The study analyses the relative separation of the effects of changes in a nation's dollar exchange rate and crude oil's dollar price on a country's short-run crude oil derived demand. It examines the role of the dollar exchange rate on domestic and international petroleum flows and discusses the short-run inefficiencies that occur due to adjustment times in a country's domestic petroleum market. A four-equation, structural model of a country's short-run petroleum demand function for its two petroleum flows (crude oil and imported product) was used. Using the translog function, estimates of direct and indirect dollar exchange rate effects were estimated. To account for the role of a nation's refinery industry on international petroleum flows, a measure of the industry's flexibility was developed. The industry is said to be flexible when it can alter its inputs' naturally occurring product fractions to more closely meet the country's final demand. The index developed in this study measures the industry's increase in its output product slate's weighted average API, relative to the weighted average API of its crude oil and feedstocks inputs, adjusted for the crude oil's naturally occurring product fractions.

This dissertation studies the oil-mediated relationship between the Indian state and citizens. Focusing on both oil production and consumption, through 24 months of ethnography of oil refineries, ports, research institutes, state offices, a peri-urban working-class-neighborhood near Delhi (called Nathupur), and ‘black markets’, as well as archival research, this project examines oil as an infrastructure for the state and for society. I argue that the Indian state distributes itself into citizens’ lives via petroleum products, which obtain their socio-political agencies while being produced in certain ways, and play out those agencies while being consumed in certain ways. This ethnography of refineries details out the microprocesses of oil refining and the complex relationship that human and nonhuman actors share. It elaborates on how politics get programmed into petroleum products, designed to discipline consumer-citizens into particular lifestyles, and how varying actors encumber this. Research on oil consumption in Nathupur, with ‘black-marketeers’ and ordinary consumers of petroleum products, probes what I call “distorted discipline”, where governmental plans get mangled by the informal practices of state actors as well as citizens. How does the politics programmed into petroleum products in refineries actually play out once other actors intervene, and snatch control over oil away from the state? Investigating this tussle between legalized and illegalized groups, I describe how it structures citizens’ lives, and the constellations of power and forms of sociality it gives rise to. This dissertation highlights the constant churning between the state and citizens through ever-evolving devices of government, as well as through escape from them. Specific modes of subjectification, engineered through flows of oil, lie at the heart of this churning, over which state-citizen formations are negotiated.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Sulphuric acid/oxygen pressure leaching is typically employed on Base Metal Refineries (BMRs) to selectively dissolve base metals from platinum group metal (PGM) bearing nickelcopper matte. Optimal operation of this processing step requires an understanding of the system chemistry and the effects of process variables on base metal and PGM leaching behaviour. This project aimed to aid in the development of an improved understanding of the high pressure leaching system. The effects of temperature, pressure, acid concentration, and solid to liquid ratio on the leaching behaviour were determined experimentally using a two litre autoclave. For conditions comparable to that typically used at the Western Platinum Ltd. BMR, changes in the acid concentration had the largest effect on the copper leaching behaviour. Increasing the initial acid concentration from 140 g H2SO4/ℓ to 165 g H2SO4/ℓ resulted in the copper dissolution decreasing from 88.7% to 75.3% on average for the experiments performed at different temperatures (116°C, 130°C) and pressures (7 bar, 9 bar), and with different solids contents (80 g/ℓ, 130 g/ℓ). In the case of the other precious metals (OPMs), temperature was determined to be the