Happaman hydrometallurgisen PLS-liuoksen puhdistaminen kiintoaineesta kalvosuodatustekniikalla

Tässä diplomityössä tutkittiin keraamisten mikrosuodatuskalvojen soveltuvuutta kiintoaineen erottamiseen happamasta PLS-liuoksesta eri huokoskoon omaavilla mikrosuodatuskalvoilla. Koelaitteistolla suodatettiin puhdasta vettä, kaoliinipitoista vesiliuosta sekä hapanta kuparia, kalsiumia ja kaoliinia sisältävää malliliuosta. Koeajojen tavoitteena oli saada tietoa permeaattivuon maksimimäärästä eri mikrosuodatuskalvoilla sekä tuotteen puhtaudesta. Näiden lisäksi saatiin tietoa kalvojen likaantumisesta ajon aikana. Teoriaosassa käsiteltiin yleisesti kalvosuodatusta, esitettiin yleiset kalvotekniset menetelmät ja sovellukset sekä käytiin läpi tutkimuksia samankaltaisiin kalvoihin ja sovelluksiin liittyen. Lisäksi teoriaosuudessa pohdittiin mahdollisuutta käyttää myös muita, kuin putkimoduulisia mikrosuodatuskalvoja. Myös työhön oleellisena taustana kuuluvaa hydrometallurgiaa tarkasteltiin teoreettiselta kannalta. Puhtaan veden suodatuskoetuloksista havaittiin, että kaikki kalvot jäivät selvästi valmistajan ilmoittamista arvoista. 1,0 µm CoMetas CoMem® kalvon teoreettinen vesivuo on 10 m3/(h bar) ja 3,0 µm CoMetas CoMem® teoreettinen vesivuo on yli 50 m3/(h bar). Näistä parhaimman vuon arvon sai 1,0 µm CoMetas CoMem® mikrosuodatuskalvo. Tämä kalvo oli paras sekä veden suodatuksissa että malliliuoksella tehdyillä suodatuksilla. Malliliuoksella saavutettiin n. 2000 L/(m2 h) paineen ollessa 2,0 bar ja virtausnopeuden ollessa 4,4 m/s. Vastaavat vesiajon tulokset olivat n. 1100 L/(m2 h) paineen ollessa 1,0 bar ja virtausnopeuden 2,9 m/s. Kaikki kolme käytettyä kalvoa pidättivät kaoliiniliuoksen 81–100 %:sesti. Kuparipitoista malliliuosta suodatettaessa pystyttiin vastaavasti erottamaan 77–99 % kiintoaineesta. Koeajoissa kuitenkin havaittiin huomattava vuon arvojen putoaminen, joka johtui kalvon likaantumisesta. Huomioitavaa oli kuitenkin, että hapanta malliliuosta suodatettaessa permeaattivuon arvot olivat kaoliiniliuoksen suodatuksessa saatuja vastaavia arvoja korkeammat.

Free PAPP-A: a Novel Marker in Acute Coronary Syndrome Patients

In recent years, one important objective of cardiovascular research has been to find new markers that would improve the risk stratification and diagnosis of patients presenting with symptoms of acute coronary syndrome (ACS). Pregnancy-associated plasma protein A (PAPP-A) is a large metalloproteinase involved in insulin-like growth factor signalling. It is expressed in various tissues and seems to be involved in many physiological and pathological processes, such as folliculogenesis, bone formation, wound healing, pregnancy and atherosclerosis. The aim of this thesis was to investigate PAPP-A in ACS patients. Circulating concentrations of PAPP-A had been previously shown to be elevated in ACS. In this study it was revealed that the form of PAPP-A causing this elevation was the free noncomplexed PAPP-A. Thus, the form of PAPP-A in the circulation of ACS patients differed from the complexed PAPP-A form abundantly present in the circulation during pregnancy. A point-of-care method based on time-resolved immunofluorometric assays was developed, which enabled the rapid detection of free PAPP-A. The method was found to perform well with serum and heparin plasma samples as well as with heparinized whole blood samples. With this method the concentrations of free PAPP-A in healthy individuals were shown to be negligible. When the clinical performance of the method was evaluated with serum samples from ACS patients, it was shown that the free PAPP-A concentration in the admission sample was an independent predictor of myocardial infarction and death. Moreover, as a prognostic marker, free PAPP-A was revealed to be superior to total PAPPA, i.e. the combination of free and complexed PAPP-A, which has been measured by the other groups in this field. As heparin products are widely used as medication in ACS patients, the effect of heparin products on free PAPP-A molecule and circulating concentrations were also investigated in this study. It was shown that intravenous administration of low molecular weight or unfractionated heparin elicits a rapid release of free PAPP-A into the circulation in haemodialysis patients and patients undergoing angiography. Moreover, the interaction between PAPP-A and heparin was confirmed in gel filtration studies. Importantly, the patients included in the clinical evaluation of the free PAPP-A detection method developed had not received any heparin product medication before the admission sample and thus the results were not affected by the heparin effect. In conclusion, free PAPP-A was identified as a novel marker associated with ACS. The point-of-care methods developed enable rapid detection of this molecule which predicts adverse outcome when measured in the admission sample of ACS patients. However, the effect revealed of heparin products on circulating PAPP-A concentrations should be acknowledged when further studies are conducted related to free or total PAPP-A in ACS.

