inhibeer. Die invloed van die aanvangs groei-medium pH tussen 7.0 en 8.5 was egter nie betekenisvol nie. Dit is ook gevind dat 'n hoër koolstof tot stikstof verhouding, verkry deur die byvoeging van 8% sukrose, die ESP produksie verhoog. Die "upflow anaerobic sludge blanket" (UASB) proses vind plaas as gevolg van die opwaarste beweging van opgeloste organiese materiaal deur 'n granule bed van aktiewe metanogeniese granulêre slyk. Die lang 'start-up' tye as gevolg van die stadige granulasie proses, en die nodigheid om 'n vinnige verplasing van granules te hê nadat dit uit die sisteem gewas is, is beperkings wat die algemene toepassing van hierdie fantastiese afvoerwater tegnologie, strem. Volle implementering van hierdie biomassa immobilisereings tegniek kan dus nie plaasvind voordat die granule formasie gedefinieer en geoptimiseer is nie. Die presiese eienskappe van die meganismes betrokke en die formasie van die granules en die rede vir hul stabiliteit word egter nog nie ten volle verstaan nie. Volgens 'n hipotese deur Britz et al. (1999), vind 'n verskuiwing in die populasie dinamika van die anaerobiese gemeenskap plaas tydens die implementasie van omgewings 'stress' toestande. Die resultaat is 'n verhoging in ESP produksie en 'n gevolglike verbetering in die granulasie proses. In die tweede studie was dit gevind dat, wanneer 'stress' toestande op die reeds gevormde granulasie toegepas word, die Gram-positiewe laktaat-benuttende asetogeniese populasie voordeel geniet en meer propioonsuur produserende bakterieë was teenwoordig. Die propioonsuur en asynsuur konsentrasies het ook verhoog en met 'n gevolglike daling in die groei-medium se pH. Dit bevestig 'n gedeelte van die hipotese dat, wanneer die granules onder 'stress' geplaas word, die asetogeniese populasie dinamika verander en die laktaat-benuttende populasie reageer tot die gedeeltelike afname in pH. Die meer suur-tolerante propioonsuur produserende bakterieë verkry 'n kompeterende voordeel en gevolglik is daar 'n verhoging in propioonsuur konsentrasie. Propionibakterieë was gevoeg by die onbehandelde slyk gedurende die granule produksie proses, en daar is gevind dat meer aktiewe granules gevorm word as andersins. Dit is moontlik as gevolg van die die ESP produksie van propionibakterieë wat die granulasie versnel het. Verbeterde granulasie was dus verkry in die sisteme waar propionibakterieë bygevoeg is. Vetsuur analises het gedui dat die gevormde vetsure ook in korrelasie was met die model van granulasie. Goeie korrelasie was dus verkry tussen die hipotese en die eksperimentele data en die hipotese is gedeeltelik bewys in hierdie studie.

