Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência e Engenharia dos Materiais, Florianópolis, 2015. / Made available in DSpace on 2017-04-11T04:05:24Z (GMT). No. of bitstreams: 1 344806.pdf: 7611287 bytes, checksum: f34ef88aee42afcbe8133dfda2d66deb (MD5) Previous issue date: 2015 / O presente trabalho objetivou, através de incorporação dos íons de estrôncio (Sr2+), controlar parâmetros de síntese na formação de diferentes morfologias e fases cristalográficas de fosfatos de cálcio. Foi feito um estudo sobre a composição, a estrutura e a formação de tecidos duros e a família de materiais relacionados a estes, bem como seus modos de crescimento e a estrutura de cristais formados relacionados à biomineralização natural e seu biomimetismo influenciado por substituições iônicas em rede cristalina. Para a síntese, por precipitação química de soluções aprimoradas, procede-se com a reação entre as soluções de Ca(NO3)2 e Sr(NO3)2 precipitadas em (NH4)2HPO4 com relação Ca/P=1,67 e com 19 at.%, 40 at.% e 53 at.% de íons Sr2+, em meio ácido a básico em pH=6, 7 e 8. As amostras foram caracterizadas por difração de raios-X (DRX), microscopia eletrônica de varredura (MEV) e espectroscopia de raios-X por dispersão de energia (EDS). Foram encontradas as fases cristalográficas brushita (DCPD), monetita (DCP), hidroxiapatita (HAP) monoclínico e hexagonal. A incorporação supersaturada de íons Sr2+ em pH = 6,0 altera a formação de cristais, afeta sua cristalização, influencia o equilíbrio iônico na geminação e nucleação do cristal formando mesocristais com aparecimento de fases preliminares de brushita e monetita com morfologias em placas e/ou pétalas, induzindo posteriormente ao processo de auto-organização e orientação preferencial no plano (020) da HAP monoclínica com crescimento até estágio final de hábito cristalino pseudohexagonal. Em meios com pH = 7 e 8 há cristalização de nanoesferas de hidroxiapatita nucleadas a partir de incorporação não supersaturada de íons Sr2+.<br> / Abstract : Through the addition of strontium ions (Sr2+), this study aims at controlling synthesis parameters in the formation of morphologies and crystallographic phases of calcium phosphate. A study was conducted on the composition, structure, formation of hard tissues and the group of materials related to them, as well as its growth and the formed crystal structures related to natural biomining and its biomimicry influenced by ionic substitutions. The synthesis, through chemical precipitation of enhanced solutions, was the reaction between the solutions of Ca (NO3)2 and Sr (NO3)2 precipitated with (NH4)2HPO4 with Ca/P = 1.67 and 19 at.%, 40 at.% and 53 at.% of Sr2+ ions in the acidic to basic pH = 6, 7 and 8. The samples were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy of X-ray (EDS). XRD analysis found the brushite crystallographic phases (DCPD), monetite (DCP), monoclinic and hexagonal hydroxyapatite (HAP). The supersaturated adding of Sr2+ ions at pH 6.0 alters crystal formation, affects its crystallization, influences the ionic balance in the germination and nucleus of the crystal, forming mesocrystals with preliminary phases of brushite and monetite with plate and/or petal morphologies. Thus leading to the process of self-organization and preferential orientation on plan (020) from the monoclinic HAP with final stage growth of pseudo hexagonal habit. Whereas, pH=7.0 and 8.0 induces the crystallization of nucleated hydroxyapatite nanospheres from the non-supersaturated addition of Sr+2 ions.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química / Made available in DSpace on 2012-10-19T13:55:22Z (GMT). No. of bitstreams: 1 230918.pdf: 340870 bytes, checksum: 146df8d49730f878f49fbe583ef6e323 (MD5) / Quitosana ditiocarbamato de potássio (ChitDTCK) foi sintetizado e caracterizado por análise elementar e 13C RMN em estado sólido. O grau de substituição GS (numero de substituíntes por 100 unidades de 2-amino-2-deoxyglucopiranose) e molalidades dos grupos foram calculados para os substituíntes acetilamino, amino e ditiocarbamato na quitina, quitosana e ChitDTCK. Um estudo comparativo da retenção e recuperação de íons Cu(II), Co(II) e Ni(II) foi realizado com a quitina, quitosana e ChitDTCK a 30 oC, pH 6,0 (0,1M succinato). Para tal efeito foram calculadas as constantes de estabilidade (KX), para o equilíbrio heterogêneo, ChitX + M(II) ChitXM(II) onde X representa os ligantes acetilamino, amino e ditiocarbamato e M(II) = Cu(II), Co(II) e Ni(II). Também foram calculadas as constantes de instabilidade ( ), pelo equilíbrio inverso. Assumiu-se que os complexos apresentam a razão 1:1 metal-ligante com respeito a cada grupo. Para Cu(II) os valores das constantes de estabilidade KX foram 44,5 (acetilamino), 9,4x103 (amino), e 3,5x103 (ditiocarbamato). As constantes de instabilidade foram 5,0 x10-3 (acetilamino) e 1,90x10-5 (amino).Para Co(II) as constantes foram KX 0,69 (acetilamino) e 1,5x103 (amino); 1,80x10-2 (acetilamino) e 2,5x10-5 (amino). Para Ni(II) os valores foram KX 0,7 (acetilamino) e 1,1x104 (amino); 1,2x102 (acetilamino) e 4,1x10-6 (amino). É proposto que na presença de succinato a principal espécie presente em solução de ions aqua Cu(II) deve ser o complexo sem carga Cu(II)-succinato, que impede que os grupos ligantes (acetilamino, amino, DTC) formem complexos maiores que 1:1 e pode também explicar que a constante de estabilidade para o DTC fosse menor que o do grupo amino. O método permite a caracterização da habilidade quelante de cada grupo na matriz da quitosana com respeito a íons metálicos.

