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Organic/inorganic materials have a high potential to enable major advances in membrane performance. It has previously been impossible to develop polymeric systems with adequate transport properties for xylene purification. Zeolite membranes have been created with the appropriate selectivities; however low productivity, low mechanical durability, and high capital costs have kept these materials from being utilized. So-called mixed matrix hybrid organic/inorganic membranes combine the mechanical durability and cost effectiveness of polymeric membranes with the enhanced performance of zeolitic structures. This project will focus on investigating polymeric and molecular sieve materials for mixed matrix membrane use in xylene isomer separation as a model system. Torlon polyamide-imide has unique properties that should be potentially useful in a mixed matrix composite. Silicalite will be investigated as the dispersed phased given its proven applicability with xylene isomers. The overarching goal is to establish an approach for creation of mixed matrix materials that can be broadly applied to challenging organic separations. This project has three specific goals: (1) characterization of Torlons inherent properties, processing ability, and important transport potential, (2) characterization of zeolite matching properties and the effect of interfacial engineering on these properties, and (3) development of appropriate approaches to combine the sieve and polymer to obtain a hybrid material with properties that match theoretically predicted separation property enhancements relative to the neat polymer. High temperature pervaporation will be used to evaluate material transport properties, as this experimental setup closely mimics the high activity vapor streams found in many industrial xylene processes. The results of this research will be used to develop a protocol for development of future mixed matrix membranes that may be applied to a variety of organic liquid systems.

This laboratory column (125 cm high, 15 cm diameter) research investigated solids and P removal from liquid swine manure amended with calcium carbonate, magnesium sulphate, alum and polyacrylamide (PAM). Results showed that PAM was the most effective amendment for enhancing solids removal from manure containing 1% initial total solids (TS). The effectiveness of PAM was lower at 5% and 8% than at 1% due to resuspension of solids occurring at settling times beyond 4 h. After 24 h of settling, P removal from non-amended manure was comparable to that in amended manure and decreased with TS concentration for all amendments except alum, which was equally effective at all TS concentrations. These results indicate that, for manure containing 1% TS, P can be adequately removed by gravity separation without addition of chemical amendments while alum is a more effective amendment for removing P from manure containing higher (5% and 8%) TS.

This laboratory column (125 cm high, 15 cm diameter) research investigated solids and P removal from liquid swine manure amended with calcium carbonate, magnesium sulphate, alum and polyacrylamide (PAM). Results showed that PAM was the most effective amendment for enhancing solids removal from manure containing 1% initial total solids (TS). The effectiveness of PAM was lower at 5% and 8% than at 1% due to resuspension of solids occurring at settling times beyond 4 h. After 24 h of settling, P removal from non-amended manure was comparable to that in amended manure and decreased with TS concentration for all amendments except alum, which was equally effective at all TS concentrations. These results indicate that, for manure containing 1% TS, P can be adequately removed by gravity separation without addition of chemical amendments while alum is a more effective amendment for removing P from manure containing higher (5% and 8%) TS.

