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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tratamento de ?gua produzida utilizando a t?cnica combinada flocula??o/flota??o por ar dissolvido com mistura de polieletr?litos e moringa ole?fera / Treatment of produced water using combined technique flocculation/dissolved air flotation with the mix of polyelectrolyte and moringa ole?fera

Freitas, J?ssica Isabelle de Souza 29 July 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-02T12:10:53Z No. of bitstreams: 1 JessicaIsabelleDeSouzaFreitas_DISSERT.pdf: 2915021 bytes, checksum: d55fbdf3b47d9ac4f3a9ba65f22a6c3f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-07T16:31:25Z (GMT) No. of bitstreams: 1 JessicaIsabelleDeSouzaFreitas_DISSERT.pdf: 2915021 bytes, checksum: d55fbdf3b47d9ac4f3a9ba65f22a6c3f (MD5) / Made available in DSpace on 2017-02-07T16:31:25Z (GMT). No. of bitstreams: 1 JessicaIsabelleDeSouzaFreitas_DISSERT.pdf: 2915021 bytes, checksum: d55fbdf3b47d9ac4f3a9ba65f22a6c3f (MD5) Previous issue date: 2016-07-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A ind?stria de petr?leo ? um dos setores com maior potencial de degrada??o ambiental, sendo a ?gua produzida o res?duo mais relevante. A complexa composi??o qu?mica e o elevado volume gerado deste efluente exigem um rigoroso controle e gerenciamento. Assim, antes de ser descartada, reinjetada em po?os ou para outra finalidade esta ?gua deve ser tratada de acordo com a legisla??o ambiental vigente. No que se refere ao tratamento de ?gua produzida para remo??o do teor de ?leos e graxas, a t?cnica combinada flocula??o/flota??o por ar dissolvido vem sendo bastante estudada. Na etapa de flocula??o vem sendo utilizado floculantes qu?micos convencionais de elevado custo e n?o-biodegrad?veis. Nesse contexto, avaliou-se a efici?ncia de remo??o do teor de ?leos e graxas da ?gua produzida atrav?s da t?cnica combinada flocula??o/flota??o por ar dissolvido utilizando a mistura de floculantes natural de Moringa ole?fera e dois floculantes comerciais ?C? e ?D? (j? utilizados na ind?stria), objetivando deixar a ?gua produzida nas condi??es de descarte. Os ensaios foram realizados segundo planejamento experimental para avalia??o estat?stica da influ?ncia da concentra??o total de floculante, tempo de mistura lenta e tempo de flota??o na efici?ncia de remo??o do teor de ?leos e graxas. Al?m disso, para cada mistura e suas respectivas propor??es estudadas, obtiveram-se modelos matem?ticos. O tratamento do efluente utilizando a mistura do floculante Moringa ole?fera e floculante comercial ?D?, com propor??o de mistura em base volum?trica 50:50%, atendeu os requisitos ambientais em todas as condi??es avaliadas; enquanto, nas mesmas condi??es, n?o foi poss?vel utilizando a mistura do floculante Moringa ole?fera e floculante comercial ?C?. Tamb?m verificou-se a efici?ncia de remo??o de ?leos e graxas com mistura do floculante Moringa ole?fera e floculante comercial ?D? com propor??o de mistura em base volum?trica 70:30% (respectivamente) sendo esta condi??o de interesse ambiental, uma vez que foi poss?vel atender os requisitos ambientais para descarte da ?gua produzida. Todas as misturas do floculante de Moringa ole?fera e floculantes comerciais ?C? e ?D? estudadas mostraram-se eficazes na adequa??o da ?gua produzida para descarte. Finalmente, avaliou-se o efeito potencializador da Moringa ole?fera sobre o floculante comercial ?D? na remo??o do teor de ?leos e graxas da ?gua produzida. / The Oil Industry is one of the sectors with greatest potential for environmental degradation and the produced water is the largest waste stream generated in this industry. The complex chemical composition and the high volume generated of this effluent hold a strict control and management. In accordance with current environmental legislation the water should be treated before final disposal, reuse or recycle including underground injected vapor to increase oil production. In view of the treatment of produced water for oil and grease content removal, the combined technique flocculation/dissolved air flotation has been extensively studied. In the flocculation step has been used high cost flocculants of chemical industry which are non-biodegradable. In this context it was evaluated the removal efficiency of oil and grease content from produced water by the combined technique flocculation/dissolved air flotation using Moringa Ole?iferaM.O) a natural flocculant blended with two commercial flocculants ?C? and ?D? (currently used in the oil industry), aiming to let the water produced in the disposal conditions. The experiments were conducted by means of statistical experimental design evaluating the influence of the total concentration of flocculants, slow mixing time and flotation time over the efficiency of oil and grease content removal. Moreover, for each mixture and their respective ratios studied, were obtained mathematical models. The effluent treatment using the mixture of Moringa ole?fera and commercial ?D? flocculants with mixing ratio of 50:50 (%, volume basis) achieved the environmental requirements in all conditions evaluated, while, under the same conditions it wasn?t possible using the mixture of Moringa Ole?fera and commercial ?C? flocculant. The oil and grease removal content efficiency using a mixing ratio of 70:30 (%, volume basis of M. O and commercial flocculant, respectively) showed to be an interesting condition to reach the environmental requirements for produced water disposal once all mixtures of Moringa Ole?fera and commercial flocculants ?C? and ?D? achieved satisfactory experimental results for produced water disposal. Finally, we evaluated the effect of improvement of Moringa ole?fera into commercial flocculant ?D? on oil and grease removal content efficiency.
