The initial goal of the project was to develop a more effective method for the purifications of oligonucleotides. This was achieved by developing a method of ion-exchange based on-column deprotection. The resulting method was compared to preestablished methods using LC-MS fraction analysis evaluated according to a purityscore with the acceptance criteria of ≥ 0.45. The on-column deprotection was shownto achieve a purity score > 0.6 for both of the fully thiolated and the partially thiolatedoligonucleotides while the other methods of regular ion-exchange chromatography,ion-pair chromatography and reversed phase chromatography only achieved a purityscore of ≥ 0.6 for only the fully thiolated oligonucleotides. The ion-exchange methodsbecame dependent on more chaotropic agents than expected, but the results gainedduring the resin screening portion of the project may provide a remedy. During theresin screening, the effects of two factors, pore size and ligand density, were investigated. Showing that the pore size did not affect the oligonucleotides to any extent,resulting in the ligand density being the major affecting factor. When studying thedifferent resins, a trend of lower retention with lower ligand density was observed.These results provide a foundation to use lower ligand density resins compatible withless harsh conditions when applying the on-column deprotection in future optimization for the purification of pharmaceutical oligonucleotides. / Syftet med projektet var att utveckla en mer effektiv metod för upprening av oligonukleotider. Detta uppnåddes genom att utveckla en metod för direkt avlägsning av denskyddande gruppen direkt på kolonnen baserat på jonbytes kromatografi. Den resulterande metoden jämfördes med tidigare etablerade metoder genom LC-MS fraktionsanalys och utvärderades enligt ett renhetsbetyg med acceptanskriterier på ≥ 0,45.Metoden visade sig uppnå ett renhetsbetyg > 0,6 för både de fullständigt tiolieradeoch delvis tiolierade oligonukleotider, medan andra metoder som vanlig jonutbyteskromatografi, jonpars-kromatografi och reversed phase-kromatografi endast uppnådde ett renhetsbetyg ≤ 0,6 för fullständigt tiolierade oligonukleotider. Jonutbytesmetoderna blev beroende av fler kaotropiska kemikalier än förväntat, men resultatenfrån resin undersökningen under projektet kan ge en lösning på detta. Under resinundersökningen utreddes effekterna av två faktorer, porstorlek och liganddensitet. Detvisades att porstorleken inte påverkade oligonukleotiderna i någon större utsträckningoch att liganddensiteten var den avgörande faktorn. Vid studier av olika resiner observerades en trend mot lägre retention vid lägre liganddensitet. Dessa resultat ger engrund för att använda resiner med lägre liganddensitet i den utevecklade metoden.Vilket bör tillåta mindre hårda förhållanden vid fortsatt optimering av uppreningenför farmaceutiska oligonucleotider.

Tracertests stellen heute einen integralen Bestandteil im Repertoire der hydro(geo)logischen Charakterisierungstechniken dar. Insbesondere konservative Stoffe werden zur Bestimmung von hydraulischen Reservoir- und Aquiferparametern eingesetzt. Diese Stoffe verhalten sich weitestgehend inert und unterliegen somit nur vernachlässigbaren physikochemischen Wechselwirkungen während ihrer Verweilzeit im untersuchten Geosystem. Im Gegensatz dazu stellt der Einsatz nicht-konservativer organischer Stoffe als Tracer einen relativ neuen Ansatz dar, welcher das Potential birgt, zusätzliche Informationen zu ablaufenden Untergrundprozessen zu gewinnen, sofern die Wechselwirkungsarten und somit das Tracerverhalten bekannt sind. Folglich ist die genaue Kenntnis potentieller Transportprozesse und deren Abhängigkeiten eine unabdingbare Voraussetzung für eine erfolgreiche Interpretation dieser Tracer. In diesem Zusammenhang ist die Sorption an Festphasen für zahlreiche gelöste organische Verbindungen der wohl bedeutendste physikochemische Transportprozess. Aus diesem Grund ist die systematische Untersuchung von Sorptionsprozessen und deren Abhängigkeiten von den Moleküleigenschaften