Thesis (MSc Food Sc )--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The potential use of the upflow anaerobic sludge blanket (UASB) bioreactor is limited by the extended start-up periods due to the time-consuming granulation process and the fact that seeding inoculum is not freely available in most developing countries like South Africa. The mass cultivation of granules would provide the waste water treatment industry with suitable seeding inoculum and, therefore, an efficient waste water treatment option would be more easily available. By applying 'stress' conditions on a bioreactor system seeded with raw anaerobic sludge, the population dynamics of the anaerobic community change and the acidogens start to produce extracellular polymers, which in turn enhance the granulation process by providing a matrix for the bacterial cells to adhere to. These "environmental stress" conditions include changes in the C:P:N ratio's. The aim of this study was, therefore, to assess the impact of different carbon and nitrogen sources on the enhancement of granulation in a batch system, and to determine the best preservation technique in terms of retainment of activity. It was found that the carbon source and concentration had a significant influence on batch granule enhancement. Low concentrations (2.g.l ̄ ¹) of glucose gave the best granule enhancement over a 14 day incubation period. Fruit cocktail effluent was found to be a cheap and effective carbon source for batch granule cultivation. It was found that different nitrogen sources did not have the same impact on granule enhancement, however, urea, at all concentrations tested, gave the best granule enhancement. A major problem encountered during the study was the standardisation of the inoculum. Significant granule enhancement comparisons between the different carbon sources were impeded by the lack of a suitable and reliable form of sludge standardisation. Future research needs to address this problem of the standardisation of the sludge inoculum as this would lead to more kinetically comparable results. Mass granule culturing will require granule preservation without risking the loss of activity. In the second study, six different preservation techniques and storage periods were evaluated in terms of the retainment of activity. These involved freeze-drying, vacuum freeze-drying, vacuum-drying, freezing, cold storage and room temperature preservation. Activity testing was used for comparing the efficiency of the different preservation techniques in terms of the tempo of biogas and methane production. Freeze-drying the granules, with storage for up to 90 days was found to give the best retainment of activity, followed by vacuum freeze-drying. The room temperature preserved samples showed a sudden increase in activity by day 120, which could possibly be explained by cell hydrolysis of the granules after day 90. The highest activity was achieved after 10 h of incubation, and it was, therefore, suggested that activity testing for evaluation purposes should use an incubation time of only 10 h. Furthermore, only the basic test medium with added glucose should be used for activity testing as it was observed that the addition of lactate and acetic acid played no decisive role in determining the level of activity of the granules. This study recommends the use of low concentrations of glucose for optimum granule enhancement during the mass cultivation of granules, and the addition of low concentrations of lactate to ensure a stable system with no acidification. It is also advisable to use a standardised sludge inoculum, as this will allow more efficient comparisons. Freeze-drying is recommended as preservationtechnique as this technique showed the best retainment of activity. A storage period of 90 days is, however, too short to be of much use for the industry. This will have to be investigated, together with the phenomenon of increased activity after 90 days as shown by the room temperature