process variable with the largest effect on the leaching kinetics. The average percentage rhodium dissolution achieved after seven hours of leaching at different conditions (pressure, acid concentration, and solids content were varied) increased from 58.3% at 116°C to 83.6% at 130°C. Similar effects were observed for ruthenium (96.2% dissolution at 130°C; 79.4% dissolution at 116°C) and iridium (81.8% dissolution at 130°C; 46.9% dissolution at 116°C). The rate of copper leaching was found to be limited by the rate of oxygen transfer from the gaseous phase to the liquid phase, while the remainder of the reactions were chemical reaction limited. The extent of OPM leaching was found to be dependent on the rate and extent of copper leaching. A set of 21 chemical reactions was proposed to describe the leaching behaviour, and the shape factors and reaction rate constants were determined by the method of least squares to minimise the error between the predicted concentrations and the experimental data. Apart from direct base metal leaching reactions, six cationic exchange reactions contribute to the leaching of copper sulphides and nickel sulphides by precipitation of OPM oxides. Three leaching reactions for each of the OPMs (one for sulphide phases, one for metallic phases, and one for oxide phases) resulted in satisfactory modelling of the system behaviour. Activation energies of -26.2 kJ/mol and -5.9 kJ/mol were calculated for the digenite acid leaching reaction and the covellite direct oxidation reaction, respectively, which confirmed that the rates of these reactions were mass transfer limited. The activation energies for the remainder of the base metal leaching reactions exceeded 30 kJ/mol. The activation energies of the reactions accounting for rhodium sulphide leaching, rhodium leaching, and rhodium oxide leaching, were calculated to be 64.2 kJ/mol, 138.5 kJ/mol, and 116.2 kJ/mol, respectively. Similar activation energies were calculated for the respective Ru and Ir leaching reactions. The rate of OPM sulphide leaching was typically an order of magnitude and three orders of magnitude larger than the rate of OPM leaching reactions and OPM oxide leaching reactions, respectively. The autoclave at the Western Platinum Ltd. BMR was modelled assuming a monosized distribution of the feed and approximating the autoclave as four ideal continuously stirred tank reactors. The steady state solution employed the sequential modular approach in MATLAB, while the dynamic simulation involved solving a set of 217 differential equations derived from mass and energy balances simultaneously in MATLAB. The model was used successfully to evaluate the effects that changes in the leaching temperature, leaching pressure, acid feed rate, and solids feed rate have on the extent of base metal and OPM leaching in the autoclave. The optimum operating conditions depend on the flow rates and compositions of the feed streams. A feed stream containing 10.3 wt% solids (825 kg solids/h) and an acid addition rate of 28.6 kg/h were considered as typical operating conditions for model-based analysis. More than 95% copper dissolution and no OPM dissolution were predicted when performing the pressure leaching at a pressure of 8 bar and a temperature of approximately 123°C. Decreasing the pressure resulted in lower copper dissolution when OPM leaching started to occur. Increasing the temperature resulted in reduced copper leaching, while decreasing the temperature resulted in a longer OPM leaching period and hence higher OPM dissolution. Model-based analysis furthermore showed that the relative amounts and relative leaching rates of digenite and covellite significantly influence the percentage copper dissolution achieved when noticeable OPM leaching start to occur. / AFRIKAANSE OPSOMMING: Swawelsuur/suurstof hoë druk loging word tipies op Basis Metaal Raffinaderye (BMRe) gebruik om basis metale selektief op te los vanuit platinum groep metaal (PGM) bevattende nikkel-koper mat. Optimale bedryf van hierdie prosesstap vereis ʼn begrip van die sisteem se chemie en die effekte wat proses veranderlikes op die logingsgedrag van basis metale en PGMe het. Hierdie projek het ten doel gehad om ʼn beter begrip van die hoë druk loging sisteem te ontwikkel. Die effekte van temperatuur, druk, suur konsentrasie, en vastestof tot vloeistof verhouding op die logingsgedrag is eksperimenteel met behulp