bzw. Randbedingungen ein Hauptbestandteil der hier vorgestellten, kumulativen Dissertationsschrift. Die aus den Sorptions-untersuchungen abgeleiteten Schlussfolgerungen wurden in die Entwicklung eines neuen, reaktiven Reservoir-Tracers für die geologische Speicherung von CO2 mit einbezogen. Um einen Überblick über das Sorptionsverhalten organischer Verbindungen mit unterschiedlichen Funktionalitäten zu gewinnen, wurde zunächst der pH-abhängige Stofftransport mehrerer dissoziierbarer Arzneimittelwirkstoffe (Säuren, Basen, Zwitter) mit Hilfe von Sedimentsäulenexperimenten untersucht. Hierzu wurden die Sorptionskoeffizienten bestimmt und mit den vorausberechneten Ergebnissen zweier Korrelationsansätze verglichen. Eine starke pH-Abhängigkeit zeigte die Sorption für alle Moleküle mit einem pKS-Wert im oder nahe des untersuchten pH-Bereiches. Eine zufriedenstellende Vorhersage war nur für neutrale und anionsche (saure) Verbindungen möglich. Im Gegensatz dazu war die Sorption der kationischen (basischen) und zwitter-ionischen Verbindungen stärker als erwartet. Als Ursache dafür kann das Auftreten zusätzlicher, elektrostatischer Sorptionsmechanismen angesehen werden, welche in den konventionellen Korrelationsansätzen nicht berücksichtigt werden. Somit konnte unter anderem erwartet werden, dass auch Kationenaustausch einen signifikanten Prozess für die Retardation organischer Kationen im Untergrund darstellt. Mit zwei kationischen Beta-Blockern durchgeführte Säulenversuche belegen die dominierende Rolle von Kationenaustauschprozessen. Steigende Konzentrationen anorganischer Kationen führen aufgrund der verstärkten Konkurrenz um die Austauscherplätze des Sorbens zu einer geringeren Sorption der organischen Kationen. Der Beitrag nicht-hydrophober Wechselwirkungen zur Gesamtsorption konnte mit >99% abgeschätzt werden. Aufgrund der großen Bedeutung von Kationenaustauschprozessen sollten weitere Einflussfaktoren berücksichtigt werden, um den Transport organischer Kationen zuverlässig vorhersagen zu können. Daher wurde anschließend der Einfluss konkurrierender anorganischer Kationen auf die Sorption organischer Kationen in Wasser/Sediment-Batchtests systematisch untersucht. Die bei verschiedenen Hintergrundkonzentrationen an anorganischen Kationen aufgenommenen Sorptionsisothermen des kationischen Beta-Blockers Metoprolol zeigten eine deutlich stärkere Beeinflussung der Sorption durch Ca2+ als durch Na+. Durch die gefundene Korrelation zwischen dem Freundlich-Koeffizienten und der Konzentration anorganischer Kationen wird eine Vorhersage der Metoprolol-Sorption im Bereich der untersuchten Randbedingungen möglich. Zudem konnte der Beitrag sorptiver Wechselwirkungen zum organischen Kohlenstoff des Sediments als vernachlässigbar bestimmt werden. Insgesamt liefern die erzielten Ergebnisse einen weiteren wichtigen Beitrag zur Prozessbeschreibung der Sorption und helfen somit, die Vorhersage des Stofftransportes organischer Kationen im Untergrund zu verbessern. Im letzten Teil der Arbeit werden das Konzept und die Entwicklung eines neuen, reaktiven Tracers (KIS-Tracer) zur Charakterisierung von Grenzflächen während Injektionen von überkritischem CO2 in tiefe salinare Aquifere beschrieben. Durch eine Hydrolysereaktion an der CO2/Wasser-Grenzfläche mit bekannter Kinetik wird ein Zusammenhang zur zeitlichen Änderung der Grenzflächengröße geschaffen. Basierend auf den vorangegangenen Untersuchungen zur Sorption, wurde das konservative, organische Anion Naphthalinsulfonat als Basisstruktur für die Tracersynthese (Veresterung) und somit auch als gewünschtes Hydrolyseprodukt ausgewählt. Neben der Definition notwendiger Tracereigenschaften wurden bereits erste Verbindungen synthetisiert, im Labor getestet und mit einem neuentwickelten, makroskopischen Modell ausgewertet. Abschließend wurde das Tracerverhalten exemplarisch für verschiedene hypothetische Funktionen der zeitlichen Grenzflächenänderung numerisch modelliert. Die bisher erzielten Ergebnisse sind sehr vielversprechend und gewähren einen ersten Einblick in das Potential von KIS-Tracern.