Orientador : Prof. Dr. Leni C. Akcelrud / Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa: Curitiba, 14/05/2015 / Inclui referências : f. 85-94 / Área de concentração : Química Orgânica / Resumo: O estudo de dois sistemas poliméricos complexados com íon európio foi o objeto de estudo desta Tese. Em ambos foram usados copolímeros alternados de um derivado de polifluoreno, sendo no primeiro caso o co-monômero a bipiridina, e no segundo a terpiridina. Os copolímeros originais foram complexados com íon európio, e os resultados foram interpretados utilizando as propriedades fotofísicas do polímero original não complexado e um composto modelo de baixa massa molar com a mesma estrutura da unidade complexada no polímero. Na primeira série (série 34), estudou-se as propriedades termocrômicas dos materiais e como a cadeia polimérica pode ter suas propriedades afetas pelo complexo de európio. Dois efeitos importantes foram detectados: separação inter-cadeias impedindo a agregação e a independência da intensidade de emissão do polímero com a variação de temperatura, na janela de 170 - 330 K. O efeito termocrômico apresentado neste trabalho foi reportado pela primeira vez e abre um novo caminho para a criação de nanotermômetros, uma vez que o polímero pode agir como um "padrão interno", permitindo assim a construção de dispositivos mais simples. Na segunda série (série 66), as propriedades do polímero complexado com európio foram investigadas e comparadas com o esqueleto polimérico não complexado e um complexo de európio como composto modelo. Os estudos de fotoluminescência foram medidos em estado sólido e solução e mostraram a transferência de energia através da sobreposição espectral entre os espectros de absorção do complexo de Eu3+ e de emissão do polímero não complexado, acarretando na extinção da emissão azul do polímero quando complexado com o metal. Também é apresentado um estudo de fotoluminescência teórico detalhado realizado com DFT (TD-DFT) e com o pacote de luminescência LUMPAC. A precisão dos cálculos teóricos foi conseguida através da comparação com os valores experimentais. / Abstract:Two types of fluorene derivatives containing complexed sites with the europium ion were studied. In the first one, composed by alternated fluorene and pyridine units (LaPPS34 series) a thermochromic effect was observed. The interpretation of the phenomenon was based on the photophysical properties of the non-complexed polymer and a low molecular mass model compound having the same structure of the complexed site in the polymer. To the naked eye, the thermochromism was characterized by a strong red at low temperatures (170 ? 260 K, due to Eu3+ ion) and a blue color at higher ones (280 ? 330 K, due to fluorene). Absorption and emission spectra, time-resolved measurements, and theoretical simulations showed that the polymer chain does not affect the europium photophysical properties, but the opposite occurred: the ion insertion precluded interchain aggregation, and the backbone emission did not vary with temperature variation, in the range of 170 - 330 K. To the best of our knowledge, this effect is reported for the first time and opened a new avenue for the design of nanothermometers, since the polymer can act as a "built-in standard", thus allowing the construction of much simpler devices. In the second structure terpyridine were placed in alternating fashion with the fluorene units (LaPPS66 series). As before photophysical studies were undertaken to interpret the observed effects, using the non-complexed backbone (LaPPS66) and a low molecular weight compound of similar chemical structure of the ligand/Eu3+ site (LaPPS66M) as a model compound. The photoluminescence studies were measured in solid and solution state showing the occurrence of polymer-to-Eu3+ energy transfer brought about by the spectral overlap between the absorption spectra of the Eu3+ complex and the emission of the polymer backbone. A detailed theoretical photoluminescence study performed with time-dependent DFT (TD-DFT) calculations and with the recently developed LUMPAC luminescence package is also presented. The high accuracy of the theoretical calculations was achieved through the comparison with the experimental values.