preserved granules. / AFRIKAANSE OPSOMMING: Die potensiële gebruik van die "uptflow anaerobic sludge blanket" (UASB) bioreaktor word beperk deur verlengde aansitprosedure as gevolg van die tydsame granulasieproses en die feit dat geskikte inokulums nie vrylik beskikbaar is in die meeste ontwikkelende lande, bv. Suid-Afrika nie. Die massa-kweking van granules sal die afvalwater-industrie voorsien van 'n geskikte inokulum, en sodoende 'n effektiewe opsie vir die behandeling van afvalwater beskikbaar stel. Deur die aanwending van "stres" toestande op 'n reaktor, wat geinokuleer is met rou anaerobe slyk, vind daar 'n verandering in die samestelling van die anaerobe populasie plaas. Die laktaat-benuttende asidogene begin om ekstrasellulêre polisakkariede te produseer wat die granulasieproses versnel deur 'n matriks te voorsien waaraan die bakteriële selle kan heg. Hierdie "omgewings stres" toestande sluit veranderinge in die C:P:N verhoudings in. Die doel van hierdie studie was om die invloed van verskillende koolstof- en stikstofbronne op die vermeerdering van granules te bepaal, asook om die beste preserveringstegniek in terme van die behoud van aktiwiteit te bepaal. Daar is gevind dat die koolstofbron en konsentrasie 'n betekenisvolle invloed op granule-vermeerdering het. Lae konsentrasies glukose (2 g.I ̄ ¹) het tot die grootste vermeerdering in granules oor 'n 14 dae inkubasieperiode gelei. Vrugtekelkie-afvalwater is geidentifiseer as 'n goedkoop en effektiewe koolstofbron wat ook gebruik kan word vir die kweking van granules. Voorts is gevind dat die stikstofbron en konsentrasie nie so 'n groot invloed op granule-vermeerdering het nie. Urea het nietemin die beste granule-vermeerdering vir al die konsentrasies wat getoets is, gegee. Standaardisasie van die inokulum was 'n groot probleem gedurende die studie. Betekenisvolle vergelykings tussen die granule-vermeerderings verkry met die verskeie groeimedia is bemoeilik deur die afwesigheid van 'n geskikte en betroubare standaardisasie-metode. Toekomstige navorsing moet hierdie probleem aanspreek aangesien dit sal lei tot meer kineties vergelykbare resultate. Massa-kweking van granule sal 'n metode van granule-preservering vereis sonder enige verlies van aktiwiteit. In die tweede studie is ses verskillende preserverings-tegnieke en opbergings-periodes in terme van die behoud van aktiwiteit geëvalueer. Die tegnieke sluit in: vriesdroging; vakuum-vriesdroging; vakuumdroging; bevriesing; koelopberging en kamertemperatuur-preservering. Aktiwiteitstoetsing is gebruik vir die vergelyking van die effektiwiteit tussen die verskillende preserverings-tegnieke in terme van die tempo van biogas- en metaanproduksie. Die granules wat met behulp van die vriesdroogtegniek gepreserveer is, het die beste behoud van aktiwiteit getoon, gevolg deur die vakuum-gevriesdroogde granules. Die monsters wat by kamertemperatuur gepreserveer is, het 'n skielike toename in aktiwiteit na 120 dae van opberging getoon en 'n moontlike verklaring vir hierdie verskynsel kan sel-hidrolise van die granules na 90 dae van opberging wees. Die meeste aktiwiteit is behaal na 'n 10 h inkubasietyd, en dus word hierdie inkubasietyd aanbeveel indien aktiwiteitstoetse vir evaluerings-doeleindes gedoen word. Verder word aanbeveel dat slegs die glukose-verrykte basiese toetsmedia vir aktiwiteitstoetsing gebruik word aangesien die byvoeging van laktaat en asynsuur geen noemenswaardige rol speel in die bepaling van die vlak van aktiwiteit van die granules nie. Hierdie studie beveel die gebruik van lae glukosekonsentrasies aan vir optimale vermeerdering van granules tydens die massakweking daarvan, asook die byvoeging van lae konsentrasies laktaat om 'n stabiele sisteem met geen versuring te verseker. Die gebruik van 'n gestandaardiseerde slyk-inokulum word sterk aanbeveel aangesien dit meer vergelykbare resultate lewer. Vriesdroging (as preserveringstegniek) het die beste behoud van aktiwiteit in die granules getoon en word dus as preserveringstegniek aanbeveel. 'n Opbergingsperiode van 90 dae is egter te kort om van veel waarde vir die industrie te wees. Hierdie probleem, asook die verskynsel van 'n verhoging in aktiwiteit na 90 dae van die granules wat by kamertemperatuur gepreserveer is, moet verder ondersoek word.