M.Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / In the present study, the removal of Ca2+ and Mg2+ from cooling tower water using Amberlite IR120 and Amberjet 1200 was studied by the application of one factor at a time method (OFAT) and response surface modelling (RSM). The effect of operational parameters such as contact time (min), pH, dosage (mL), concentration (mg/L) and temperature (K) were investigated using central composite design. The regeneration of the Amberlite IR120 and Amberjet were also studied. The purpose of the study was to apply OFAT and RSM to investigate and optimize the ion exchange operating parameters. Furthermore, the second-order empirical model that was developed, using the analysis of variance (ANOVA), presented a sufficient correlation to the ion exchange experimental data. The optimal ion exchange operating conditions for Amberlite IR120 and Amberjet 1200 were found to be: contact time was 120 min, dosage of 150mL, initial pH level of 2, concentration of 400mg/L and temperature of 343K. Regeneration of Amberlite IR120 and Amberjet 1200 using 0.5 M NaCl stripping solution initially showed an increase in % Ca2+ and Mg2+ removal, then a decrease in subsequent cycles. The correlation coefficients (R2) of Langmuir, Freudlich and Tempkin isotherms were found to range from 0.92 to 1 and this suggest that experimental data best described the models. However correlation coefficients (R2) for Dubinin–Radushkevich (D-R) model were found to range between 0.5 to 0.8 and this means that experimental data does not fit the model. Thermodynamic functions such as entropy (Δ𝑆𝑜), enthalpy (Δ𝐻𝑜) and change of free energy (Δ𝐺𝑜) were obtained from the gradient and intercepts of straight line graphs. The positive values of ΔG° were found meaning that the adsorption is not spontaneous and positive values of ΔH° were found meaning the endothermic type of adsorption which indicate the chances of physical adsorption.The correlation coefficient (R2) values of pseudo-first-order, pseudo-second-order and intraparticle models were found to range from 0.89 to 1 on both metals as shown in table 4.4. This observation clearly indicates that pseudo-first-order, pseudo-second-order and intraparticle diffusion models best describe the experimental data in the removal Ca2+ and Mg2+ from cooling tower water.

Robust ion-exchanged glass waveguides exhibit low optical losses in a broad spectral range and they allow integration of several devices on the same chip due to their planar structure. Consequently, they can be a low cost alternative to semiconductors for fabricating various integrated optical devices. Two high performance photonic devices were designed and realized, demonstrating the potential of glass waveguides. The well-controlled silver-film ion-exchange process allowed the fabrication of: i) a highly sensitive biosensor based on optical absorption and, ii) a low loss hybrid electro-optic (EO) polymer modulator with a narrow coplanar electrode gap. The single-mode, channel integrated optical ion-exchange waveguide on borosilicate glass (Corning 0211) is described for broad spectral band (400-650 nm) detection and analysis of heme-containing protein films at a glass/water interface. The evanescent wave interaction is improved significantly by fabricating ion-exchange waveguides with a step-like index profile. Silver nano-particle formation is reduced in order to achieve low loss in the Soret-band (~400 nm). Unlike other surface-specific techniques (e.g. SPR, interferometry) that probe local refractive-index changes and therefore are susceptible to temperature fluctuations, the integrated optical waveguide absorption technique probes molecular-specific transition bands and is expected to be less vulnerable to environmental perturbations. The hybrid integration of phosphate glass (IOG-1) and EO polymer is realized for the first time. The critical alignment steps which are typically required for hybrid optoelectronic devices are eliminated with a simple alignment-free fabrication technique. The low loss adiabatic transition from glass to EO polymer waveguide is enabled by gray scale patterning of the novel EO polymer, AJLY. Total insertion loss of 5 dB and electrode gap of 8 μm is obtained for an optimized device design. EO polymer poling at 135 ºC and 75 V/μm is enabled by the sol-gel buffer layer.

