Made available in DSpace on 2014-12-17T15:42:07Z (GMT). No. of bitstreams: 1 LedaMOL_TESE.pdf: 3658937 bytes, checksum: 6ad7dbe6b2ec8a6f89d9264905ef89b6 (MD5) Previous issue date: 2010-12-21 / Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1? order. / Tecnologias inovadoras que usam materiais tensoativos t?m aplicabilidade em v?rios campos industriais, dentre eles petr?leo e g?s natural. Este estudo busca investigar o uso de um tensoativo, derivado de ?leo de coco (OCS - ?leo de coco saponificado), no processo de recupera??o de compostos org?nicos presentes em efluentes oleosos da ind?stria de petr?leo. Para este fim, foram realizados experimentos em uma coluna de bancada objetivando verificar a influ?ncia do tensoativo OCS na efici?ncia de remo??o de ?leo. Desta forma, foram preparadas emuls?es com quantidades fixas de ?leo (50, 100, 200 e 400 ppm), determinandose a concentra??o ?tima de tensoativo para cada uma delas. Foram, tamb?m, realizados alguns ensaios com ?gua de produ??o da ind?stria de petr?leo, visando comparar o resultado com o das emuls?es. O processo de separa??o consiste no uso de bolhas gasosas formadas quando um fluxo de g?s passa em uma coluna l?quida, com concentra??es de tensoativo, ocorrendo a coalesc?ncia das gotas de ?leo dispersas e, consequentemente, o transporte delas ao topo da coluna, formando uma nova fase oleosa cont?nua. O processo fundamenta-se na satura??o de tensoativo na interface g?s-l?quido, dependendo da concentra??o de tensoativo usada, resultando na flota??o da fase ?leo dispersa. Um filtro de prato poroso, com tamanho de poro que varia de 40 a 250 μm, foi colocado ? base da coluna para permitir uma opera??o hidrodin?mica est?vel. Durante os procedimentos experimentais, o volume operacional da fase l?quida foi mantido constante e a taxa de fluxo de ar variada em cada experimento. Os resultados experimentais do estudo hidrodin?mico demonstraram que a captura do ?leo foi influenciada pelos di?metros das bolhas e vaz?es de ar. Com o aumento da vaz?o de 300 para 900 cm3.min-1, ocorreu um aumento de remo??o da fase ?leo de 44% para 66% e a cin?tica de remo??o do ?leo foi definida como uma rea??o de 1? ordem

Made available in DSpace on 2014-12-17T15:01:13Z (GMT). No. of bitstreams: 1 PaulaKLS.pdf: 655947 bytes, checksum: 42dfa97fce97ed099a5660c9d396a0eb (MD5) Previous issue date: 2008-02-29 / In the petroleum industry, water is always present in the reservoir formation together with petroleum and natural gas and this fact provokes the production of water with petroleum, resulting in a great environmental impact. Several methods can be applied for treatment of oily waters, such as: gravitational vases, granulated media filtration systems, flotation process, centrifugation process and the use of hydrocyclones, which can also be used in a combined way. However, the flotation process has showed a great efficiency as compared with other methods, because these methods do not remove great part of the emulsified oil. In this work was investigated the use of surfactants derived from vegetable oils, OSS and OGS, as collectors, using the flotation process in a glass column with a porous plate filter in its base for the input of the gaseous steam. For this purpose, oil/water emulsions were prepared using mechanical stirring, with concentrations around 300 ppm. The air flow rate was set at 700 cm3/min and the porous plate filter used for the generation of the air bubbles has pore size varying from 16 to 40 Pm. The column operated at