van ʼn twee liter outoklaaf bepaal. Vir toestande vergelykbaar met dié wat tipies by die Western Platinum Bpk. BMR gebruik word, het veranderinge in die suurkonsentrasie die grootste effek op die logingsgedrag van koper gehad. Verhoging van die aanvanklike suurkonsentrasie van 140 g H2SO4/ℓ na 165 g H2SO4/ℓ het tot gevolg gehad dat die gemiddelde koper oplossing afgeneem het van 88.7% na 75.3% vir die eksperimente wat by verskillende temperature (116°C, 130°C) en drukke (7 bar, 9 bar), en met verskillende vastestof inhoud (80 g/ℓ, 130 g/ℓ), uitgevoer is. In die geval van die ander edelmetale (AEM) is bevind dat die temperatuur die prosesveranderlike met die grootste effek op die logingskinetika is. Die gemiddelde persentasie rodium oplossing wat na sewe ure se loging by verskillende toestande (druk, suurkonsentrasie, en vastestof inhoud is varieer) behaal is, het toegeneem van 58.3% by 116°C na 83.6% by 130°C. Soortgelyke effekte is waargeneem vir rutenium (96.2% oplossing by 130°C; 79.4% oplossing by 116°C) en iridium (81.8% oplossing by 130°C; 46.9% oplossing by 116°C). Dit is bevind dat die tempo van koper loging beperk is deur die tempo van suurstof oordrag vanaf die gas na die vloeistoffase, terwyl chemiese reaksies beperkend was vir die res van die reaksies. Die mate van AEM loging was afhanklik van die tempo en mate van koper loging. ʼn Stel van 21 reaksies is voorgestel om die logingsgedrag te beskryf, en die vorm faktore en reaksie tempo konstantes is bepaal deur middel van die metode van kleinste kwadrate om die fout tussen die voorspelde konsentrasies en die eksperimentele data te minimeer. Afgesien van die direkte basis metaal logingsreaksies het ses kationiese uitruilingsreaksies bygedra tot die loging van kopersulfiede en nikkelsulfiede deur presipitasie van AEM oksiede. Drie logingsreaksies vir elk van die AEMe (een vir die sulfied fase, een vir die metaal fase, en een vir die oksied fase) het bevredigende modellering van die sisteem se gedrag tot gevolg gehad. Aktiveringsenergieë van -26.2 kJ/mol en -5.9 kJ/mol is bereken vir die Cu1.8S suur logingsreaksie en die CuS direkte oksidasie reaksie, onderskeidelik, wat bevestig het dat die tempo’s van hierdie reaksies deur massa oordrag beperk is. Die aktiveringsenergieë vir die res van die basis metaal logingsreaksies het 30 kJ/mol oorskry. Die aktiveringsenergieë vir die reaksies wat die rodiumsulfied loging, rodium loging, en rodiumoksied loging beskryf is as 64.2 kJ/mol, 138.5 kJ/mol, en 116.2 kJ/mol, onderskeidelik, bereken. Soortgelyke aktiveringsenergieë is bereken vir die onderskeie Ru en Ir logingsreaksies. Die tempo van AEM sulfied loging was tipies ʼn ordegrootte en drie ordegroottes groter as die tempo van AEM logingsreaksie en AEM oksied logingsreaksies, onderskeidelik. Die outoklaaf by die Western Platinum Bpk. BMR is gemodelleer deur ʼn enkelgrootte verspreiding vir die voer te aanvaar en die outoklaaf as vier ideale kontinu geroerde tenk reaktore te benader. Die oplossing vir gestadige toestande het die sekwensiële modulêre benadering toegepas in MATLAB, terwyl die dinamiese simulasie die gelyktydige oplos van 217 differensiale vergelykings, wat vanaf massa- en energiebalanse afgelei is, in MATLAB behels het. Die model is suksesvol gebruik om die effekte wat veranderinge in die logingstemperatuur, logingsdruk, suur voertempo, en vastestof voertempo op die mate van basis metaal en AEM loging in die outoklaaf het, te bepaal. Die optimale bedryfstoestande is afhanklik van die vloeitempo’s en samestellings van die voerstrome. ʼn Voerstroom wat 10.3 massa% vastestof (825 kg vastestof per uur) bevat en ʼn suur voertempo van 28.6 kg/h is as tipiese bedryfstoestande beskou vir model-gebaseerde analises. Meer as 95% koper oplossing sonder enige AEM oplossing is voorspel wanneer die loging by ʼn druk van 8 bar en ʼn temperatuur van ongeveer 123°C uitgevoer word. ʼn Vermindering van die druk het tot gevolg gehad dat laer koper loging behaal is toe AEM loging begin plaasvind het. ʼn Verhoging in die temperatuur het laer koper loging tot gevolg gehad, terwyl laer temperature ʼn langer AEM logingsperiode en gevolglik hoër AEM loging tot gevolg het. Model-gebaseerde analises het verder getoon dat die relatiewe hoeveelhede en relatiewe tempo’s van loging van Cu1.8S en CuS ʼn beduidende invloed het op die persentasie koper wat geloog is wanneer beduidende AEM loging begin plaasvind.