G-quadruplexes represent a versatile sensing platform for the construction of label-free molecular detection assays due to their diverse structures that can be selectively recognized by G-quadruplex-specific luminescent probes. In this thesis, we have explored the applications of the label-free G-quadruplex-based luminescent detection platforms for the detection of biomolecules and metal ions. Chapter 1 provides an overview of the principles and recent developments of the field of luminescent oligonucleotide-based probes, and highlighting in particular the use of the “label-free” strategy for the construction of simple and inexpensive sensing platforms. Chapter 2 introduces the basic experiments performed during the course of this thesis, including UV/Vis absorption spectroscopy, luminescence spectroscopy, nuclear magnetic resonance, mass spectrometry circular dichroism spectroscopy and G-quadruplex fluorescent intercalator displacement assay. Chapter 3 describes a G-quadruplex-based switch-on luminescence assay for the detection of gene deletion using iridium(III) complex 1 as a G-quadruplex-selective probe. Our method is based on the formation of a split G-quadruplex upon hybridization of two critically designed quadruplex-forming sequences with the mutant DNA sequence, resulting in a “switch-on” luminescence response. Chapter 4 describes a label-free, oligonucleotide-based, switch-on luminescence detection method for T4 polynucleotide kinase activity using a G-quadruplex-selective luminescent iridium(III) complex 2. The application of the assay for screening potential T4 PNK inhibitors is also demonstrated. To our knowledge, this is the first metal-based assay for PNK activity that has been reported in the literature. Chapter 5 describes a label-free oligonucleotide-based luminescence switch-on assay for the selective detection of sub-nanomolar Pb2+ ions in aqueous solution and real water samples. Iridium(III) complex 1 was employed as a G-quadruplex-specific luminescent probe and a guanine-rich DNA sequence (PS2.M, 5.-GTG3TAG3CG3T2G2-3.) was employed as recognition unit for Pb2+ ions. The assay could detect Pb2+ ions in aqueous media with a limit of detection of 600 pM, and also exhibited good selectivity for Pb2+ ions over other heavy metal ions. Furthermore, the application of the assay for the detection of Pb2+ ions in spiked river water samples was demonstrated. Chapter 6 describes a label-free G-quadruplex-based luminescent switch-on assay for the selective detection of micromolar histidine in aqueous solution. Iridium(III) complex 8 was employed as a G-quadruplex-specific luminescent probe while a guanine-rich oligonucleotide (Pu27, 5.-TG4AG3TG4AG3TG4A2G2-3.)/cupric ion (Cu2+) ensemble was employed as a recognition unit for histidine. The assay could detect down to 1 µM of histidine in aqueous media, and also exhibited good selectivity for histidine over other amino acids with the use of the cysteine-masking agent N-ethylmaleimide. Furthermore, the application of the assay for the detection of histidine in diluted urine samples was demonstrated. Chapter 7 summarizes the work that was conducted in this thesis, and the future outlook of G-quadruplex-based sensing is presented.