constant volume (1500mL). A new methodology has been developed to collect the samples, where, instead of collecting the water phase, it was collected the oil phase removed by the process in the top of the flotation column. It has been observed that it is necessary to find an optimum surfactant concentration to achieve enhanced removal efficiency. Being for OSS 1.275 mmol/L and for OGS 0.840 mmol/L, with removal efficiencies of 93% and 99%, respectively, using synthetic solutions. For the produced water, the removal in these concentrations was 75% for OSS and 65% for OGS. It is possible to remove oil from water in a flotation process using surfactants of high HLB, fact that is against the own definition of HLB (Hydrophile-Lipophile Balance). The interfacial tension is an important factor in the oil removal process using a flotation process, because it has direct interference in the coalescence of the oil drops. The spreading of the oil of the air bubble should be considered in the process, and for the optimum surfactant concentrations it reached a maximum value. The removal kinetics for the flotation process using surfactants in the optimum concentration has been adjusted according to a first order model, for synthetic water as for the produced water. / Na ind?stria petrol?fera, a ?gua est? associada ao petr?leo e ao g?s natural, formando a ?gua de produ??o e gerando um grande impacto ambiental. Existem diversos m?todos de tratamento para as ?guas oleosas, tais como: vasos gravitacionais, sistemas de filtra??o em meio granular, flota??o, centrifuga??o e utiliza??o de hidrociclones, podendo ser utilizados de forma combinada. Entretanto, a flota??o tem mostrado maior efici?ncia com rela??o aos outros m?todos, pois eles n?o conseguem remover grande parte do ?leo emulsionado. O presente trabalho estuda a utiliza??o de tensoativos de origem vegetal, OSS (?leo de Soja Saponificado) e OGS (?leo de Girassol Saponificado), como coletores, atrav?s da flota??o em uma coluna com aera??o da suspens?o atrav?s de uma placa porosa. Para este fim, foram preparadas emuls?es ?leo/?gua por agita??o mec?nica, com concentra??es m?dias de 300 ppm. A vaz?o de ar utilizada foi de 700 cm3/min e o filtro de placa porosa utilizado para a gera??o das bolhas de ar foi de porosidade de (16-40) Pm. A coluna trabalhou a um volume constante de 1500mL. Desenvolveu-se uma nova metodologia para coletar as amostras, onde, ao inv?s de coletar a ?gua, coletou-se o ?leo removido na parte superior da c?lula de flota??o. Observou-se que ? necess?rio encontrar uma concentra??o ?tima de tensoativo para que haja uma maior efici?ncia de remo??o. S?o elas 1,275 mmol/L para o OSS e 0,840 mmol/L para o OGS, com efici?ncias de remo??o de 93 % e 99 %, respectivamente, em ?guas sint?ticas. Para a ?gua de produ??o, a remo??o nestas concentra??es foi de 75% para o OSS e 65% para o OGS. ? poss?vel remover ?leo de ?gua em um processo de flota??o utilizando tensoativos de BHL alto, fato que contraria a pr?pria defini??o de BHL (Balan?o Hidrof?lico-Lipof?lico). A tens?o interfacial ? um fator importante no processo de remo??o do ?leo na flota??o, pois interfere diretamente na coalesc?ncia das gotas de ?leo. O espalhamento do ?leo da bolha de ar deve ser considerado no processo, e para as concentra??es ?timas de tensoativo atingiu um valor m?ximo. A cin?tica da remo??o se ajustou para o modelo de primeira ordem na flota??o utilizando tensoativos na concentra??o ?tima, tanto para ?gua sint?tica como para a ?gua de produ??o.