Em face ao aumento do preço de energia e combustíveis fósseis o conceito de biorrefinaria vem sendo foco de atenção das indústrias de celulose e papel. Esse conceito visa a obtenção de co-produtos a partir de um processo industrial pré-estabelecido sendo necessários alguns ajustes e investimentos. A possibilidade de recuperação do metanol contido no licor negro traz ao setor de celulose e papel o conceito de biorrefinaria florestal. O metanol celulósico contido no licor negro de fábricas de celulose e papel é o principal composto orgânico volátil responsável por mais de 90 % das emissões nessas fábricas. De forma semelhante aos compostos reduzidos de enxofre a formação do metanol ocorre durante a polpação alcalina em digestores, mas seu potencial para recuperação é desconhecido. Por isso, este trabalho teve como finalidade quantificar o metanol presente nos licores negros industriais provenientes de processo de polpação kraft convencional. Os licores negros industriais foram cedidos por fábricas brasileiras de celulose e papel. Para a quantificação desse álcool um método analítico foi otimizado e validado. Além disso, realizou-se o estudo de formação do metanol em licor negro durante a polpação alcalina para verificação dos parâmetros que determinam a concentração desse álcool no licor. O método otimizado mostrouse adequado à análise de metanol em licor negro e com potencial para amostras de condensados. A quantidade de metanol determinada em licor negro industrial mostrou-se passível de recuperação e sua formação durante a polpação foi influenciada pela intensidade da deslignificação do processo. / Given the rising price of energy and fossil fuels the concept of bio-refinery has been the focus of attention from the pulp and paper industries. This concept aims to achieve by-products from a pre-established industrial process which requires adjustments and investments. The recoverability of methanol contained in black liquor brings to the pulp and paper business sector the concept of forest bio-refinery. The cellulosic methanol contained in black liquor from pulp and paper mills is the main volatile organic compound responsible for more than 90% of emissions in these processing plants. Similarly to reduced sulfur compounds, the formation of methanol occurs during alkaline pulping in digesters but its potential for recovery is unknown. Therefore, this work aimed at quantifying the methanol present in industrial black liquor from conventional kraft pulping process. The black liquors were provided by Brazilian pulp and paper mills. To quantify this alcohol, an analytical method was optimized and validated. Moreover, we carried out a study on formation of methanol in black liquor during the alkaline pulping to specify the parameters to determine the concentration of this alcohol in the black liquor. The optimized method was adequate for the analysis of methanol in black liquor and showed potential to evaluate samples of condensates. The amount of methanol in black liquor has shown to be able to be recovered and its formation during pulping was influenced by the intensity of the delignification process.

A cultura da cana-de-açúcar tem grande relevância na economia brasileira. A agroindústria sucroenergética origina uma grande quantidade de sub-produtos, como o bagaço e a palha. Vários estudos têm sido conduzidos no intuito de utilizálos como matéria-prima para a obtenção de diversos produtos, como o etanol celulósico, energia e diversos compostos de interesse industrial. As biomassas lignocelulósicas, como o bagaço da cana, são compostas principalmente de celulose, hemicelulose e lignina, sendo que a proporção de cada componente é dependente de diversos fatores. No caso da cana, há variedades que apresentam diferentes teores de fibra e, ao pensar em utilizar o material residual para geração de produtos de maior valor agregado, é muito importante conhecer a composição dessa fibra. A celulose é um polímero de glicose unido por ligações glicosídicas ?1-4, rígida e muito resistente à hidrólise. A hemicelulose é um polímero de baixa massa molecular composta por pentoses, hexoses, e/ou ácidos urônicos e mais susceptível à hidrólise quando comparada à celulose, uma vez que apresenta menor grau de polimerização. Por fim, a lignina é uma substância hidrofóbica, com estrutura tridimensional e amorfa, altamente ramificada e sintetizada a partir de três precursores, o álcool coniferílico, o álcool sinapílico e o álcool p-cumarílico. Vários compostos de interesse têm sido descobertos nas biomassas lignocelulósicas, neste contexto surgem as biorrefinarias, onde são obtidos produtos de elevado valor agregado e energia