2

Flota??o por ar dissolvido como p?s-tratamento de efluentes de lagoas de estabiliza??o

Brito, Andr? C?mara de 08 July 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-12T14:42:23Z No. of bitstreams: 1 AndreCamaraDeBrito_DISSERT.pdf: 1740307 bytes, checksum: 2791cedd5bfccff8d9fbd2dc3410084e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-18T14:38:30Z (GMT) No. of bitstreams: 1 AndreCamaraDeBrito_DISSERT.pdf: 1740307 bytes, checksum: 2791cedd5bfccff8d9fbd2dc3410084e (MD5) / Made available in DSpace on 2017-01-18T14:38:30Z (GMT). No. of bitstreams: 1 AndreCamaraDeBrito_DISSERT.pdf: 1740307 bytes, checksum: 2791cedd5bfccff8d9fbd2dc3410084e (MD5) Previous issue date: 2016-07-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Para tratamento de esgotos dom?sticos lagoas de estabiliza??o possuem importantes vantagens, como elevada efici?ncia na remo??o de mat?ria org?nica e organismos patog?nicos, n?o utiliza??o de energia el?trica e facilidade operacional, principalmente em regi?es de clima tropical. Por outro lado, uma de suas desvantagens ? a elevada concentra??o de s?lidos suspensos, principalmente devido a biomassa algal. O objetivo desta pesquisa foi avaliar a efici?ncia de remo??o da flota??o por ar dissolvido (FAD) no p?s-tratamento de efluentes de lagoas de estabiliza??o. Para os ensaios com a FAD (coagula??o-flocula??o-flota??o) foi utilizado um flotateste de bancada. Foi planejado um delineamento experimental tipo fatorial aleat?rio, utilizando o crit?rio ka-1, em que k ? o n?mero de n?veis (k=3: menor, central, maior) e a ? o n?mero de fatores (a=4: dose de coagulante, taxa de recircula??o de ?gua saturada, pH e tempo de flocula??o), com ensaios realizados em triplicata, para os coagulantes policloreto de alum?nio e cloreto f?rrico em efluente de lagoas de facultativa prim?ria e lagoa de matura??o. As amostras do efluente da lagoa facultativa e efluente final da ETE Ponta Negra (Natal) foram coletadas semanalmente, no per?odo da manh?. As seguintes vari?veis foram avaliadas nos efluentes brutos e ap?s os ensaios com FAD: turbidez, s?lidos suspensos totais, cor aparente, DQO, clorofila ?a?, fosforo total, ortofosfato sol?vel e nitrog?nio amoniacal e org?nico. A vari?vel operacional com maior influ?ncia na remo??o as vari?veis avaliadas foi a dose de coagulante para o coagulante PAC e para o coagulante cloreto f?rrico a maior influ?ncia na remo??o das vari?veis foi o pH seguido da dosagem de coagulante. A partir da dosagem otimizada as remo??es nos par?metros analisados atingiram valores entre 66% e 97%. O p?s-tratamento na lagoa facultativa obteve o maior percentual de remo??o nas vari?veis analisadas para os dois coagulantes, assim como o cloreto f?rrico obtive maiores percentuais de remo??o em todas as situa??es. / For treatment of wastewater stabilization ponds have important advantages, such as high efficiency in removing organic matter and pathogens, non-use of electricity and operational ease, especially in tropical regions. On the other hand, one of its disadvantages is the high concentration of suspended solids, mostly due to algal biomass. The objective of this research was to evaluate the removal efficiency flotation by dissolved air (FAD) in the post-treatment stabilization ponds effluent. For tests with the FAD (coagulation-flocculation-flotation) we used a bench flotateste. a random factorial experimental design was planned using the ka-1 criterion, where k is the number of levels (k = 3: low, middle, major) and a is the number of factors (a = 4: coagulant dose saturated, water recirculation rate, pH and flocculation time) with assays performed in triplicate for the coagulant polyaluminium chloride, ferric chloride effluent primary facultative lagoons and maturation pond. Samples of the effluent from the facultative pond and final effluent from the WWTP Ponta Negra (Natal) were collected weekly in the morning. The following variables were evaluated