Solar photovoltaic modules provide clean electricity from sunlight but will not be able to compete on an open market until the cost of the electricity they produce is comparable to that produced by traditional methods. At present, modules based on crystalline silicon wafer solar cells account for nearly 90% of photovoltaic production capacity. However, it is anticipated that the ultimate cost reduction achievable for crystalline silicon solar cell production will be somewhat limited and that thin film solar cells may offer a cheaper alternative in the long term. The highest energy conversion efficiencies reported for thin film solar cells have been for devices based around chalcopyrite Cu(In, Ga)(Se, S)2 photovoltaic absorbers. The most efficient Cu(In, Ga)(Se, S)2 solar cells contain absorber layers deposited by vacuum co-evaporation of the elements. However, the cost of ownership of large area vacuum evaporation technology is high and may be a limiting factor in the cost reductions achievable for Cu(In, Ga)(Se, S)2 based solar cells. Therefore, many alternative deposition methods are under investigation. Despite almost thirty companies being in the process of commercialising these technologies there is no consensus as to which deposition method will lead to the most cost effective product. Non-vacuum deposition techniques involving powders and chemical solutions potentially offer significant reductions in the cost of Cu(In, Ga)(Se, S)2 absorber layer deposition as compared to their vacuum counterparts. A wide range of such approaches has been investigated for thirty years and the gap between the world record Cu(In, Ga)(Se, S)2 solar cell and the best devices containing non-vacuum deposited absorber layers has closed significantly in recent years. Nevertheless, no one technique has demonstrated its superiority and the best results are still achieved with some of the most complex approaches. The work presented here involved the development and investigation of a new process for performing one of the stages of non-vacuum deposition of Cu(In, Ga)(Se, S)2 absorber layers. The new process incorporates copper into an initial Group III-VI precursor layer, e.g. indium gallium selenide, through an ion exchange reaction performed in solution. The ion exchange reaction requires only very simple, low-cost equipment and proceeds at temperatures over 1000°C lower than required for the evaporation of Cu under vacuum. In the new process, indium (gallium) selenide initial precursor layers are immersed in solutions containing Cu ions. During immersion an exchange reaction occurs and Cu ions from the solution exchange places with Group III ions in the layer. This leads to the formation of an intimately bonded, laterally homogeneous copper selenide – indium (gallium) selenide modified precursor layer with the same morphology as the initial precursor. These modified precursor layers were converted to single phase chalcopyrite CuInSe2 and Cu(In, Ga)Se2 by annealing with Se in a tube furnace system. Investigation of the annealing treatment revealed that a series of phase transformations, beginning at low temperature, lead to chalcopyrite formation. Control of the timing of the Se supply was demonstrated to prevent reactions that were deemed detrimental to the morphology of the resulting chalcopyrite layers. When vacuum evaporated indium (gallium) selenide layers were used as initial precursors, solar cells produced from the absorber layers exhibited energy conversion efficiencies of up to 4%. While these results are considered promising, the devices were characterised by very low open circuit voltages and parallel resistances. Rapid thermal processing was applied to the modified precursor layers in an attempt to further improve their conversion into chalcopyrite material. Despite only a small number of solar cells being fabricated using rapid thermal processing, improvements in open circuit voltage of close to 150mV were achieved. However, due to increases in series resistance and reductions in current collection only small increases in solar cell efficiency were recorded. Rapid thermal processing was also used to demonstrate synthesis of single phase CuInS2 from modified precursor layers based on non-vacuum deposited indium sulphide. Non-vacuum deposition methods provide many opportunities for the incorporation of undesirable impurities into the deposited layers. Analysis of the precursor layers developed during this work revealed that alkali atoms from the complexant used in the ion exchange baths are incorporated into the precursor layers alongside the Cu. Alkali atoms exhibit pronounced electronic and structural effects on Cu(In, Ga)Se2 layers and are beneficial in low concentrations. However, excess alkali atoms are detrimental to Cu(In, Ga)Se2 solar cell performance and the problems encountered with cells produced here are consistent with the effects reported in the literature for excess alkali incorporation. It is therefore expected that further improvements in solar cell efficiency might be achieved following reformulation of the ion exchange bath chemistry.