Orientador: José Renato Zanini / Banca: Antônio Carlos Barreto / Banca: Tarlei Arriel Botrel / Banca: Luiz Carlos Pavani / Banca: Antônio Sergio Ferraudo / Resumo: Os hidrociclones são equipamentos amplamente utilizados pela indústria em processos envolvendo separação sólido-líquido, porém, ainda, pouco divulgados na agricultura irrigada brasileira. Buscou-se neste trabalho determinar a perda de carga e avaliar o desempenho de um hidrociclone de geometria "Rietema" como pré-filtro de partículas sólidas. Os testes foram realizados no Centro Federal de Educação Tecnológica de Uberaba - MG - Brasil utilizando um hidrociclone de geometria "Rietema". Este equipamento possui um diâmetro de 19,20 cm na parte cilíndrica e opera com vazões variando entre 10 m3 h-1 e 27 m3 h-1. Os materiais particulados usados em suspensão foram: solo franco-argiloso e areia de rio. Os resultados mostraram que a perda de carga máxima média foi de 52 kPa e 47 kPa para as suspensões aquosas de areia e solo, respectivamente. Seu melhor desempenho ocorreu operando com suspensão aquosa de areia, apresentando eficiência total de 92,31% para a vazão de 26,97 m3 h-1. Dentre as conclusões pode-se inferir que o equipamento avaliado é eficiente para remoção de partículas de areia, podendo ser utilizado como pré-filtro em sistemas de irrigação. / Abstract: The hydrocyclones are equipments widely used by industry in cases involving solid-liquid separation, but still, little reported in brazilian irrigated agriculture. The proposal of this research was to determining the head loss and evaluate the performance of a hydrocyclone of geometry "Rietema" as a pre-filter of solid particles. The tests were performed in the Centro Federal de Educação Tenológica de Uberaba - MG - Brazil using a hydrocyclone of Rietema geometry. This equipment has a diameter of 19.20 cm at the cylindrical part and operates with flows ranging between 10 m3 h-1 and 27 m3 h-1. The materials used in particulate suspension were: clay loam soil and sand from river. The results showed that the average maximum head loss was 52 kPa and 47 kPa of aqueous suspensions of sand and soil, respectively. Its best performance occurred operating with slurry of sand, presenting total efficiency of 92.31% for flow rate of 26.97 m3 h-1. Among the conclusions can be inferred that the equipment is judged effective at removing particles of sand and can be used as pre-filter in irrigation systems. / Doutor

A fundamental challenge for liquid-liquid separation techniques such as countercurrent chromatography (CCC)and centrifugal partition chromatography (CPC), is the swift, efficient selection of the two phase solvent system containing more than two solvents, for the purification of pharmaceuticals and other molecules. A purely computational model that could predict the optimal solvent systems for separation using just molecular structure would be ideal for this task. The experimental value being predicted is the partition coefficient (Kd), which is the concentration of the compound in one phase divided by the concentration in the other. Using this approach, Quantitative Structure Activity Relationship (QSAR) models have been developed to predict the partitioning of compounds in two phase systems from the molecular structure of the compound using molecular descriptors. A Kd value in the range of 0.5 to 2 will give optimal separation. Molecular descriptors are varied, examples include logP values, hydrogen bond donor values and the number of oxygen atoms. This work describes how the QSAR models were developed and tested. A dataset of experimental logKd values for 54 compounds in six different combinations of four solvents (heptane, ethyl acetate, methanol and water) was used to train the QSAR models. A set of 196 possible molecular descriptors was generated for the 54 compounds and a partial least squares regression was used to identify which of these was significant in the relationship between logKd and molecular structure. The resulting models were used to predict the logKd values of four test compounds that had not been used to build the QSAR models. When these predictions were compared to the experimental logKd values, the root mean squared error for four of the six models was less than 0.5 and less than 0.7 for the remaining two. These models were used to successfully separate a range of structurally diverse pharmaceutical compounds by predicting the best solvent systems to carry out the separation on the CCC/CPC using nothing but their molecular structure.