Treatment of oily wastewater by ultrafiltration: The effect of different operating and solution conditions

In many industries, such as petroleum production, and the petrochemical, metal, food and cosmetics industries, wastewaters containing an emulsion of oil in water are often produced. The emulsions consist of water (up to 90%), oils (mineral, animal, vegetable and synthetic), surfactants and other contaminates. In view of its toxic nature and its deleterious effects on the surrounding environment (soil, water) such wastewater needs to be treated before release into natural water ways. Membrane-based processes have successfully been applied in industrial applications and are considered as possible candidates for the treatment of oily wastewaters. Easy operation, lower cost, and in some cases, the ability to reduce contaminants below existing pollution limits are the main advantages of these systems. The main drawback of membranes is flux decline due tofouling and concentration polarisation. The complexity of oil-containing systems demands complementary studies on issues related to the mitigation of fouling and concentration polarisation in membranebased ultrafiltration. In this thesis the effect of different operating conditions (factors) on ultrafiltration of oily water is studied. Important factors are normally correlated and, therefore, their effect should be studied simultaneously. This work uses a novel approach to study different operating conditions, like pressure, flow velocity, and temperature, and solution properties, like oil concentration (cutting oil, diesel, kerosene), pH, and salt concentration (CaCl2 and NaCl)) in the ultrafiltration of oily water, simultaneously and in a systematic way using an experimental design approach. A hypothesis is developed to describe the interaction between the oil drops, salt and the membrane surface. The optimum conditions for ultrafiltration and the contribution of each factor in the ultrafiltration of oily water are evaluated. It is found that the effect on permeate flux of the various factors studied strongly depended on the type of oil, the type of membrane and the amount of salts. The thesis demonstrates that a system containing oil is very complex, and that fouling and flux decline can be observed even at very low pressures. This means that only the weak form of the critical flux exists for such systems. The cleaning of the fouled membranes and the influence of different parameters (flow velocity, temperature, time, pressure, and chemical concentration (SDS, NaOH)) were evaluated in this study. It was observed that fouling, and consequently cleaning, behaved differently for the studied membranes. Of the membranes studied, the membrane with the lowest propensity for fouling and the most easily cleaned was the regenerated cellulose membrane (C100H). In order to get more information about the interaction between the membrane and the components of the emulsion, a streaming potential study was performed on the membrane. The experiments were carried out at different pH and oil concentration. It was seen that oily water changed the surface charge of the membrane significantly. The surface charge and the streaming potential during different stages of filtration were measured and analysed being a new method for fouling of oil in this thesis. The surface charge varied in different stages of filtration. It was found that the surface charge of a cleaned membrane was not the same as initially; however, the permeability was equal to that of a virgin membrane. The effect of filtration mode was studied by performing the filtration in both cross-flow and deadend mode. The effect of salt on performance was considered in both studies. It was found that salt decreased the permeate flux even at low concentration. To test the effect of hydrophilicity change, the commercial membranes used in this thesis were modified by grafting (PNIPAAm) on their surfaces. A new technique (corona treatment) was used for this modification. The effect of modification on permeate flux and retention was evaluated. The modified membranes changed their pore size around 33oC resulting in different retention and permeability. The obtained results in this thesis can be applied to optimise the operation of a membrane plant under normal or shock conditions or to modify the process such that it becomes more efficient or effective.