Made available in DSpace on 2014-12-17T15:01:27Z (GMT). No. of bitstreams: 1 BrunoCB_DISSERT.pdf: 4196751 bytes, checksum: 815046ef78a951368bb3e92819e92b89 (MD5) Previous issue date: 2012-05-04 / The pegmatite rocks in Rio Grande do Norte are responsible for much of the production of industrial minerals like quartz and feldspar. Quartz and feldspar are minerals from pegmatite which may occur in pockets with metric to centimetric dimensions or as millimetric to sub millimetric intergrowths. The correct physical liberation of the mineral of interest, in case of intergrowths, requires an appropriate particle size, acquired by size reduction operations. The method for treating mineral which has a high efficiency fines particles recovery is flotation. The main purpose of the present study is to evaluate the recovery of quartz and potassium feldspar using cationic diamine and quaternary ammonium salt as collectors by means of dissolved air flotation DAF. The tests were performed based on a central composite design 24, by which the influence of process variables was statistically verified: concentration of the quaternary ammonium salt and diamine collectors, pH and conditioning time. The efficiency of flotation was calculated from the removal of turbidity of the solution. Results of maximum flotation efficiency (60%) were found in the level curves, plotted in conditions of low concentrations of collectors (1,0 x 10-5 mol.L-1). These high flotation efficiencies were obtained when operating at pH 4 to 8 with conditioning time ranging from 3 to 5 minutes. Thus, the results showed that the process variables have played important roles in the dissolved air flotation process concerning the flotability of the minerals. / No Rio Grande do Norte os pegmatitos respondem por grande parte da produ??o dos minerais industriais quartzo e feldspato. O quartzo e feldspato dos pegmatitos podem ocorrer em bols?es com dimens?es centim?tricas a m?tricas ou na forma de intercrescimentos milim?tricos a submilim?tricos. No caso dos intercrescimentos, a libera??o f?sica correta do mineral de interesse envolve a adequa??o granulom?trica atrav?s de opera??es de redu??o de tamanho. O m?todo no tratamento mineral que apresenta alta efici?ncia na recupera??o de finos ? a flota??o. O presente trabalho tem como objetivo principal avaliar a recupera??o de quartzo e feldspato pot?ssico utilizando os coletores cati?nicos diamina e sal quatern?rio de am?nio no processo de flota??o por ar dissolvido FAD. Os testes foram realizados baseados em um planejamento central composto 24, atrav?s do qual verificou-se estatisticamente a influ?ncia das vari?veis de processo: concentra??o dos coletores sal quatern?rio de am?nio e diamina, pH e tempo de condicionamento. A efici?ncia de flota??o foi calculada a partir do grau de remo??o de turbidez da solu??o. Resultados de m?xima efici?ncia de flota??o (60%) foram encontrados nas curvas de n?vel, plotadas nas condi??es de baixas concentra??es dos coletores (1,0x10-5 mol.L-1). Estas altas efici?ncias de flota??o foram obtidas operando-se na faixa de pH 4 8 com tempo de condicionamento variando de 3 a 5 minutos. Sendo assim, os resultados obtidos mostraram que as vari?veis de processo desempenharam pap?is importantes no processo de flota??o por ar dissolvido em rela??o ? flotabilidade dos minerais.

Made available in DSpace on 2014-12-17T15:01:31Z (GMT). No. of bitstreams: 1 AlineVMS_DISSERT.pdf: 5061561 bytes, checksum: bab6b3b335e768bf8c3b23df4c26c8c5 (MD5) Previous issue date: 2012-12-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In recent decades, the generation of solid and liquid waste has increased substantially due to increased industrial activity that is directly linked to economic growth. For that is the most efficient process, it is inevitable generation of such wastes. In the oil industry, a major waste generated in oil exploration is produced water, which due to its complex composition and the large amount generated, has become a challenge, given the restrictions imposed by environmental laws regarding their disposal, making if necessary create alternatives for reuse or treatment in order to reduce the content of contaminants and reduce the harmful