Waste-to-energy has become an attractive alternative to landfills. One concern in this development is the release of pollutants in the combustion process. The binder enhanced d-RDF pellets satisfy the requirements of environmental acceptance, chemical/biological stability, and being storeable. The acid gas emissions of combusting d-RDF pellets with sulfur-rich coal were analyzed by ion chromatography and decreased when d-RDF pellets were utilized. The results imply the possibility of using d-RDF pellets to substitute for sulfur-rich coal as fuel, and also substantiate the effectiveness of a binder, calcium hydroxide, in decreasing emissions of SOx. In order to perform the analysis of the combustion sample, sampling and sample pretreatment methods prior to the IC analysis and the first derivative detection mode in IC are investigated as well. At least two trapping reagents are necessary for collecting acid gases: one for hydrogen halides, and the other for NOx and SOx. Factors affecting the absorption of acid gases are studied, and the strength of an oxidizing agent is the main factor affecting the collection of NOx and SOx. The absorption preference series of acid gases are determined and the absorption models of acid gases in trapping reagents are derived from the analytical results. To prevent the back-flushing of trapping reagents between impingers when leak-checking, a design for the sampling train is suggested, which can be adopted in sample collections. Several reducing agents are studied for pretreating the sample collected in alkali-permanganate media. Besides the recommendation of the hydrogen peroxide solution in EPA method, methanol and formic acid are worth considering as alternate reducing agents in the pretreatment of alkaline-permanganate media prior to IC analysis. The first derivative conductivity detection mode is developed and used in IC system. It is efficient for the detection and quantification of overlapping peaks as well as being applicable for non-overlapping peaks.

Master of Science / Department of Biology / Peter P. Wong / Abstract Water purification methods that remove pathogens and harmful or distasting molecules make water potable. Recently, silver loaded ion-exchange resins have demonstrated a strong role in removing microbes. The goal is to make an effective silver ion-based water purifier that is portable, environmentally stable, and cost efficient. The project was conducted as a collaborative effort with Safewater A/S, an up and coming entrepreneurial business located in Denmark that is interested in developing novel water purifiers for developing nations, adventurers and military personnel. Purolite, a prominent business in ion-exchange resins located in Whales, designed and provided Safewater A/S and our research team with experimental resins for water purification, which will be discussed in the body of this thesis. The data reveals critical issues that may render this tool unavailable for commercial production in some countries due to the mode of action for killing the bacteria and the amount of silver leaching. Tests were conducted using Escherichia coli K12 and Enterococcus faecalis OG1SSp as model fecal organisms using different silver ion-exchange resins. Surveillance of leached silver ions, pH changes, and total dissolved solids (TDS) were also monitored to find correlations with capacity (liters of purified water produced) and effectiveness of microbicidal action. Overall, one resin was found to contain properties consistent with the stated objectives; however its use in some countries as a water purifier for human consumption will be nullified due to extensive silver leaching. Although this resin could be used in the United States of America since it passes the Environmental Protection Agency (EPA) standards, Safewater A/S is interested in further developing it for countries with stricter regulatory constraints before mass production. The goal of the present thesis report is to address the stated objectives in the development of a water purifier.