Thesis (MSc Food Sc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The wine industry significantly contributes to South Africa's water demand and subsequent pollution of the limited resource. Wastewater is produced throughout the year with an increase in volume and organic load during the vintage season. Anaerobic digestion (AD), specifically the upflow anaerobic sludge bed (UASB) technology has been shown to be feasible in the treatment of cellar wastewater. However, the legal standard for chemical oxygen demand (COD) for disposal in a natural water resource (75 rnq.L") is often not met. The aim of the study was to conduct a laboratory-scale investigation into the feasibility of combining pre- and post-ozonation processes with AD in order to achieve a final COD closer to the legal disposal limit. While acclimatising an UASB bioreactor containing mixed anaerobic granules to a cellar wastewater with a pH set at 8.0, stable-state conditions were not reached. Sucrose additions to the substrate, increased substrate loads, heattreatment of the substrate and an addition of isolated cellar effluent bacteria to facilitate degradation prior to AD, were all unsuccessful in maintaining stable-state in terms of COD removal efficiency. Once the substrate pH was re-set to 7.5, the reactor stabilised. The lowest efficient operational pH was found to be 5.73 resulting in a COD removal of 88% at a substrate COD < 5 000 rnq.L". At a substrate pH of 6.0, the lowest efficient operational hydraulic retention time (HRT) and corresponding organic loading rate (OLR) were 19.7 hand 9.75 kg COD.m-3d-1 , respectively, with the COD removal being maintained around 84%. The reactor effluent still had a final COD of 1280 rnq.L", which was well above the legal South African limit. Dominant bacteria were isolated from raw cellar wastewater and identified as Acinetobacter haemolyticus, Burkholderia cepacia and Cryseomonas luteola. In order to investigate the possibility that ozonation improved biodegradability, the growth of the isolates at 35°C was monitored over 24 h in sterile ozonated and non-ozonated substrates from the vintage and non-vintage seasons. All the isolates increased by at least 1.5 log cycles in the control substrates from both seasons. Ozonation of the wastewater batches for 10 min at a rate of 73 rnq.L" led to slightly increased growth of the inoculants in the substrate batch from the vintage season. For the substrates from the non-vintage season, ozonation had an inhibitory effect on the bacterial growth. A 5 min ozonation treatment at a concentration of 73 rnq.L" was found to be optimal for both a pre- and post-treatment to UASB-treatment of cellar wastewater. Both UASB treatment and ozonation were effective in reducing the COD by 85% and 20%, respectively. The COD reduction was improved to 88% when UASB treatment was combined with post-ozonation. The total reduction in total suspended solids (TSS) for the combined process was 97%, compared to 80% for UASB and 73% for an ozone treatment alone. The reduction for volatile suspended solids (VSS) was 98% compared to 81% for UASB and 73% for the ozone treatment alone. The total reduction when using a pre-ozonation UASB treatment combination was an average of 86% for COD. The TSS and VSS were both reduced by 95%. Biogas production increased from 1.4 L.d-1 to 3.8 L.d-1 when an ozonated wastewater was used as substrate. When the UASB treatment was combined with both a pre- and post-ozonation treatment process, the COD was reduced by 89% while TSS and VSS were both reduced by 99%. This study showed that pre- and post-ozonation treatment processes could successfully be utilised to improve UASB treatment of