effects to the environment. This water can be present in free form or emulsified with the oil, when in the form of an emulsion of oil-water type, it is necessary to use chemicals to promote the separation and flotation is the treatment method which has proved to be more efficient, for it can remove much of the emulsified oil when compared to other methods. In this context, the object of this work was to study the individual effects and interactions of some physicochemical parameters of operations, based on previous work to a flotation cell used in the separation of synthetic emulsion oil / water in order to optimize the efficiency of the separation process through of the 24 full factorial design with center point. The response variables to evaluate the separation efficiency was the percentage of color and turbidity removal. The independent variables were: concentration of de-emulsifying, oil content in water, salinity and pH, these being fixed, minimum and maximum limits. The analysis of variance for the equation of the empirical model, was statistically significant and useful for predictive purposes the separation efficiency of the floater with R2 > 90%. The results showed that the oil content in water and the interaction between the oil content in water and salinity, showed the highest values of the estimated effects among all the factors investigated, having great and positive influence on the separation efficiency. By analyzing the response surface was determined maximum removal efficiency above 90% for both measured for turbidity as a measure of color when in a saline medium (30 g/L), the high oil concentrations (306 ppm) using low concentrations of de-emulsifying (1,1 ppm) and at pH close to neutral / Nas ?ltimas d?cadas, a gera??o de res?duos s?lidos e l?quidos tem aumentado substancialmente devido ao aumento da atividade industrial que est? diretamente ligada ao crescimento econ?mico. Por mais eficiente que seja o processo, ? inevit?vel a gera??o desses res?duos. Na ind?stria petrol?fera, um dos principais res?duos gerado na explora??o do petr?leo ? a ?gua produzida, que devido ? sua composi??o complexa e ? grande quantidade gerada, tem se tornado um desafio, diante das restri??es impostas pela legisla??o ambiental quanto ao seu descarte, fazendo-se necess?rio criar alternativas de reuso ou tratamento com a finalidade de reduzir o teor de contaminantes e diminuir os efeitos nocivos ao meio ambiente. Essa ?gua pode estar presente sob a forma livre ou emulsionada com o ?leo, quando na forma de emuls?o do tipo ?leo/?gua, faz-se necess?rio ? utiliza??o de subst?ncias qu?micas para promover a separa??o, sendo a flota??o o m?todo de tratamento que vem se mostrando mais eficiente, pois consegue remover grande parte do ?leo emulsionado quando comparada a outros m?todos. Nesse contexto, o objetivo deste trabalho foi estudar os efeitos individuais e de intera??es de alguns par?metros f?sico-qu?micos operacionais, baseado em trabalhos anteriores, para uma c?lula de flota??o utilizada na separa??o de emuls?o sint?tica ?leo/?gua, visando otimizar a efici?ncia do processo de separa??o atrav?s um planejamento experimental do tipo fatorial completo 24 com ponto central. As vari?veis de resposta para avaliar a efici?ncia da separa??o foram percentagem de remo??o de cor e turbidez. As vari?veis independentes estudadas foram: concentra??o do desemulsificante, teor de ?leo em ?gua, salinidade e pH, sendo fixadas a estas, limites m?nimos e m?ximos. A an?lise da vari?ncia para a equa??o do modelo emp?rico mostrou-se estatisticamente significante e ?til para fins preditivos da efici?ncia de separa??o do flotador com R2 > 90%. Os resultados mostraram que o teor de ?leo em ?gua e a intera??o entre o teor de ?leo em ?gua e a salinidade, apresentaram os maiores valores dos efeitos estimados dentre o conjunto dos fatores investigados, tendo grande e positiva influ?ncia na efici?ncia de separa??o. Atrav?s da an?lise da superf?cie de resposta, foi determinada uma efici?ncia m?xima de remo??o acima de 90% tanto para medida de turbidez quanto para medida de cor quando em meio salino (30 g/L), a altas concentra??es de ?leo (306 ppm), utilizando concentra??es baixas do desemulsificante (1,1 ppm) e com pH pr?ximo do neutro