The Matimba and soon to be completed Medupi power stations located in close proximity to the town of Lephalale are a cause for environmental concern due to the known effects that coal combustion has on air, soil and water quality. The Medupi power station is currently being constructed, while the Matimba power station may have already negatively altered the water quality of the rivers especially those downwind of the power stations. The Lephalala (perennial river, upwind), the Mokolo (perennial river, upwind) and Matlabas (seasonal river, downwind) Rivers were selected due to the locations relative to the power stations. The concentrations and flux of cations and sulphate ions within the rivers in the Waterberg District Municipality were investigated for any seasonal or annual patterns using monthly data from a single sampling station along each river. Data for the concentrations of sodium, potassium, magnesium, calcium, ammonium and sulphate were analysed in conjunction with river discharge, rainfall and ambient temperature data available for each hydrological year from 1999 to 2010. The data were converted to seasonal and annual values in order to determine the influence of the quality and quantity of coal combusted as well as climatic variables (rainfall, temperature and discharge) on ion fluxes measured. Sodium was the dominant cation in all rivers, reaching a maximum concentration of 0.0015 mol.ℓ-1 (in 2007), 0.0007 mol.ℓ-1 (in 2007) and 0.0006 mol.ℓ-1 (in 2001) in the Lephalala, Mokolo and Matlabas Rivers, respectively. Other cation concentrations were four times lower in the Lephalala and Mokolo Rivers, while they were eight times lower in the Matlabas Rivers. Sulphate concentrations were approximately nine, five and 15 times lower than the cation concentrations measured within the Lephalala, Mokolo and Matlabas Rivers, respectively. The mean summed cation flux was highest in the Lephalala River (0.0015 ± 0.0010 Eq.ℓ-1), which was approximately 1.7 and 2.1 times higher than summed cation fluxes measured in the Mokolo (0.0009 ± 0.0002 Eq.ℓ-1) and Matlabas (0.0007 ± 0.0006 Eq.ℓ-1) Rivers. Cation fluxes were highest during the rainfall season (summer and spring) in the river closest to the Matimba power station (Mokolo Rivers) while summed cation flux in the Lephalala and Mokolo Rivers (located further away from the power station) showed no specific seasonality. It was, however, noted that the cation fluxes during spring and winter were elevated for both rivers, possibly indicating

Este trabalho tem como objetivo otimizar as etapas da rota de purificação da glicerina bruta proveniente da produção de biodiesel, sendo elas, hidrólise ácida e retirada de sais através dos processos utilizando o efeito salting-out e troca iônica até obter uma solução aquosa de glicerol e etanol. Foi feito um planejamento fatorial 22 com dois pontos centrais tendo como variáveis de processo temperatura e tempo de reação, e como respostas o valor de pH da solução e a massa de glicerina separada, para cada ácido testado (ácido sulfúrico e ácido clorídrico). Para a glicerina hidrolisada com ácido sulfúrico o valor de pH não sofreu influência das variáveis do modelo. Para a massa de glicerina separada, houve efeito significativo positivo da temperatura e negativo do tempo. Para a hidrólise com ácido clorídrico, na análise do valor de pH há uma leve suspeita da influência negativa para o tempo, sem influência da temperatura. Para a massa há uma suspeita da influência negativa da temperatura, sem influência do tempo. Assim, as condições estabelecidas são de temperatura de 70 °C e tempo de reação de 180 minutos para a hidrólise com ácido sulfúrico e 50 °C e 180 minutos pra a hidrólise com ácido clorídrico. Na segunda etapa, que é a retirada de sais por salting-out, foi feito um planejamento de mistura com inclusão de variáveis de processo. Foram planejados 45 experimentos em um planejamento de mistura em função da composição dos alcoóis - etanol (x1), isopropanol (x2), n-butanol (x3) e das variáveis de processo pH e temperatura, obtendo os seguintes modelos: Massa_ retida = 1,44x1 + 0,99x2 + 0,77x3 + 0,13x1pH + 1,90x2x3. Analisando a equação, tratando-se dos álcoois puros pode-se observar que o etanol é mais eficiente na retenção de massa, pois apresenta o maior coeficiênte (1,44). A melhor interação é entre isopropanol e butanol. Quanto as variáveis de processo, o valor de pH teve uma leve influência quando se tratava da solução de etanol. Na análise da condutividade da glicerina filtrada foi obtido o seguinte modelo: Condutividade = 159,14x1 + 255,74x2 + 588,64x3 - 668,14x1x3 + 44,90x1pH - 42,57x1T - 596,79x2x3. Analisando a equação para soluções de alcoóis puros pode-se verificar que o menor coeficiente é para solução de etanol (159,14). Para misturas, etanol e n-butanol apresentam o menor coeficiente que isopropanol e n-butanol. Para soluções de etanol o pH e a temperatura mostram uma leve influência. Para o efeito salting-out definiu-se que seria mais vantajosa a utilização do etanol, pois facilita as etapas posteriores pela facilidade de evaporação e recuperação e baixo custo. Com essas