Thesis (MIng)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Fouling is readily acknowledged as one of the most critical problems limiting the wider application of membranes in liquid separation processes. A better understanding of fouling layer formation and its monitoring is needed in order to improve on existing cleaning techniques. Plant operation can be optimised if fouling can be monitored by noninvasion means either on the plant itself or on an attached monitoring device. The overall scope of this research was to develop a non-destructive, real-time, in situ visualisation technique or device for concentration polarisation and fouling layer monitoring. Ultrasonic-time-domain-reflectometry (UTDR) was employed as a visualisation technique to provide real-time characterisation of the fouling layer. A 24 cm-long rectangular flat sheet aluminium cell was designed and used as separation device for a desalination system. The experimental results obtained using this module confirmed that there are an excellent correspondence between the flux decline behaviour and the UTDR response from the membrane. The ultrasonic technique could effectively detect fouling layer initiation and growth on the membrane in real-time. In addition to the measurement of fouling, the ultrasonic technique was also successfully employed for monitoring membrane cleaning. Since no real-time permeation data is available during cleaning operations in industrial applications, a UTDR monitoring device may prove to be a very valuable technique in optimising cleaning strategies. The technique was further tested on an 8-inch diameter spiral wrap industrial module and good results were obtained. Stagnant zones, as well as flux flow behaviour inside the module could be determined. However, more research IS needed to fully understand the complex phenomena inside a spiral wrap module. Overall, the UTDR technique and its use in monitoring devices have a major impact in the membrane industry due to its extremely powerful capabilities. / AFRIKAANSE OPSOMMING: Membraan-bevuiling of -verstopping is die grootste struikelblok wat die algemene aanwending van membrane vir verskillende watersuiweringsprosesse negatief beinvloed. 'n Beter begrip van membraan-bevuiling, asook beter metingsmetodes daarvan is nodig om op bestaande skoonmaaktegnieke te verbeter. Die hoofdoel van hierdie studie was die ontwikkeling van 'n nie-destruktiewe-in-lyn visuele tegniek vir die meting van konsentrasie polarisasie en membraan-bevuiling. Deur gebruik te maak van ultrasoniese klank golwe, is 'n tegniek ontwikkel wat 'n direkte visuele aanduiding kon gee van die toestand van membraan-bevuiling binnein die module. 'n Reghoekige aluminium-module, 24 cm lank, is ontwerp en gebou waarbinne die membraan geplaas is vir die skeidingsproses. Resultate dui daarop dat daar 'n uitstekende verband bestaan tussen die afname in permeaatvloei en die ultrasoniese eggo vanaf die membraan. Die ultrasoniese tegniek kon die vorming van en toename in membraan-bevuiling doeltreffend karakteriseer. In teenstelling hiermee, is die tegniek ook suksesvol aangewend om die skoonmaak-proses van membrane te ondersoek. Met min of geen data beskikbaar vir die skoonmaak-proses van membrane in die industriële sektor, het die tegniek enorme potensiaal in die optimisering van bestaande skoonmaak-tegnieke. Die tegniek is verder aangewend op 'n industriële 8-duim deursnee spiraal-module en goeie resultate is verkry. Stagnante sones asook vloed-vloei-patrone binne-in die module kon suksesvol bepaal word. Baie navorsing is egter nog nodig om die ingewikkelde data wat gegenereer word tydens die ondersoek van 'n spiraal-module ten volle te verstaan. Die enorme potensiaal en moontlikhede van die ultrasoniese tegniek kan die begin wees van 'n revolusie in die membraan-industrie.

O minério de ferro produzido no complexo de Carajás traz consigo características mineralógicas que conferem um elevadíssimo teor de Fe em todas as suas frações granulométricas. Dessa forma, ao final da cadeia produtiva, tanto os produtos comerciais mais grosseiros quanto os finos contem cerca de 62% de Fe contido na sua composição. Importante destacar que em Carajás as fases no processamento desse minério são apenas para cominuição e classificação por tamanho. Não existem etapas de concentração e os produtos são diferenciados por suas respectivas curvas granulométricas: o “granulado” - mais grosseiro (> 13 mm), o “Sinter-Feed” (< 13 mm e > 0,5 mm) e o “pellet feed” (< 0,15 mm). Garantir a correta distribuição granulométrica da matéria prima é uma premissa de mercado. A ultima etapa da classificação é feita através de hidrociclones e gera um overflow ultrafino de altíssima superfície específica maior que 6.500 Blaine e com 45% até 95 % < 7 μm. E ainda possui um elevado teor de Fe - cerca de 62 %. Dessa forma os objetivos gerais dessa pesquisa buscaram a solução para essa oportunidade de recuperar e vender esses rejeitos. O estudo sugeriu através de ensaios com tecnologias capazes de desaguar os ultrafinos gerados para 9,00 % de umidade, que é o valor que permite a movimentação e o manuseio desses rejeitos, além de permitir sua incorporação na blendagem de produtos mais grossos. Desse modo, foram realizados experimentos em diversos laboratórios externos e em escala piloto na Usina de Carajás com amostras dos dois rejeitos ultrafinos das duas fases de hidrociclonagem: o natural e o moído. Ficou evidente que o equipamento tem de combinar necessariamente e de forma eficiente dois fatores essências ao desaguamento: elevadíssimas pressões e altas temperatura na operação desses ultrafinos. A produtividade atingida foi da ordem de 50 t/h x m² para o rejeito da hidrociclonagem do Sinter Feed e 40 t/h x m² para o rejeito dos hidrociclones da Moagem. / The Iron ore that is produced in Carajás mining complex brings mineralogical characteristics that give a very high Fe content in all its size fractions. Thus, at the end of the production chain both coarser and fine contains about 62% Fe contained in its composition. Importantly, in Carajás stages in the processing of this ore are for reduction and classification by size. There is thus no concentration steps and products are differentiated by their respective size distribution curves: the "grain" - coarser (> 13 mm), the "Sinter-Feed" (<13 mm and > 0.5 mm) and the "pellet feed" (<0.15 mm). Ensure proper particle size distribution of the raw material is a market premise. The last step of classification is made using hydrocyclones and generates an overflow ultrafine high specific surface area greater than 6.500 Blaine and with 45% to 95% <7 μm. And has a high Fe content - about 62%. The overall objectives of this research sought the solution to this opportunity to recover and sell these “tailings”. The study suggested by testing with technologies capable of flowing into the ultrathin generated to 9.00% of moisture, which is the value that allows movement and handling these wastes, and allows their incorporation into the blending of thicker products. Thus, experiments were carried out in several external laboratories and pilot-scale plant in the Carajás with samples of both ultrafine “tailings” of the two phases of hydrocycloning: the natural and the ground. It was evident that the equipment must necessarily match and two efficiently factors essences to dewatering: very high pressure and high temperature operation of these “tailings”. The productivity achieved was around 50 t/h x m² in reject of the Sinter Feed hydrocycloning and 40 t/h x m² to reject of the grinding hydrocyclones.