Made available in DSpace on 2014-12-17T15:03:31Z (GMT). No. of bitstreams: 1 LorenaAAS_DISSERT.pdf: 1823749 bytes, checksum: 12d88ee29bda4ea738e34260da21491c (MD5) Previous issue date: 2013-09-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The struvite precipitation in wastewater treatments plants offer advantages to obtaining a economically viable product, containing phosphorus, nitrogen and magnesium, in a bioavailable conditions to plants. The precipitation process requires ideal conditions, but all of these aspects are difficult to obtain and may result in resistance to collect crystals during the sedimentation process. Therefore, instead find the best conditions for precipitation, we propose the dissolved air flotation as another method to retrieve the crystals. The application of dissolved air flotation method to promote separation of struvite crystals from sewage supernatant, was evaluated in a precipitation-flotation reactor (flotatest) and were compared with the precipitation-sedimentation assays (jar test). Finally, were observed that the dissolved air flotation process was as feasible as sedimentation to promote struvite crystals separation, and the pH are the most influencer factor for an efficient separation / A precipita??o de estruvita em Esta??es de Tratamento de Esgoto oferece como vantagem a obten??o de um produto economicamente vi?vel, com f?sforo, nitrog?nio e magn?sio em sua composi??o e biologicamente dispon?vel para as plantas. Este processo necessita de condi??es ideais para que ocorra a precipita??o, por?m a dificuldade de atingir tais condi??es pode resultar em resist?ncia na coleta de cristais durante o processo de sedimenta??o. Assim, em vez de buscar as melhores condi??es de precipita??o, que em muitos casos n?o podem ser atingidas, propomos utilizar a flota??o por ar dissolvido (FAD) como uma alternativa ? sedimenta??o de part?culas. A avalia??o da aplicabilidade do processo de Flota??o por Ar Dissolvido (FAD) na separa??o de cristais de estruvita em percolado de lodo foi realizada em reator de precipita??o-flota??o (flotateste) e comparada com ensaios de precipita??o-sedimenta??o (jar teste). Por fim, foi observado que a flota??o por ar dissolvido ? vi?vel na separa??o de cristais de estruvita tanto quanto a sedimenta??o, sendo o pH o fator que exerceu maior influ?ncia sobre a efici?ncia de separa??o

Made available in DSpace on 2014-12-17T15:03:32Z (GMT). No. of bitstreams: 1 CeresVCD_DISSERT.pdf: 2077286 bytes, checksum: e92bca4faf414c0d0c184dc10f694c85 (MD5) Previous issue date: 2013-05-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Experience in the use of stabilization ponds shows that this is a system with low cost, easy operation and maintenance and suitable for tropical countries. One of its disadvantages is due to high concentrations of suspended solids, mainly due to algal biomass in the effluents. Accordingly, the dissolved air flotation has been shown to be an efficient post-treatment technology. However, the efficiency of this process is related to coagulation and flocculation steps, as well as the adjustment of the involved variables in the process. The objective of this work was to evaluate the algae removal efficiency from wastewater stabilization ponds and the influence of the factors involved in the process using dissolved air flotation. For this, we used primary facultative and maturation effluents of ETE Ponta Negra in Natal. We did tests of coagulation, flocculation and flotation with the samples, using the equipment flotatest. In this process were tested coagulants aluminum sulfate and ferric chloride, and varied the factors pH, coagulant concentration, polymer concentration and rate of recirculation. At the end of the experiments were analyzed turbidity, suspended solids, color, COD and chlorophyll "a". These results were submitted to descriptive statistics to verify the efficiency of the process in general, and regression analysis to identify models that describe the process and demonstrate the factors that have greater influence on flotation. After step methodology, high values were found removal efficiency of suspended solids, reaching values greater than 90% in