análises ficaram definidas as melhores condições da glicerina em pH 5 e temperatura de 25 ºC, na presença de etanol. A troca iônica foi efetuada obtendo resultados satisfatórios em que a glicerina após passar pela troca iônica estava com condutividade inferior a 10 S/cm. / This work aims to optimize the stages of raw glycerin purification route from biodiesel production, which are, acid hydrolysis and salts extraction through salting out and ion exchange process until to achieve aqueous solution of glycerol and ethanol. A 22 factorial planning with two central points was carried out. Temperature and time reaction were the process variables and pH of solution and glycerin separated mass the answers for each acid tested (sulfuric acid and hydrochloric acid). The pH was not influenced by process variables for glycerin hydrolyzed with sulfuric acid. For separated glycerin mass the effect was positive for temperature and negative for time. For hydrolysis with hydrochloric acid, the pH analyses shows that there might be negative influence of time, and no influence of temperature. For separated glycerin mass there might be negative influence of temperature, and no influence of time. According to the experiments, when the glycerin was hydrolyzed with sulfuric acid the better reaction conditions occur at 70 °C and time reaction equal to 180 minutes. In the hydrolization with hydrochloric acid the conditions were 50 °C and time reaction 180 minutes. In the second stage, salt removal by salting-out effect, a mixture planning with process variables inclusion was conducted. 45 experiments in function of alcohol composition - ethanol (x1), isoprophanol (x2), n-buthanol (x3) and process variables pH and temperature were planned, obtaining the following model: Retained_mass = 1,44x1 + 0,99x2 + 0,77x3 + 0,13x1pH + 1,90x2x3. Analyzing the equation, treating only pure alcohols, it is possible to observe that ethanol is the most efficient in retaining mass due to its biggest coefficient (1,44). The best interaction occurs between butanol and isopropanol. When ethanol solution was used the pH influence can not be neglected. The analysis of the conductivity results the model bellow: Conductivity = 159,14x1 + 255,74x2 + 588,64x3 - 668,14x1x3 + 44,90x1pH - 42,57x1T - 596,79x2x3. Observing the equation, for pure alcohols solutions, ethanol has the smallest coefficient (159,14). For mixtures, ethanol and buthanol have smaller coefficient than isoprophanol and buthanol. For ethanol solutions, pH and temperature have little influence. For the salting-out process it was defined that would be more gainful with ethanol utilization, because it favours the next steps by faciliting evaporation and recover and its low cost. After these analyses satisfactory results for raw glycerin purification were obtained at pH 5 and 25°C, using pure ethanol. The glycerin purification by ion exchange process was carried out obtaining good results. The glycerin conductivity was less than 10 S/cm.

Nenhuma / A pesquisa consistiu no estudo de recuperação do zinco e metais associados presentes no efluente do processo industrial, como também na reciclagem da água para o processo produtivo da Votorantin Metais Unidade Juiz de Fora, empregando-se o processo de adsorção por troca iônica, visando obter condições operacionais que viabilizasse a implantação do sistema. Os principais constituintes do efluente estudado são: Zn, Ca, Mg, Mn, Cd, Cu e Pb. A investigação realizada, se aplicada ao processo industrial, possibilita a reciclagem de alguns destes metais, tais como: Zn, Cd, Cu e Pb. Os demais metais podem ser removidos do sistema viabilizando a reutilização da água, atualmente descartada. Para a recuperação dos metais foi utilizado o processo de adsorção com trocadores iônicos, tendo sido empregadas resinas de troca iônica, zeólitas e outros adsorventes naturais, que geralmente são empregados em soluções que contenham baixas concentrações de metais, tal como a amostra investigada. A amostra foi coletada na bacia de equalização, local este que recebe todo efluente da planta industrial para tratamento final e posterior descarte no corpo receptor. / The research consisted of the study of recovery of zinc and metals associates present in the effluent of the industrial process of the Votorantin Metais, Juiz de Fora Unit. The main constituent of the shedied effluent are: Zn, Ca, Mg, Mn, Cd, Cu and Pb. The experimental work, if applied to the industrial process, will enable the recovery of some of these metals, such as: Zn, Cd, Cu and Pb. The metals can be removed from the system enabling the recicling of the water curretly discarded. This research was developed considering the conditions that enabled tha set up of the system. For metals recovery it was used the adsorption process with ionic exchangers, such as exchange zeolites and other natural adsorbents. These materials are generally used in solutions that contain low metal concentrations, as the investigated sample. This sample was collected in the Bacia de Equalização where all effluentes generated in the industrial plant are sent and the final treatment befor discarding is made.