por rotas bioquímicas ou termoquímicas e de maneira sustentável. A classificação proposta no trabalho objetiva padronizar posteriores discussões relacionadas à classificação da fibra da cana e auxiliar os melhoristas na obtenção de novas variedades comerciais. O propósito do estudo foi avaliar a constituição da fibra de diversos genótipos de cana-de-açúcar com altos teores de fibra, propor um modelo para classificação da cana-de-açúcar de acordo com a composição dessa fibra e investigar o potencial dos genótipos analisados para uso em biorrefinarias na obtenção de produtos como etanol de segunda geração, polietileno verde e xilitol. Os resultados obtidos indicaram que o genótipo 196 foi o que apresentou a maior porcentagem de celulose (54,18 %) e o 192 foi o que apresentou a menor quantidade desse componente (26,47 %). Em relação à hemicelulose, o genótipo 77 foi o que apresentou o maior (25,97 %) teor e o 167 (16,71 %) o menor. Por fim, o genótipo 166 (27,13 %) foi o que apresentou maior quantia de lignina em sua composição e o 27 (17,7 %) a menor. Em relação à classificação, a maior parte dos genótipos analisados foram classificados como C2H4L4, ou seja, apresentam de 40 a 50 % de celulose, de 20 a 25 % de hemicelulose e de 20 a 25 % de lignina na composição da fibra. No contexto de biorrefinarias, o genótipo 196 mostrou maior potencial para obtenção do etanol celulósico e do polietileno verde, uma vez que apresentou maior teor de celulose na fibra. Para obtenção do xilitol, o genótipo 77 se mostrou mais promissor, pois demonstrou possuir maior quantidade de hemicelulose em sua composição. / Sugarcane farming plays an important role in the Brazilian agribusiness. The agro-industrial energy sector generates a number of by-products, such as bagasse and straw. Several studies were conducted to investigate the use of bagasse and straw as raw material for the production of various products, such as cellulosic ethanol, energy and several compounds for industrial use. The lignocelullosic biomasses, such as sugarcane bagasse, are composed primarily of cellulose, hemicellulose and lignin, and the content of each component depends on several factors. There are varieties of sugarcane plants with different fiber contents and to use the residual material to generate high value-added products, it is very important to know the fiber composition. Cellulose is a glucose polymer linked by glycosidic ?1- 4 bonds, rigid and very resistant to hydrolysis. Hemicellulose is a low-molecularweight polymer composed of pentoses, hexoses and/or uronic acids and more susceptible to hydrolysis when compared to cellulose, since it has a lower polymerization degree. Finally, lignin is a hydrophobic substance, with threedimensional and amorphous structure, highly branched and synthesized from three precursors, coniferyl alcohol, sinapyl alcohol and P-Coumaryl alcohol. Several compounds of interest have been discovered in lignocelullosic biomasses, and biorefineries are important to produce high value-added products and energy by biochemical or thermochemical routes in a sustainable way. The classification proposed in this study aims to standardize further discussions on the classification of the sugarcane fibers and helps plant breeders to obtain new commercial varieties. The purpose of this study was to evaluate the fiber composition of several sugarcane genotypes with high fiber contents; propose a model for sugarcane classification according to the fiber composition of the cultivar and investigate the potential of the genotypes analyzed to be used bio-refineries to obtain products such as the secondgeneration ethanol, green polyethylene and xylitol. There were investigated an access group of 207 genotypes. We used high-performance liquid chromatography to characterize cellulose and hemicellulose, and spectrophotometry to analyze the lignin content. The results showed that genotype 192 had the highest cellulose content (54,18 %) and 196 had the lowest (26,47 %). Genotype 77 showed the highest hemicellulose content (25,97 %) and 167 had the lowest (16,71%). Genotype 166 showed the highest lignin content (27,13 %) in its composition and 27 had the lowest (17,7 %). Most of the analyzed genotypes were classified as C2H4L4, that is, containing 40-50 % of cellulose, 20-25 % of hemicellulose and 20-25 % of lignin in the fiber composition. For the bio-refineries, genotype 192 showed the greatest potential for the production of cellulosic ethanol and green polyethylene due to its higher cellulose content in the fiber. To obtain xylitol, genotype 77 was more promising, because of the higher hemicellulose content in its composition.