the best cases. It was concluded that flotation is more efficient in the facultative pond effluent using ferric chloride, and the variability of algae may negatively influence the process. Regression analyzes showed that pH is the most influential variable in the coagulation-flocculation-flotation, and its optimal value among the tested is 5.5 for both coagulants / A experi?ncia no uso de lagoas de estabiliza??o mostra que esse ? um sistema que apresenta baixo custo, f?cil opera??o e manuten??o e adequado a pa?ses tropicais. Apesar disso, uma de suas desvantagens est? relacionada ?s elevadas concentra??es de s?lidos suspensos, devido principalmente ? biomassa das algas nos efluentes. Com o objetivo de remover tais algas, a flota??o por ar dissolvido tem se mostrado como uma eficiente t?cnica de p?s-tratamento. No entanto, a efici?ncia desse processo est? relacionada ?s etapas de coagula??o e flocula??o pr?vias, bem como ao ajuste das vari?veis envolvidas no processo. Nesse contexto, o presente trabalho objetivou avaliar a efici?ncia de remo??o de algas de efluente de lagoas de estabiliza??o bem como a influ?ncia dos fatores envolvidos utilizando o processo de flota??o por ar dissolvido. Para isso, foi utilizado efluente das lagoas facultativa prim?ria e de matura??o da ETE Ponta Negra, em Natal. As amostras coletadas foram submetidas a ensaios de coagula??o, flocula??o e flota??o com vistas ? remo??o de s?lidos suspensos, utilizando-se o equipamento flotateste. Nesse processo foram testados os coagulantes sulfato de alum?nio e cloreto f?rrico, e variados os fatores pH, concentra??o de coagulante, concentra??o de pol?mero e taxa de recircula??o da ?gua saturada. Ao fim dos experimentos, foram analisados turbidez, s?lidos suspensos, cor, DQO e clorofila a . Esses resultados foram submetidos a estat?stica descritiva para verifica??o da efici?ncia do processo em geral, e an?lise de regress?o para identificar modelos que descrevam o processo e demonstrem os fatores que apresentam maior influ?ncia na flota??o. Ap?s o desenvolvimento dos ensaios, foram encontradas altas efici?ncias de remo??o de s?lidos suspensos, chegando a valores superiores a 90% nos melhores casos. Concluiu-se que a flota??o ? mais eficiente no efluente de lagoa facultativa utilizando-se o cloreto f?rrico, e que a variabilidade de algas pode influenciar negativamente no processo. As an?lises de regress?o demonstraram que o pH ? a vari?vel de maior influ?ncia na coagula??o-flocula??o-flota??o, sendo que o seu valor ?timo dentre os testados foi 5,5 para os dois coagulantes

Made available in DSpace on 2014-12-17T14:09:19Z (GMT). No. of bitstreams: 1 JonatasALJ_TESE.pdf: 9049452 bytes, checksum: dd9b668c8bc7791108be8a6bbc44e152 (MD5) Previous issue date: 2014-04-28 / A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity / Um prot?tipo vibr?til autoflotador de acionamento eletromec?nico para tratamento de ?gua de produ??o de petr?leo e emuls?o cong?nere ? apresentado e avaliado. A produ??o de petr?leo para refinamento e obten??o de derivados ? realizada sob modalidades tecnicamente referidas como on-shore e off-shore, isto ?, no continente e no mar. No Brasil 80% da produ??o petrol?-fera ? feita no mar e ?rea de implanta??o e escala de custo s?o preocupantes. Associa-se ?gua oleosa de produ??o, efluente abundante em larga escala, carreadora de 95% do potencial polu-idor da atividade cujo destino final ? o meio ambiente mar?timo ou terrestre. Embora diversi-ficado conjunto de t?cnicas e sistemas de tratamento d ?gua encontram-se em uso ou pesqui-sa, prop?e-se um sistema inovador que opera de forma sustent?vel sem aditivos qu?micos, pa-ra o bem do ecossistema. Utilizou-se labirinto adsorvente, em espirais met?licos, e escala la-boratorial de fluxo. Patentes de equipamento e processo s?o reivindicadas. Realizaram-se tra-tamentos em vaz?es e faixas de frequ?ncia distintas, monitoradas com sistemas de controle, uns constru?dos, outros aquistados para tal. Medi??es do teor de ?leo e graxa (TOG) do eflu-ente tratado mantiveram-se dentro do intervalo de enquadramento legal nas condi??es de en-saio. Pesaram-se os adsorventes antes e ap?s o tratamento para obten??o da impregna??o de ?leo, meta de desempenho da