cellar wastewater. Although the legal limits for discarding into a natural resource were not met, significant progress was made in reducing COD levels. Cellar wastewaters do however, vary according to season and the wastewater composition could affect the efficiency of a pre-ozonation process. / AFRIKAANSE OPSOMMING: Die wynindustrie maak "n beduidende bydrae tot die eise wat aan Suid-Afrika se waterbronne gestel word en gevolglik die besoedeling van die beperkte hulpbron. Afloopwater, wat in volume en organiese lading gedurende die parstyd toeneem, word reg deur die jaar opgelewer. Anaërobiese vertering (AV), spesifiek die "Upflow anaerobic sludge blanket" (UASB) tegnologie, is alreeds suksesvol gebruik om kelderafloop te behandel. Die wetlike vereiste vir chemiese suurstof behoefte (CSB) vir storting in "n natuurlike hulpbron (75 rnq.L"), word egter dikwels nie bereik nie. Die doel van die studie was om in "n laboratorium-skaal ondersoek AV te kombineer met voor- en na-osoneringsprossesse, om sodoende te poog om "n CSB nader aan die wetlike standaard te verkry. Terwyl"n UASB bioreaktor wat gemengde anaerobiese granules bevat het, geakklimatiseer is tot kelderafloop met "n pH gestel tot 8.0, kon stabiele toestande nie bereik word nie. Die byvoeging van sukrose tot die substraat, verhoogde substraatladings, hitte-behandeling van die substraat en die byvoeging van geïsoleerde kelderafloop bakterië om substraatafbraak voor AV aan te help, was onsuksesvol om stabiliteit in terme van CSB-verwydering, te handhaaf. "n Verstelling van die substraat pH na 7.5, het gelei tot reaktorstabiliteit. By die laagste doeltreffende bedryfs-pH van 5.73 en substraat CSB < 5 000 rnq.L", was die CSB-verwydering 88%. By "n substraat pH van 6.0 was die laagste doeltreffende bedryfs-hidroliese retensie tyd en -organiese ladingstempo 19.7 h en 9.75 kg CSB.m-3d-1, onderskeidelik, terwyl die CSB verwydering rondom 84% gehandhaaf is. Die CSB van die reaktoruitvloesel van 1 280 rnq.L", was steeds ver bo die wetlike vereiste. Dominante bakterië is uit kelderafloop geïsoleer en as Acinetobacter haemolyticus, Burkholderia cepacia en Cryseomonas luteola, geïdentifiseer. Die moontlikheid dat osonering bioafbreekbaarheid bevorder, is ondersoek deur die groei van die isolate by 35°C oor 24 h in steriele geësoneerde en ongeësoneerde substrate te monitor. Die substrate is berei vanaf kelderafloop wat in die parsseisoen sowel as die nie-parsseisoen versamel is. AI die isolate het met ten minste 1.5 log siklusse in die kontrole substrate van beide seisoene, vermeerder. Vir die kelderafloop wat in die parsseisoen versamel is, het osonering vir 10 min teen 73 rnq.L" gelei tot effens verbeterde groei van die innokulante. Osonering het 'n onderdrukkende effek op die groei van bakterië in die afloopwater versamel in die nie-parsseisoen, gehad. Osonering vir 5 min teen 'n konsentrasie van 73 rnq.L" is as optimum vir beide voor- en na-osoneringsbehandeling tot UASB-behandeling van die kelderafloop, gevind. UASB-behandeling en osonering het die CSB met 85 en 20% onderskeidelik, verminder. Die vermindering kon tot 88% verhoog word wanneer UASB-behandeling met na-osonering gekombineer is. Die vermindering in totale gesuspendeerde vastestowwe (TGV) vir die gekombineerde proses was 97%, in vergelyking met 80% vir UASB- en 73% vir osoonbehandeling alleen. Die vermindering in vlugtige gesuspendeerde vastestowwe (VGV) was 98% in vergelyking met 81% vir UASB- en 73% vir osoonbehandeling alleen. Die totale CSB verwydering vir 'n voor-osonerings UASB kombinasie was gemiddeld 86%. Die TGV en VGV is beide met 95% verminder. Biogasproduksie het ook vermeerder vanaf 1.4 L.d-1 tot 3.8 L.d-1 toe geosoneerde afloopwater as substraat gebruik is. Die kombinasie van UASB-behandeling met voor-osonering, sowel as na-osonering het gelei tot 'n CSB-verwydering van 89% terwyl TGV en VGV beide met 99% verminder is. Hierdie studie het getoon dat voor- en na-osonering suksesvol gebruik kan word om UASB-behandeling van kelderafloop te verbeter. Hoewel wetlike vereistes vir storting in 'n natuurlike hulpbron nie bereik is nie, is beduidende vordering gemaak in die verlaging van CSB-vlakke. Die verskil in die samestelling van kelderafloop gedurende die onderskeie seisoene, kan egter die doeltreffendheid van die voor-osoneringsproses beïnvloed.