A proposta desta pesquisa foi avaliar a utilização de um sistema combinado de filtro anaeróbio (FAN) com filtro aeróbio (FAE) submerso ligados em série, ambos usando espuma de poliuretano como meio suporte e com fluxo ascendente, como alternativa para remoção matéria orgânica (DQO) e compostos nitrogenados em efluentes de refinarias de petróleo, além da redução da toxicidade do efluente ao micro crustáceo Mysidopsis juniae. O experimento durou 324 dias e foi divido em duas etapas. Inicialmente, o sistema foi operado por 129 dias sem recirculação entre os filtros e nesta etapa houve acréscimo de 12% nas concentrações de amônia no FAN e remoção de 80% no FAE. Quando se usou bicarbonato de sódio para alcalinizar o afluente ao sistema para manter o pH no FAE na neutralidade e alcalinidade acima de 107 mg\'CA\'CO IND.3\'/L, pôde-se alcançar remoções de amônia próxima a 100%. Quanto à remoção de DQO, o filtro anaeróbio removeu 40% e o aeróbio 65%. Em síntese, na primeira etapa o sistema removeu 80% de DQO, 89% de amônia e 35% de nitrogênio. A segunda etapa durou 195 dias e houve recirculação do efluente do filtro aeróbio para o filtro anaeróbio. Nesta etapa, o pH foi mantido na neutralidade e a recirculação foi feita de duas formas. A primeira com recirculação direta entre os filtros a uma razão (R) de reciclo de 2,0 resultou em 43% de remoção de amônia no FAN e 97% no FAE e com esta forma de reciclo houve 62,6% de remoção de nitrogênio total no sistema. A segunda forma de recirculação foi direcionar parte do efluente do filtro aeróbio ao reservatório do afluente ao sistema com R igual a 1,0 resultando em produção de amônia no FAN em 10% e remoção no FAE de, aproximadamente, 100%. Independentemente da forma de recirculação a remoção de DQO foi de 67% e 56% no filtro anaeróbio e aeróbio, respectivamente. A remoção de nitratos no FAN foi de 93% e foi independente da forma de reciclo. Houve 42,5% de remoção de nitrogênio no sistema. Na segunda etapa obtiveram-se as melhores remoções de DQO, amônia e nitrogênio, porém, tanto o afluente quanto o efluente final apresentou CL50 de 0,83% ao microcrustáceo M. juniae, assim, ambas as formas do efluente estão em desacordo com a resolução CONAMA 357/05. Os gêneros Aeromonas, Serratia e Pseudomonas foram dominantes no FAE ao fim da pesquisa. / The purpose of this study was to evaluate the use of a combined system comprised of an anaerobic filter (ANF) and a submerged aerobic filter (SAF) connected in series, both using polyurethane foam as support media and operated in a upflow mode, as an alternative for removing organic matter (COD) and nitrogen compounds in effluents from oil refineries, as well as reducing effluent toxicity to micro crustacean Mysidopsis juniae. The experiment lasted 324 days and was divided into two stages. Initially, the system was operated for 129 days without recirculation between the filters. During this stage, there was an increase of 12% on the ammonia content in the ANF followed by a removal of 80% in the SAF. When sodium bicarbonate was used to alkalize the influent to maintain the pH in the ANF close to neutral and alkalinity above 107 mg\'CA\'CO IND.3\'/L, the removal efficiency of ammonia reached values close to 100%. Regarding to COD removal, the ANF removed 40% and SAF removed 65%. In summary, in the first stage of the research the system removed 80% of COD, 89% of ammonia and 35% of nitrogen. The second stage lasted 195 days and there was a recirculation line from the SAF to the ANF. In this step, the pH was maintained close to neutral and recirculation was done in two different ways. In the first, the recirculation flow was conducted from the SAF direct to the ANF at a rate of 2.0, which resulted in 43% removal of ammonia in the ANF and 97% in the SAF. Moreover, with this form of recycling 62.6% of the total nitrogen was removed from the system. The second way was to direct part of the effluent of the SAF to the tank that contained the influent of the ANF. In this case, the recirculation rate was 1.0, and resulted in a production of 10% of ammonia in the ANF and removal of approximately 100% in the SAF. Independently of the way used for recirculation, the COD removal efficiencies was 67% and 56% in ANF and SAF, respectively. The removal of nitrate in the ANF was 93% and was independent of the form of recycling. There was a 42.5% removal of nitrogen in the system. In the second stage occurred the best removals of COD, ammonia and nitrogen. However, both the affluent and the effluent had LC50 of 0.83% to microcrustacean M. juniae. Therfore, both forms of the effluent are in disagreement with the Brazilian law Resolução CONAMA 357/05. The Aeromonas, Serratia and Pseudomonas were dominant in the SAF at the end of research.