a??o vibrat?ria e tratamento como um todo. Tecnologias atuais de tratamento s?o referenciadas para compara??o de desempenho, qualitativa e quantitativa-mente. Confrontou-se consumo energ?tico operando-se em vibra??o, com e sem flota??o con-vencional, e com autoflota??o. Vislumbram-se boas perspectivas de rendimento do sistema proposto, sobretudo, na redu??o do tempo de resid?ncia por a??o de capilaridade. Criou-se o par?metro adimensional de impregna??o e se lhe confrontou com consagrados par?metros a-dimensionais, na vers?o vibracional, como n?mero de Weber e n?mero de Froud quadr?tico, referido como criticalidade vibr?til. Resultados sugerem limites ? intensidade vibrat?ria

Made available in DSpace on 2014-12-17T15:01:47Z (GMT). No. of bitstreams: 1 PatriciaGSL.pdf: 4325839 bytes, checksum: ed5182708cd9548f2c8eca5937447cd6 (MD5) Previous issue date: 2008-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work aims to investigate the process of Dissolved air Flotation (DAF) for clarifying water samples with low turbidity using aluminum sulphate and Moringa oleifera seeds as coagulants. The experimental procedure was carried out in a bench scale flotation unit. The influences on the pre-treatment conditions (coagulant dosage and flocculation time) and flotation parameters (superficial application rate and recirculation rate) were evaluated considering the efficiency of the process. The efficiency was evaluated by determining the turbidity of the untreated and treated water samples. The results obtained showed that turbidity reduction can be obtained very efficiently by using DAF and the latter coagulant in low turbidity water. Using aluminum sulphate in pH?s 5.0 and 6.0 better efficiencies were obtained with low concentrations (15 mg/L), achieving values of 92% of turbidity reduction. In the case of use of Moringa oleifera better efficiencies of reduction of turbidity were reported when using a concentration of 50 mg/L in all range of pH?s, achieving 86% of reduction. The zeta potential was also determined, in an attempt to aid comprehension of the coagulation mechanisms involved. The coagulation mechanisms with Moringa oleifera seeds were shown to be adsorption and charge neutralization, as well as adsorption and bridging. Concerning aluminum sulphate, the predominant mechanisms are adsorption and charge neutralization and enmeshment in a precipitate. The results indicate that for low turbidity water, Moringa oleifera seeds could potentially be a viable substitute for aluminum sulphate / O presente trabalho tem como objetivo investigar o processo da flota??o por ar dissolvido sob press?o - FAD para clarifica??o de ?guas com baixa turbidez utilizando sulfato de alum?nio e sementes de Moringa oleifera como coagulantes. O procedimento experimental foi realizado em uma unidade de flota??o em escala de bancada. Foram avaliadas as influ?ncias das condi??es do pr?-tratamento (dosagem de coagulante e tempo de flocula??o) e par?metros de processo da flota??o (taxa de aplica??o superficial e taxa de recircula??o) na efici?ncia do processo. A efici?ncia foi avaliada pela determina??o de turbidez nas amostras de ?gua bruta e tratada. Os resultados obtidos mostraram que elevadas efici?ncias de redu??o da turbidez podem ser conseguidas com o uso da FAD em ?guas com baixa turbidez utilizando estes coagulantes. Para o sulfato de alum?nio, nos pHs 5,0 e 6,0 as melhores efici?ncias foram alcan?adas com baixas dosagens (15 mg/L), alcan?ando valores de at? 92% de redu??o. Para a Moringa oleifera, as melhores efici?ncias de redu??o de turbidez foram ? dosagem aproximada de 50 mg/L para todos os pHs, alcan?ando valores de 86% de redu??o. Determinou-se tamb?m o potencial zeta, com o objetivo de auxiliar na compreens?o dos mecanismos envolvidos na coagula??o. Os mecanismos de coagula??o com sementes de Moringa oleifera indicam ser adsor??o e neutraliza??o de cargas e adsor??o e forma??o de pontes. No que diz respeito ao sulfato de alum?nio os mecanismos predominantes s?o adsor??o e neutraliza??o de cargas e varredura. Os resultados indicam que para ?guas de baixa turbidez, as sementes de Moringa oleifera podem ser um substituto potencialmente vi?vel em rela??o ao sulfato de alum?nio