O presente trabalho estudou o aumento de capacidade de tratamento de um reator UASB (Upflow Anaerobic Sludge Blanket) por meio da adição de material suporte para adesão celular (Biobob®), avaliando-se as eficiências de remoção de matéria orgânica (expressa como DQO demanda química de oxigênio) e sólidos em suspensão (expressos como SST sólidos em suspensão totais). O reator híbrido, no qual a biomassa está presente em suspensão e imobilizada no material suporte, foi submetido a baixos tempos de detenção hidráulica (TDH) e altas velocidades ascensionais (vs). A operação do reator anaeróbio, de volume útil igual a 12,5 m³, foi conduzida em duas etapas. Na primeira o sistema foi operado como um reator de manta de lodo e escoamento ascendente (UASB), com TDH de 8,8 h e velocidade ascensional de 0,63 m.h-1. Na segunda etapa, introduziu-se 5,0 m³ de material suporte Biobob® no leito reacional do reator, transformando-o em reator anaeróbio híbrido (HAnR). Nessa condição, variou-se a vazão de alimentação, tendo o TDH variado entre 7,4 h (vs de 0,66 m.h-1) a 3,9 h (vs de 1,25 m.h-1). Para ambas as etapas o sistema foi alimentado com esgoto sanitário à temperatura ambiente, após tratamento preliminar (gradeamento e caixa de areia). Para condições de operação similares, o reator anaeróbio híbrido (HAnR) apresentou melhor desempenho na remoção de DQO e SST que o reator UASB, acrescendo em até 18% e 30% a eficiência de remoção, respectivamente. Para a velocidade ascensional de 1,25±0,02 m.h-1 e TDH de 3,9±0,1 h, o HAnR apresentou concentrações médias no efluente tratado de 205±46 mg DQOt.L-1 e 73±30 mg SST.L-1 e eficiências de remoção de 55±9% DQOt e 63±14% SST. / The increase of the treatability capacity of a UASB (Upflow Anaerobic Sludge Blanket) reactor by introducing an innovative packing material (Biobob®) in its reaction zone was evaluated. The hybrid anaerobic reactor (HAnR) containing suspended and immobilized biomass was evaluated regarding its efficiency of removing organic matter (expressed as COD chemical oxygen demand) and suspended solids (expressed as TSS total suspended solids) under lower hydraulic detention time (HDT) and higher upflow velocities (v s). The anaerobic reactor operation, with 12.5 m³ of working volume, was conducted in two phases. In the first phase, the system was operated as a conventional UASB reactor with HRT of 8.8 h and vs of 0.63 m.h -1 . In the second phase, 5.0 m³ of packing material Biobob® was introduced inside the reaction bed, changing the reactor configuration from suspended growth to hybrid growth. In this condition, the hybrid anaerobic reactor (HAnR) was subjected to decreasing flowrates with HDT ranging from 7.4 h (vs of 0.66 m.h-1) to 3.9 h (vs of 1.25 m.h-1). For both phases, the feed was domestic wastewater (after screens and grit chambers) at ambient temperature. Under similar operation conditions, the HAnR performed better than the UASB reactor increasing at 18% and 30% the COD and TSS removal efficiencies, respectively. For vs of 1.25±0.02 m.h-1 and HDT of 3.9±1.0 h, the HAnR produced a very high quality effluent, with average COD and TSS concentration of 205±46 mg DQOt.L-1 and 73±30 mg SST.L-1 and removal efficiencies of 55±9% and 63±14% for CODt and SST, respectively.