O processo de espessamento e clarificação dos efluentes das usinas de beneficiamento de carvão mineral com a adoção de sedimentadores é uma prática consagrada ao longo de todo o mundo uma vez que é necessário o reaproveitamento da água utilizada tanto por questões econômicas como ambientais. O primeiro sedimentador, tipo espessador, a entrar em operação industrial na região carbonífera de Santa Catarina foi instalado na Mina Barro Branco da Carbonífera Rio Deserto em 2007. O equipamento era dotado de lamelas de PVC e foi instalado como alternativa às bacias de decantação, que apresentam alto custo de construção e operação. Contudo, o equipamento se mostrou ineficaz devido a deposição de sólidos nas lamelas. Essa dificuldade levou a adoção de outros modelos de sedimentadores de fluxo vertical que não utilizam lamelas. Esse trabalho apresenta os dados disponíveis da operação do equipamento com as lamelas na Mina Barro Branco e resultados atuais da operação dos sedimentadores da Mina Esperança sem lamelas. Nesse segundo caso foi medida a vazão, concentração de sólidos e dos metais ferro, alumínio e manganês, nos fluxos de entrada e saída. No efluente clarificado mediu-se ainda o pH e a turbidez. Registraram-se dados de uma operação satisfatória, com impacto importante na redução dos custos no transporte e deposição dos rejeitos finos e no tratamento do overflow clarificado possibilitando o descarte de acordo com a Legislação Ambiental. / The process of thickening and clarifying the effluents of mineral coal processing plants with the use of settlers is a well-established practice throughout the world since it is necessary to reuse the water used for both economic and environmental reasons. The first settler, a thickener type, to enter into industrial operation in the Santa Catarina coal region was installed at the Barro Branco Mine of the Carbonifera Rio Deserto in 2007. The equipment was equipped with PVC lamellae and was installed as an alternative to the decantation basins, which have a high cost of construction and operation. However, the equipment proved to be ineffective due to deposition of solids in the lamellae. This difficulty led to the adoption of other models of vertical flow settlers that do not use lamellae. This work presents the available data of the operation of the equipment with lamellae in the Mina Barro Branco and current results of the operation of the settlers in the Mina Esperança without lamellae. In this second case the flow, concentration of solids and iron, aluminum and manganese metals in the inflow and outflow were measured. In the clarified effluent the pH and turbidity were also measured. Data were recorded for a satisfactory operation, with a significant impact on the reduction of costs in the transportation and deposition of the fine tailings and in the treatment of the clarified overflow, allowing the disposal according to the Environmental Legislation.