Naphthenic acids (NAs) are carboxylic acids found in crude oil and petroleum products. The objectives of the research presented here were to: a) assess the occurrence and fate of NAs in crude oil and refinery wastewater streams; b) evaluate the biotransformation potential and inhibitory effects of NAs under nitrifying, denitrifying and methanogenic/fermentative conditions; c) investigate the factors affecting NA biotransformation under aerobic conditions and the microbes involved; and d) assess the toxicity of individual model NAs using quantitative structure-activity relationships (QSAR) and examine the effect of structure on NA biotransformation potential. NAs are ubiquitous in refinery wastewater streams and the desalter brine was found to be the main source of NAs in refinery wastewater. A commercial NA mixture was not biodegraded under nitrate-reducing or methanogenic/fermentative conditions. NAs were degraded under aerobic conditions by an NA-enriched culture; however, a residual fraction was not degraded under all conditions studied. The results indicated that NAs are not inherently recalcitrant and the residual fraction was due to the individual NA concentrations being below the minimum substrate concentrations at which they are no longer degraded. A fraction of the NA mixture was completely mineralized to carbon dioxide, with the remaining portion biotransformed to more oxidized intermediates. Overall, the results indicated that NAs were degraded under aerobic conditions; however, biological treatment of NA-bearing wastewater will not completely remove NA concentrations and thus, biological treatment must be combined with physical/chemical treatment to achieve complete NA removal.

O projeto de Estações de Tratamento de Efluentes Industriais (ETEIs) deve objetivar um desempenho médio, o qual não pode ser ultrapassado certo número de vezes durante seu tempo operacional. Este trabalho propõe a aplicação da metodologia conhecida como Coeficiente de Confiabilidade (CDC) para quantificação da confiabilidade das etapas de tratamento físico (Separação Águaóleo SAO e flotação) e biológico (lodos ativados com aeração prolongada), considerando efluente oleoso proveniente de refino de petróleo. Tal metodologia, entretanto, não possibilita a identificação das prováveis causas do baixo desempenho na tratabilidade. Por isso também é proposta a aplicação da ferramenta de gestão riscos conhecida como FMECA (Failure Modes, Effects and Criticality Analysis), que permite a quantificação das observações qualitativas de campo, tornando os valores comparáveis para definir a hierarquização dos riscos e criticidade das etapas de tratamento estudadas. A etapa biológica para o parâmetro NH3 apresentou a maior confiabilidade, ainda que a análise de risco tenha apontado esta etapa como mais crítica. Ou seja, um sistema confiável não necessariamente apresenta menor criticidade, pois uma má gestão implicará em possíveis infrações às metas pré-fixadas ou à própria legislação ambiental.

O projeto de Estações de Tratamento de Efluentes Industriais (ETEIs) deve objetivar um desempenho médio, o qual não pode ser ultrapassado certo número de vezes durante seu tempo operacional. Este trabalho propõe a aplicação da metodologia conhecida como Coeficiente de Confiabilidade (CDC) para quantificação da confiabilidade das etapas de tratamento físico (Separação Águaóleo SAO e flotação) e biológico (lodos ativados com aeração prolongada), considerando efluente oleoso proveniente de refino de petróleo. Tal metodologia, entretanto, não possibilita a identificação das prováveis causas do baixo desempenho na tratabilidade. Por isso também é proposta a aplicação da ferramenta de gestão riscos conhecida como FMECA (Failure Modes, Effects and Criticality Analysis), que permite a quantificação das observações qualitativas de campo, tornando os valores comparáveis para definir a hierarquização dos riscos e criticidade das etapas de tratamento estudadas. A etapa biológica para o parâmetro NH3 apresentou a maior confiabilidade, ainda que a análise de risco tenha apontado esta etapa como mais crítica. Ou seja, um sistema confiável não necessariamente apresenta menor criticidade, pois uma má gestão implicará em possíveis infrações às metas pré-fixadas ou à própria legislação ambiental.

Orientador: Wilson de Figueiredo Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-06T21:59:45Z (GMT). No. of bitstreams: 1 Locatelli_MarcoAntonioFernandes_M.pdf: 1462922 bytes, checksum: eff1592d31e618e67b22501e45f45f26 (MD5) Previous issue date: 2006 / Mestrado / Quimica Analitica / Mestre em Química