A presente pesquisa avaliou diferentes razões de recirculação do meio líquido com a finalidade de identificar a melhor condição de mistura para uma produção elevada e contínua de hidrogênio em um reator anaeróbio de leito fixo com fluxo ascendente alimentado com um meio contendo sacarose como fonte de carbono e uréia como fonte de nitrogênio. Foi utilizado polietileno de baixa densidade como meio suporte para imobilização da biomassa. O experimento foi iniciado com ensaios hidrodinâmicos (pulso, utilizando dextran blue como traçador) que determinaram as seguintes razões de recirculação em relação à vazão de alimentação utilizadas: R = 0,25, 0,5, 1,0 e 2,0. O experimento foi realizado em duas etapas, nas quais foram operados dois reatores idênticos simultaneamente, testando-se duas razões de recirculação diferentes. A DQO da água residuária foi de 2000 mg/L. O tempo de detenção hidráulica teórico foi de 2 horas e a temperatura foi mantida em 25 graus Celsius. A remoção de sacarose apresentou valores médios de 67%, 79%, 71% e 70% para R = 0,25, 0,5, 1,0 e 2,0, respectivamente. Os valores médios de rendimento de hidrogênio foram 1,14 mol \'H IND.2\'/mol sac, 1,43 mol \'H IND.2\'/mol sac, 1,34 mol \'H IND.2\'/mol sac e 0,86 mol \'H IND.2\'/.mol sac e de produção volumétrica de hidrogênio foram 74,34 mL \'H IND.2\'/(h.L), 124,78 mL \'H IND.2\'/(h.L), 96,57 mL \'H IND.2\'/(h.L) e 73,49 mL \'H IND.2\'/(h.L) para as vazões de recirculação de 0,25, 0,5, 1,0 e 2,0, respectivamente. O biogás produzido foi composto de \'H IND.2\', e \'CO IND.2\', com valores percentuais médios para \'H IND.2\', de 50%, 56%, 56% e 46% para R = 0,25, 0,5, 1,0 e 2,0, respectivamente. Não houve presença de metano em nenhuma fase de operação. Os principais produtos intermediários produzidos durante a produção de \'H IND.2\', foram ácido acético, ácido butírico e etanol, de forma similar para todas as fases de recirculação. Analisando todos os parâmetros de operação, foi possível notar que a melhor vazão de recirculação obtida foi de R = 0,5. Ajustando os dados obtidos a uma função polinomial, porém, chegou-se a um ponto de ótimo em R = 0,6. Durante os experimentos observou-se uma queda na produção do biogás, provavelmente por atuação de microrganismos consumidores deste. / The present research evaluated different recirculation rates of the liquid medium for the purpose of identify the best mixture condition for a high and continuous hydrogen production in an anaerobic upflow fixed-bed reactor fed with a medium containing sucrose as carbon source and urea as nitrogen source. Low density polyethylene was used as medium for biomass immobilization. The experiment began with hydrodynamic tests (pulse, using dextran blue as tracer) which led to the following recirculation rates related with the feed flow rate used in this work: R = 0,25, 0,5, 1,0 and 2,0. The experiment was conducted in two stages, where two identical reactors were operated simultaneously, by testing two different recirculation rates. COD from wastewater was 2000 mg/L. The theoretical hydraulic retention time was 2 hours and the temperature was maintained at 25 Celsius degrees. The average values of sucrose consumption were 67%, 79%, 71% and 70% for R = 0,25, 0,5, 1,0 and 2,0, respectively. The average values of hydrogen yield were 1,14 mol \'H IND.2\'/mol sac, 1,43 mol \'H IND.2\'/mol sac, 1,34 mol \'H IND.2\'/mol sac and 0,86 mol \'H IND.2\'/mol sac and of hydrogen production rate were 74.34 mL \'H IND.2\'/(h.L), 124.78 mL \'H IND.2\'/(h.L), 96.57 mL \'H IND.2\'/(h.L) and 73.49 mL \'H IND.2\'/(h.L) for recirculation rates of 0.25, 0.5, 1.0 and 2.0, respectively. The biogas produced was composed by \'H IND.2\', and \'CO IND.2\', with average values for \'H IND.2\', of 50%, 56%, 56% and 46% for R = 0,25, 0,5, 1,0 and 2,0, respectively. Methane was not detected. The main intermediate products produced during the hydrogen production were acetic acid, butyric acid and ethanol, similar in all stages of recirculation. Analyzing all operating parameters, it was identified that the better recirculation rate obtained during the experiments was R = 0.5. Adjusting all data obtained with a polynomial function, it was found an optimal recirculation rate of R = 0.6. During the experiments there was a drop in biogas production, probably by the activity of microrganisms consumers of this biogas.