in the raw wastewater and after the tests with FAD: turbidity, total suspended solids, apparent color, COD, chlorophyll "a", total phosphorus, orthophosphate soluble and ammonia and organic nitrogen. The operational variable with higher influence on the removal variables was evaluated coagulant dose for the PAC coagulant and the coagulant ferric chloride to remove the greatest influence variable was the pH followed by coagulant dosage. From the optimized dosage removals in the analyzed parameters reached values between 66% and 97%. The post-treatment in the facultative pond had the highest percentage removal in variables for the two coagulants, and ferric chloride got higher removal percentages in all situations.
3

Unraveling knowledge gaps about cyanobacterial blooms and proposing an alternative for lake restoration

Medeiros, Leonardo Rafael 28 December 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:36:28Z No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T20:04:47Z (GMT) No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) / Made available in DSpace on 2017-03-16T20:04:47Z (GMT). No. of bitstreams: 1 LeonardoRafaelMedeiros_DISSERT.pdf: 2075288 bytes, checksum: 2bc53649b8f302a0ac6c99aad966ca6a (MD5) Previous issue date: 2016-12-28 / A eutrofiza??o artificial tem sido considerada um problema de grande preocupa??o nos ecossistemas aqu?ticos em todo o mundo. Desde 1960, os avan?os cient?ficos t?m sido feitos a fim de desenvolver t?cnicas que atenuem os efeitos da eutrofiza??o. V?rios procedimentos f?sicos, qu?micos e biol?gicos podem ser usados e combinados para recuperar lagos de flora??es de cianobact?rias, como a aplica??o de um floculante combinado com argila natural ou modificada. No entanto, a efic?cia dos solos de regi?es ?ridas na mitiga??o de flora??es ? desconhecida para lagos artificiais brasileiros. Neste artigo, apresentamos uma an?lise bibliom?trica da evolu??o de publica??es sobre flora??es de cianobact?rias e identificamos registros que diretamente objetivam superar a ocorr?ncia dessas flora??es. Al?m disso, avaliamos, por meio de experimentos laboratoriais, o efeito do uso combinado do floculante policloreto de alum?nio (PAC) e um solo local do entorno do lago (LS), como lastro, no controle de flora??es de cianobact?rias em um lago raso da regi?o semi?rida do Brasil. A pesquisa bibliom?trica foi conduzida com o banco de dados "Web of Science" atrav?s da fun??o de busca ?TS = ((cyanobacteri* or blue green algae or cyanoprokariote or cyanophyceae) and (mass accumulation or bloom or domina*))?, de 1969 a junho de 2016. Realizamos uma an?lise de freq??ncia de palavras-chave e quantificamos o n?mero de registros com uma abordagem de restaura??o. Al?m disso, foram realizadas tr?s s?ries de experimentos em tr?s momentos com flora??es diferentes em composi??o e biomassa no Reservat?rio Armando Ribeiro Gon?alves. Nossa pesquisa revelou que os estudos sobre as flora??es de cianobact?rias aumentaram exponencialmente e seu impacto quantitativo nas ci?ncias aqu?ticas aumentou significativamente ao longo dos anos (F = 97,52; p <0,0001). Os EUA se destacam como a na??o mais produtiva, seguida pela China e pa?ses europeus. A China aumentou impressionantemente sua contribui??o para essa ?rea, superando os EUA nos ?ltimos cinco anos. Estudos sobre Microcystis e toxinas, tais como microcistinas, s?o tend?ncias de investiga??o, devido a sua omnipresen?a e suas consequ?ncias negativas hist?ricas. Tamb?m enfatizamos a necessidade de mais estudos com o objetivo de desenvolver t?cnicas para resolver e/ou mitigar a quest?o das flora??es. Em vista disso, nossos experimentos revelaram que o uso de PAC e LS teve um efeito not?vel na biomassa de cianobact?rias da coluna de ?gua em todas as amostragens, reduzindo at? 90% a concentra??o de clorofila-a. O uso de LS sozinho foi ineficiente para remover a biomassa de algas azuis. Em duas amostragens, a combina??o de floculante