L’avènement de sources lumineuses performantes et compactes à base de silice dopée par des ions de terres rares (TR) passe par l’obtention de rendements d’émission élevés, ce qui nécessite une bonne dispersion de ces ions. Les vitrocéramiques, associant une matrice vitreuse avec des nanocristaux (NC), permettent une telle dispersion et fournissent néanmoins une transparence optique adéquate. D’autre part, les NC présentent une absorption de lumière spectralement large et peuvent transférer leur énergie vers les ions de TR pour améliorer l’efficacité d’émission.Dans ce travail, des vitrocéramiques à base de silice contenant des NC de SnO2 ont été élaborées sous forme de couches minces et de massifs par la technique sol-gel. Les propriétés optiques et structurales des systèmes sous forme de couches minces ont été comparées à celles des systèmes massifs. Plusieurs paramètres, tels que la concentration maximale d’étain, les températures de cristallisation et de densification, diffèrent selon la morphologie des matériaux. L’influence réciproque entre la matrice de silice et les NC de SnO2 a été étudiée par l’utilisation conjointe de plusieurs techniques d’analyses telles que les spectroscopies vibrationnelles, la DRX, la MET, la porosimétrie BET… L’ajout d’étain retarde la densification de la matrice, laissant une porosité résiduelle.La luminescence des ions Er3+ et Eu3+ (largeur de bande d’émission, durée de vie) a montré clairement l’existence de 2 types de sites hôtes, l’un cristallin et l’autre amorphe. Enfin, les NC de SnO2 favorisent la dispersion des ions de TR, conduisant à des durées de vies encourageantes et à un transfert d’énergie entre cristal et TR. / The obtention of efficient and compact light sources based on silica doped with rare earth (RE) ions demands high emission yields, which require a good dispersion of RE ions. Glass-ceramics, associating a glass with nanocrystals (NCs), allow such a dispersion and still assure adequate optical transparency. In addition, the NCs have broad absorption bands and can transfer their energy to the RE ions, thus improving the emission efficiency. In this work, silica-based ceramics containing SnO2 NCs were prepared as thin films and bulk by the sol-gel technique. The optical and structural properties of the thin films were compared with those of monoliths. Several parameters, such as the maximum concentration of tin, the temperature of crystallization and of densification, differ according to the morphology of the materials. The interaction between the silica matrix and SnO2 NCs was studied by combining several analytical techniques such as vibrational spectroscopies, XRD,TEM, porosimetry BET…The addition of tin retards the densification of the matrix, leaving a residual porosity. The luminescence of Er3+ and Eu3+ (emission bandwidths, lifetimes) clearly shows the existence of two types of host sites, one crystalline and the other amorphous. Finally, the SnO2 NCs promote the dispersion of the RE ions, leading to longer lifetimes and an energy transfer between crystal and RE.

Made available in DSpace on 2014-10-09T12:24:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:07:38Z (GMT). No. of bitstreams: 1 01012.pdf: 1414646 bytes, checksum: 44ebcb7bdde5ad3dd54e624dfb18a42c (MD5) / Tese (Doutoramento) / IEA/T / Instituto de Quimica, Universidade de Sao Paulo - IQ/USP

Made available in DSpace on 2016-09-27T13:40:10Z (GMT). No. of bitstreams: 0 Previous issue date: 1997-10-01. Added 1 bitstream(s) on 2016-09-27T13:45:24Z : No. of bitstreams: 1 000027249.pdf: 1097912 bytes, checksum: ff97431a047b903f477cf29318e2eceb (MD5) / O trabalho teve como objetivo avaliar a importância da presença na água dos íons Ca2+, K+, HCO3-, Br-, Sr2+, Mn2+, HPO42-, Li+, MoO42-, S2O32-, Al3+, Rb+, Zn2+, Co2+ e Cu2+ para o desenvolvimento do Macrobrachium rosenbergii no estágio larval II, visando fornecer subsídios para a otimização da composição iônica da água salobra utilizada na larvicultura dessa espécie. A água do mar artificial foi preparada conforme a formulação usada no setor de Carcinicultura do CAUNESP, cujos sais são classificados em macroelementos (MA), microelementos (MI) e elementos traços (ET). Foram realizadas cinco etapas seqüencialmente. Na primeira avaliaram-se águas salobras preparadas com MA + MI + ET, sendo que, em cada tratamento, foi eliminado um dos seguintes elementos traços: alumínio, rubídeo, zinco, cobalto e cobre. Na segunda a água foi preparada com MA + MI e, em cada tratamento adicionou-se um dos elementos traços. Na