Modelos matemáticos oferecem grandes benefícios para a compreensão dos mecanismos envolvidos nos processos de tratamento de águas residuárias uma vez que fornecem interpretações e possibilitam previsões de desempenho, comparações de alternativas de tratamento, otimização de futuras plantas ou o aprimoramento das existentes, podendo subsidiar a elaboração de projetos em escala real. Em virtude disto, nesta pesquisa visou-se o desenvolvimento de um modelo bioquímico-matemático para descrever o processo de degradação da glicose em um reator anaeróbio de leito fixo com fluxo ascendente, com a resultante produção biológica de hidrogênio por meio do processo de fermentação. O desenvolvimento do modelo foi baseado em estudos sobre a cinética bioquímica e as características hidrodinâmicas do sistema. Os parâmetros de ajuste do modelo aos dados experimentais foram as constantes de velocidade das reações bioquímicas envolvidas na produção de hidrogênio. A calibração foi realizada manualmente buscando minimizar o desvio global. Para a determinação dos parâmetros foi utilizada a técnica de geração de números aleatórios com distribuição de freqüência uniforme e em seguida, o método de inversão de matrizes. O modelo matemático se revelou bastante adequado para a previsão do perfil de concentrações ao longo do reator, e possibilitou a representação das rotas de utilização da matéria orgânica. A reação de oxidação do ácido propiônico pelas bactérias acidogênicas produtoras de hidrogênio constitui a principal via de produção de \'H IND.2\' no sistema. / Mathematical models bring benefits to the understanding of mechanisms involved on wastewater treatment processes because they provide interpretations and make possible performance predictions, evaluation of design alternatives, optimization of future plants or the improvement to existing systems. Therefore, in this work a mathematical model to describe the glucose degradation process, with hydrogen production through the fermentation, in an upflow anaerobic packed-bed reactor is developed. The model equations were based on studies of biochemical kinetics and hydrodynamics features of the system. The parameters considered were the rates of the biochemical reactions involved in the hydrogen production. The calibration was made through the minimization of the global deviation. The parameters determination was obtained with the use of a technique of generation of aleatory numbers, and after that, the method of matrices inversion for the solution of the system of linear equations. The mathematical model developed showed to be adequate for the concentrations prediction along the reactor, and it made possible the representation of the routes of organic material utilization. The oxidation reaction of propionic acid is the main hydrogen production route in the reactor.

A dupla filtração pode ser considerada como uma das mais promissoras tecnologias para tratamento de água, estimando-se que grande parte das necessidades de tratamento poderiam ser satisfeitas com o uso desta tecnologia. Alguns aspectos ainda não devidamente esclarecidos até o presente sobre esta tecnologia estão relacionados ao tratamento de água com turbidez elevada. Com a montagem e operação de uma instalação piloto, constituída de dois sistemas de dupla filtração (sistema 1: filtro ascendente de areia grossa e filtro descendente de areia e sistema 2: filtro ascendente de pedregulho e filtro descendente de areia), foi realizada uma investigação experimental com águas de estudo preparadas com caulinita (água tipo I com turbidez em torno de 100 uT e água tipo II com turbidez em torno de 300 uT). A coagulação foi realizada com o sulfato de alumínio, sem o uso de alcalinizante ou de acidificante, para que resultasse potencial zeta próximo de zero. A operação de ambos os sistemas foi efetuada com e sem descargas de fundo intermediárias nos filtros ascendentes, e foram variadas as taxas de filtração em ambos os filtros (de 120 a 240 m&sup3/m&sup2.d nos filtros ascendentes e de 180 a 300 m&sup3/m&sup2.d nos filtros descendentes). Concluiu-se principalmente que os dois sistemas foram capazes de produzir água filtrada com turbidez consistentemente menor que 0,5 uT e que a produção efetiva de água depende da turbidez da água de estudo, das taxas de filtração, da execução das descargas de fundo intermediárias e da carga hidráulica disponível para retenção de sólidos. / Double filtration may be considered one of the most important technologies for water treatment. It has been estimated that most of water treatment can be efficiently achieved with the use of this technology, although some design and operational aspects related to the high turbidity of the influent water have not been fully studied until the present time. A pilot plant was built comprising two double filtration systems (system 1 with an upflow coarse sand filter followed by a downflow fine sand filter; system 2 with an upflow gravel filter followed by a downflow filter identical to that used in system 1). The experimental investigation was carried out using influent waters prepared with kaolin (water type I with turbidity of approximately 100 NTU and water type II with turbidity of approximately 300 NTU). Coagulation was accomplished by using aluminum sulfate (no acid or alkaline products) so that the zeta potential resulted approximately zero. The operation of both systems was carried out with and without intermediate down flushes during the runs. Filtration rates in the filters of both systems varied from 120 to 240 m&sup3/m&sup2.d in the upflow filters and from 180 to 300 m&sup3/m&sup2.d in downflow filters. It was mainly concluded that both systems resulted capable to produce filtered water with turbidity consistently lower than 0.5 NTU and that the net production was related to the influent water turbidity, filtration rates, execution of intermediate down flushes and the hydraulic head provided for solids retention in both filter of each double filtration system.