e lastro apresentou a mesma efic?cia que o uso apenas de PAC. Mesmo assim, o uso de LS ? importante para garantir a sedimenta??o. Combinado com PAC, o LS foi um lastro t?o eficiente em remover cianobact?rias quanto uma argila modificada comercialmente dispon?vel (Phoslock?). Embora LS in natura tenha liberado quantidades consider?veis de f?sforo e n?o apresentou capacidade de adsor??o de P, tal argila conseguiu adsorver quantidades moderadas de f?sforo dissolvido ap?s a mat?ria org?nica ter sido removida por muflagem. Este estudo mostra que LS ? uma alternativa economicamente vi?vel e sustent?vel para ser utilizada como a??o de manejo em reservat?rios apresentando flora??es na regi?o semi?rida do Brasil. / Artificial eutrophication has been considered a problem of major concern in aquatic ecosystems around the world. Since 1960, scientific advances have been made in order to develop techniques that mitigate the effects of eutrophication. Several physical, chemical and biological procedures can be used and combined to recover lakes from cyanobacterial blooms, such as the application of a flocculant combined with natural or modified clay. However, the efficacy of local dryland soils in mitigating blooms is unknown for Brazilian manmade lakes. In this paper, we present a bibliometric analysis of the evolution of publications about cyanobacterial blooms and identify records that directly aim to overcome the occurrence of these blooms. Also, we evaluate, through laboratory experiments, the effect of the combined use of flocculent polyaluminum chloride (PAC) and a local soil from the lake catchment (LS), as ballast, in controlling cyanobacterial bloom in a shallow lake of the semiarid region of Brazil. The bibliometric research was conducted with the ?Web of Science? database through the search function ?TS = ((cyanobacteri* or blue green algae or cyanoprokariote or cyanophyceae) and (mass accumulation or bloom or domina*))?, from 1969 to June 2016. We performed a keyword frequency analysis and quantified the number of records with a restoration approach. Besides, three sets of experiments were performed in three sampling occasions with different bloom compositions and biomass in Armando Ribeiro Gon?alves Reservoir. Our study revealed that studies about cyanobacterial blooms increased exponentially and their quantitative impact on the aquatic sciences increased significantly along the years (F = 97.52; p < 0.0001). The USA stands out as the most productive nation, followed by China and European countries. China has impressively increased its contribution to this area, surpassing the USA in the last five years. Studies about Microcystis and toxins, such as microcystins, are trends in research, due to their ubiquitousness and historical negative consequences. We also emphasize the need for more studies aiming at developing techniques to solve and/or mitigate the issue of blooms. In view of this, our experiments revealed that the use of PAC and LS had a remarkable effect on cyanobacterial biomass in the water column in all samplings, reducing up to 90% top chlorophyll-a concentration. The use of LS alone was inefficient to settle blue-green-algal biomass. In two samplings, the combination of flocculant and ballast exhibited the same efficacy as the use of solely PAC. Even so, the use of LS is important to ensure sedimentation. Combined with PAC, LS was as efficient a ballast to remove cyanobacteria as a commercially available modified clay (Phoslock?). Althugh LS in natura released considerable amounts of phosphorus and did not present P adsorption capacity, it managed to adsorb some dissolved phosphorus after organic matter was removed through muffling. This study shows that LS is a cheap, feasible and environment-friendly alternative to be used as a management action in reservoirs undergoing blooms in the semiarid region of Brazil.

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