Fase 3 foram analisadas formulações preparadas com MA + MI, sendo que, em cada tratamento foi eliminado um dos seguintes microelementos: bromo, estrôncio, manganês, fosfato, lítio, molibdato e tiossulfato. Na Fase 4 a água foi preparada com MA e, em cada tratamento, adicionouse um dos microelementos. Na última fase foram avaliados cinco meios preparados com MA + Br-; em cada tratamento foi eliminado um dos seguintes íons: cálcio, potássio, bicarbonato e brometo. Todas as etapas foram realizadas seguindo um delineamento inteiramente casualizado com três repetições (três béqueres) para cada tratamento. Aplicou-se um teste de inanição, que consistiu na estocagem de seis larvas de M. rosenbergii, no estágio larval II, em béqueres de 30 ml, contendo 15 ml de água salobra a 12‰, mantidos em temperatura ambiente em torno de 30ºC. A cada oito horas contou-se o número de larvas vivas em cada unidade experimental, para o cálculo do tempo médio de vida em todos os tratamentos. Os dados foram... / The importance of the ions presence in water Ca2+, K+, HCO3-, Br-, Sr2+, Mn2+, HPO42-, Li+, MoO42-, S2O32-, Al3+, Rb+, Zn2+, Co2+ and Cu2+ on the development of Macrobrachium rosenbergii at the larval stage II was evaluated, in order to obtain information to optimize the ionic composition of the brackish water used to larviculture this species. Artificial sea water was prepared according to the formulation used by the Crustacean Rearing Laboratory of CAUNESP. In this formula, salts are classified in major elements, minor elements and trace elements. In this experiment, a starvation test was applied. It consisted in keeping larvae of M. rosenbergii, at the stage II, in 30 ml beakers containing 15 ml of brackish water (12‰). The beakers were kept at about 30ºC of controlled air temperature. There were five phases conducted sequencially (phases 1 to 5). Brackish water of different ionic composition, in relation to the trace elements Al3+, Rb+, Zn2+, Co2+ and Cu2+, were evaluated on the first two phases. Differents formulas containing the minor elements Br-, Sr2+, Mn2+, HPO42-, Li+, MoO42- and S2O32 were evaluated on phases 3 and 4. And five media with differents ionic composition containing the major elements Ca2+, K+, HCO3-, and the minor element Br-, were evaluated on phase 5. Three beakers were used per treatment, and each was stocked with six larvae, in a complete randomized experimental design. In order to estimate the average life time, the number of larvae that survived the treatment was counted every eight hours. The data were analyzed through ANOVA and the means were compared by the Tukey test. The trace elements Al3+, Rb+, Zn2+, Co2+ and Cu2+ and the minor elements Sr2+, Mn2+, HPO42-, Li+, MoO42- and S2O32 did not allow an increase of the larvae life time at the second larval stage. These ions could, however, become essential to this organism at the other stages, or could show a retardation effect. Sodium thiosulphate must be added

Made available in DSpace on 2014-06-11T19:29:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-06Bitstream added on 2014-06-13T19:17:27Z : No. of bitstreams: 1 soares_iv_me_ilha.pdf: 1133733 bytes, checksum: a19d20f6216ce2f0bbb1477213bb7915 (MD5) / Este trabalho descreve as sínteses e caracterizações de silsesquioxanos organofuncionalizados com tiouréia (T8-Pr-TU), 2,2’-dipiridilamina (T8-Pr-DPA) e 2-Amino-1,3,4-Tiadiazol (T8-Pr-ATD). Os materiais foram caracterizados por: espectroscopia na região do infravermelho (FTIR), ressonância magnética nuclear 29Si e 13C no estado sólido (RMN) e análise elementar. Nos estudos de batelada para os materiais, foram utilizados os íons metálicos de Cd (II), Cu (II), Ni (II) e Co (II) e os solventes foram água e etanol. Determinou-se a dose de adsorvente na solução e o tempo de equilíbrio, na qual, para o material T8-Pr-TU em todos os meios e metais, a capacidade máxima de adsorção ocorreu em 50 mg de adsorvente, e o equilíbrio de adsorção foi de aproximadamente 9 minutos para todos os solventes e íons metálicos, enquanto que, para o T8-Pr-DPA em todos os meios e metais, a capacidade máxima de adsorção ocorreu com 10 mg de adsorvente e tempo de equilíbrio de 10 minutos; já para o T8-Pr-ATD, independentemente do solvente e dos metais, a capacidade máxima de adsorção foi em 50 mg de adsorvente e tempo de equilíbrio de 10 minutos. Estudou-se ainda a capacidade máxima de adsorção (Nf) para os solventes, na qual a capacidade máxima se deu em meio etanólico > aquoso. O efeito dos contra-íons Cl-, Br- e ClO4- foi estudado