Purificação e caracterização de uma gentioexaose obtida de botriosferana por hidrólise ácida parcial

A hexa-oligosaccharide was obtained by partial acid hydrolysis from botryosphaeran, an exopolysaccharide (EPS) β(1→3; 1→6)-D-glucan type, produced by the ascomyceteous fungus Botryosphaeria rhodina. The oligosaccharide was purified by gel filtration and charcoal-Celite column chromatography and the analysis was followed by HPAEC/PAD. The structure was determined by NMR spectroscopy and mass spectrometry, which showed that the oligosaccharide consists of six β-D-glucopiranosyl units O-6 substituted (gentiohexaose).

Propriedades redox da matéria orgânica isolada de material ultrafiltrado das águas do rio Paraíba do Sul

Previous studies indicated that free radicals control organic matter redox activities. In the present study, organic matter of an ultra-filtrated material collected from seven samples taken seasonally from the Paraiba do Sul River for two years were titrated with an oxidizer (I2) in an inert atmosphere. Standard formal potential values for the electrode MO Ox, MO Red ranged from 0.754 to 0.786 V at a 25 ºC temperature. Organic matter oxidation capacity (COx) per carbon mass varied according to pH values, and changes in COx were related to rainfall and river flow intensities.

Influência das características das substâncias húmicas aquáticas na eficiência da coagulação com o cloreto férrico

The aim of this study was to verify the influence of the apparent molecular size of aquatic humic substances on the effectiveness of coagulation with ferric chloride. Coagulation-filtration tests using jar test and bench-scale sand filters were carried out on samples of water with true color of approximately 100 Hazen units, prepared with aquatic humic substances of different molecular sizes (F1: < 0.45 µm, F2: 100 kDa - 0.45 µm, F3: 30 - 100 kDa and F4': < 30 kDa). For the water samples with lower apparent molecular size fractions, greater dosages of coagulant was needed to remove the color around 5.0 Hanzen units, mainly because these water samples contain higher concentrations of fulvic acids, which exhibited a larger number of negatively-charged groups.

Development of new dissolution test and HPLC-RP method for anti-parasitic ornidazole coated tablets

This work aimed the development and validation of a new dissolution test for ornidazole coated tablets. The dissolution conditions were determined after testing Sink conditions, dissolution medium, apparatus, stirring speed, 24 h stability and medium filtration influence. The best conditions were paddle at a stirring speed of 75 rpm and 900 mL of 0.1 M HCl. A new HPLC quantification method was developed and validated. The dissolution test and quantification method showed to be adequate for their purposes and could be applied for quality control of ornidazole coated tablets, since there is no official monograph.

Otimização e validação de método para determinação de ácidos orgânicos em vinhos por cromatografia líquida de alta eficiência

The organic acids (tartaric, malic, citric, lactic and succinic) are de main components responsible for the acidity in the wine. This method for simultaneous determination of organic acids and interfering peaks in wines can be achieved in 16 min. The sample preceded by a dilution and filtration step. The chromatographic separation required one reversed phase column, isocratic mobile phase (acetonitrila, formic acid in water) and detection wavelength was set at 212 nm. The validation confirmed good repeatability, recovery and application in red and white wines.

Evaluation of sample processing methods for the polar contaminant analysis of sewage sludge using liquid chromatography - mass spectrometry (LC/MS)

Monitoring of sewage sludge has proved the presence of many polar anthropogenic pollutants since LC/MS techniques came into routine use. While advanced techniques may improve characterizations, flawed sample processing procedures, however, may disturb or disguise the presence and fate of many target compounds present in this type of complex matrix before analytical process starts. Freeze-drying or oven-drying, in combination with centrifugation or filtration as sample processing techniques were performed followed by visual pattern recognition of target compounds for assessment of pretreatment processes. The results shown that oven-drying affected the sludge characterization, while freeze-drying led to less analytical misinterpretations.