para todos os materiais, na qual observou-se que para os três adsorventes a capacidade de adsorção seguiu a seguinte ordem: Cl- > Br- > ClO4-. Em seguida, as isotermas de adsorção foram ajustadas pelos modelos Langmuir, Freundlich, Temkin e Dubinin-Radushkevich (D-R). Para cinética de adsorção dos metais, foram usados três modelos cinéticos como pseudo-primeira-ordem, pseudo-segunda-ordem e Elovich. Os modelos de Langmuir e Elovich foram os mais apropriados para descrever os dados... / This work describes the synthesis and characterization of silsesquioxanes organofuncionalizados with thiourea (T8-Pr-TU), 2,2 '-dipyridylamine (T8-Pr-DPA) and 2-Amino-1,3,4-thiadiazole (T8-Pr-ATD). The materials were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance 29Si and 13C solid state (NMR) and elemental analysis. In studies to batch materials were used for metal ions of Cd (II), Cu (II), Ni (II) and Co (II) and the solvents were water and ethanol. It was determined the dose of adsorbent in the solution and equilibrium time in which, for the material T8-Pr-TU in all ways and metals, the maximum adsorption capacity observed in 50 mg of adsorbent, and adsorption equilibrium was about 9 minutes for all metal ions and solvents, whereas for T8-Pr-DPA in all ways and metals, the maximum adsorption capacity was 10 mg of adsorbent and equilibration time of 10 minutes, whereas for T8-Pr-DPA, regardless of solvent and metals, the maximum adsorption capacity was 50 mg of adsorbent and equilibration time of 10 minutes. It was also studied the maximum adsorption capacity (Nf) for solvents, in which the maximum capacity was in ethanolic > aqueous. The effect of the counter ions Cl-, Br-and ClO4- was studied for all materials in which it was observed that the three adsorbents for the adsorption capacity followed the order: Cl-> Br-> ClO4-. Then the adsorption isotherm models were fitted by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (DR). For adsorption kinetics of metals, three kinetic models were used as pseudo-first-order, pseudo-second-order and Elovich. The Langmuir model and Elovich were most suitable to describe the data and kinetics of adsorption, respectively, of all materials. From the model isotherm DR, one can calculate the free energy (E)... (Complete abstract click electronic access below)

Thesis (MTech (Chemical Engineering)--Cape Technikon, Cape Town, 2002 / This study is the first phase of an investigation into an alternative process to recover base metals from solution, namely ion exchange. An identified ion exchange resin was employed to study the recovery of copper, nickel and cobalt from electrolytic solutions. The main focus of the investigation was the prediction of equilibrium conditions in this multi-component system using a batch configuration. In order to predict equilibrium conditions. existing multi-component isotherms such as Fritz and Schleunder were tested. It has been shown that traditional isothem15 did not accurately predict equilibrium conditions. hence the need for development of new isotherms. Essentially two approaches were followed in the development of new isotherms namely. an effective concentration approach as well as a heat transfer approach. Both yielded positive outcomes with the effective concentration approach proving to be the most accurate. In addition to these two approaches a thermodynamical approach was also tested which also showed favourable predictions for Cu loading

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology / Throughout the world, many water resources are polluted by industrial and domestic effluents, acid mine drainage, etc. The increasing awareness and concern about the environment has motivated in the recent years extensive research into developing new efficient, cost effective and environmentally sound technologies to treat industrial solutions bearing metals and sludges. From the literature review, much research has been, and is still being devoted to the performance of solvent extraction (SX) of aluminium or sulphate in acidic solutions and how to improve such performance. There is a general lack of information on liquid-liquid extraction of aluminium or sulphate in an alkaline solution. Thus, the need for a systematic investigation into the solvent extraction of aluminium and sulphate in an alkaline medium was important. This thesis focuses on the study of solvent extraction of aluminium and sulphate from alkaline solutions using Trioctylmethylammonium chloride, (Aliquat 336), in Kerosene as diluent.