Purificação e caracterização da quitinase de uva (Vitis vinífera L. cv Red Globe) para a produção de quitosana a partir de quitina de camarão

Chitinase is produced by a wide variety of plants as a defense against peste attacks. In this study, grape chitinases were purified 16 times by fractionation in 80% ammonium sulfate followed by dialysis and filtration. Purified chitinases exhibited enzymatic activity toward chitin azure. The yield of purified chitinase was 229 mg/L with chitinase activity of 563 U/g. Chitinases had molecular masses of 24 and 30 kDa, as evaluated by SDS-PAGE 12.5%. Two pH optima were determined 3.0 and 6.0. The optimal temperature was 42 °C. Pre hydrolysis of crystalline shrimp chitin by chitinases caused in an increase in the deacetylation ratio triggered by chitin deacetylase producing chitooligosaccharides with DA (degree acetylation) of 58.8%.

Metodologias para reutilização do resíduo de terra diatomácea, proveniente da filtração e clarificação da cerveja

The earth diatomite is a material used by the industries in the filtration process and clarification of the beer. This material presents a reduced useful life due to the blockages of their pores during the filtration process. The objective of this work was to reactivate the properties of filtration of the earth diatomite, saturated with organic matter during the filtration stage, starting from a controlled thermal treatment. The obtained results demonstrated that the earth diatomite saturated with organic matter submitted to a controlled thermal treatment has their filtration properties reactivated, could be reused in the beer production process.

Produção e caracterização de espumas cerâmicas obtidas a partir de lodo de anodização de alumínio

Ceramic foams were produced from a sludge generated in the aluminum anodizing process by using an industrial polyurethane foam (replication method) with open cell sizes of 10 ± 5 ppi (porosity = 97%) which were impregnated with suspensions containing 50-61 wt.% alumina, 1 wt.% citric acid, 6 wt.% bentonite and fired at 1600 ºC for 2 h. The aluminum anodizing sludge shows a high alumina content (87.5 wt.%) and a low particle size (~1.7 mm) after calcination and milling. The obtained filters show porosity of approximately 70%, filtration capability (mass water flow) of 1.7 kg/s and mechanical strength under compression of 2.40 MPa.

Recuperação de compostos de iodo de reagentes e soluções laboratoriais

This work presents simple routes to recover iodine compounds from oxidized laboratory chemicals and aqueous solutions (HI and KI) used in laboratory chemistry classes. These routes are based on the oxidation of iodide ions (I-) to iodine (I2) by an oxidant (H2O2) or reduction of oxidized iodine by red phosphorus or hydrazine. Both routes presented high yields. The oxidative route is of general use whereas the reductive one is appropriate for restoring original iodine reagents. Final wastes were generated in low amounts. This work is appropriate for teaching many laboratory techniques (e.g., distillation, titration and filtration) in the chemical laboratory.

Considerações sobre o preparo de amostras contendo micropoluentes estrogênicos

In this work, the materials used in the recovery of estrogens from aqueous matrices by filtration and solid phase extraction were evaluated. The results showed that glass-fiber filters allow a recovery and repeatability compatible with this type of analysis, whereas cellulose esters lead to significant losses of the analytes, mainly due to adsorption processes. On the other hand, the transferring of the sample to the extraction cartridges should be carried out with glass or Teflon tubing, since the adsorption observed with other polymeric materials (eg. silicone, Tygon, polyethylene and PVC) dramatically reduces the recovery and repeatability of the extraction process.

Impregnação do ácido 12-fosfotúngstico em sílica - parte I: determinação de parâmetros de impregnação, caracterização e avaliação da atividade catalítica

Catalyst based on Kegging-type heteropolyacids (H3PW12O40 - HPA), supported on SiO2 (H3PW), were prepared by the impregnation method under different thermal treatment conditions. The materials were characterized by different instrumental techniques and used as catalysts in the methyl esterification reactions of stearic acid. Using the catalyst with 15% of HPA, conversions higher than 60% were obtained after 2 h of reaction at 65 ºC. Recovery studies using hot-filtration with ethanol at 75 ºC showed satisfactory activity for two additional reaction cycles.