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Dissertations / Theses on the topic 'Pharmaceutical Adsorption'
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Huang, Tongtong. "Protein adsorption and denaturation in injectable devices for pharmaceutical applications." Thesis, Mulhouse, 2016. http://www.theses.fr/2016MULH8373.
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Protéines sont largement utilisés dans la formulation dans le domaine pharmaceutique et de jouer un rôle important dans les fonctions biologiques. Il est bien connu que l'adsorption de protéines sur la surface solide est toujours observé pour un stockage à long terme, ce qui entraînera une réduction de la dose de substance active ou une perte de l'activité biologique. Dans certains cas, une courte période de contact avec la surface est suffisante pour modifier fortement la conformation des protéines : par exemple, l'insuline pertes 52% de son activité biologique après 5 minutes de contact avec la surface de verre, ainsi qu'une perte de 30% d’activité biologique du cétrorélix est observé après 2 heures de contact. Parmi tous les paramètres, la dénaturation des protéines est fortement liée à sa stabilité des propriétés de surface. La compréhension de l'adsorption de protéines est devenue une question cruciale dans l'industrie pharmaceutique.Pour mieux comprendre le comportement des protéines à la surface, la quantification des protéines adsorbées et sa conformation devrait être étudiée. L'objectif de notre recherche sera de comprendre les comportements des protéines sur différents surfaces de seringue pré - remplie classique.Le principal objectif de ce projet est de comprendre le comportement de plusieurs modèles de protéines comme la sérum d’albumine bovine (BSA), le lysozyme (LSZ) et la myoglobine (MGB) en contact avec des surfaces de seringues pré-remplie comme le verre et l’élastomère. Nous proposons d'utiliser la chromatographie liquide à haute performance (HPLC) pour la quantification de protéine adsorbée sur une surface plane en déterminant la déplétion des protéines en solution. La réflexion totale atténuée infrarouge à transformée de fourier (FTIR-ATR) spectroscopie est utilisée de suivre les changements structurels des protéines adsorbées sur des surfaces solides. [...]Proteins are widely used in formulation in the pharmaceutical field and play a major role in biological functions. It is well known that protein adsorption on solid surface is always observed for a long-term storage, which will result in a reduced dose of active compound or a loss of biological activity. In some cases, only short time of contact are sufficient to drastically modify the protein conformation: for instance, insulin losses 52% of its biological activity after 5 minutes contacting with glass surface, as well as a loss of 30% of cetrorelix is observed after 2 hours. Among all parameters, the time frame of the denaturation process is strongly related to the protein stability and surface properties. The understanding of protein adsorption has therefore become a crucial issue in the pharmaceutical industry.To gain a better understanding of proteins’ behavior on the surface, adsorbed protein quantification and its conformation should be studied. The objective of our research in a first will be to understand proteins’ behaviors on various surfaces which composed a classical prefilled syringe.The main goal of this PhD project is to understand the behaviors of several model proteins like bovine serum albumin (BSA), lysozyme (LSZ) and myoglobin (MGB) in contact with the surfaces of prefilled syringes such as glass and elastomer. We propose to use the high performance liquid chromatography (HPLC) to quantify the amount of protein adsorbed on a flat surface by determining the depletion of the proteins in solution. Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy was as well as employed to follow the structural changes of adsorbed BSA on solid surface. [...]
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Carthew, David Leonard. "Physico-chemical properties of poloxamer surfactants related to adsorption." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243418.
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Armstrong, Trevor Ian. "Protein adsorption onto polymeric nanoparticles : its relevance to drug targeting." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284047.
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Vutukuru, Naresh Kumar Reddy. "Apparent dissolution rate enhancement of poorly-water soluble drugs by adsorption technique." Scholarly Commons, 2015. https://scholarlycommons.pacific.edu/uop_etds/269.
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Nearly 70% of the new chemical entities (NCE’s) discovered are poorly-water soluble drugs and the number of poorly-water soluble drugs are increasing rapidly in the drug discovery. Most of the NCE’s are lipophilic and have dissolution rate issues. Low dissolution rate of the drugs result in poor bioavailability. To overcome poor bioavailability, an adsorption technique is developed to enhance the apparent dissolution rate of poorly-water soluble drugs. In this study, two poor-water soluble model drugs, ibuprofen and carvedilol were used. Methanol, DMF, DMSO and PEG400 were used as solvents and microcrystalline cellulose was used as an adsorbent. Pure model drugs, physical mixtures and prepared composites were characterized by using FTIR, DSC, XRD and dissolution testing. Results showed that the composites prepared with solvents DMF, DMSO and PEG400 showed enhancement in dissolution rates of two model drugs. Characterization of the composites prepared by using non-volatile solvents showed successful conversion of crystalline model drugs into solution state. Whereas, composites prepared by using volatile solvent showed similar results like physical mixtures and pure drug. Ibuprofen composites containing DMF, DMSO and PEG400 showed 9.4, 7.4 and 1.8 folds of increase in apparent dissolution rate, respectively. Whereas carvedilol composites containing DMF and DMSO showed 11.52 and 3.4 folds of increase in apparent dissolution rate. Four months of stability study were conducted on prepared composites at both 40°C and room temperature. It was observed that prepared composites were stable after 4 months and exhibited similar dissolution rate. In conclusion, the use of non-volatile solvents disrupted the crystal structure but also retained the drug in solution state which in turn enhanced the apparent dissolution rate of model drugs used. From the observed results we conclude that this method has a potential to replace existing techniques to enhance the apparent dissolution rate of the drug and stability of the composites.
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Machado, Ana Isabel de Oliveira. "Removal of pharmaceutical active compounds by constructed wetland systems - a sustainable phytoremediation technique?" Doctoral thesis, ISA, 2020. http://hdl.handle.net/10400.5/21195.
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Doutoramento em Restauro e Gestão Fluviais - Instituto Superior de Agronomia. Universidade de LisboaEmergent pollutants such as pharmaceutical active compounds (PhACs) have gained attention in the recent years since they can pose a threat to both river ecosystems and human health. The wide variety of pollutants in the market nowadays has overburdened the current wastewater treatment plants (WWTPs). Moreover, due to the increasingly growing society ecological awareness, environment friendly technologies have been more recently explored for wastewater treatment. Constructed wetlands (CWs) systems are an attractive example since they mimic natural processes such as pollutants filtration, phytoremediation and biodegradation but in a controlled form. The present thesis explore the potential of using locally available industry by products and native riparian wetland plants for enhancing the performance and implementation of CWs, for the removal of the highly consumed diuretic drug Furosemide. The state of art on the thesis subject was elaborated taking into account the situation in Portugal and in Brazil. Afterwards the validation of an analytical Furosemide quantification method through high performance liquid chromatography (HPLC-UV) in aqueous solution was performed taking in consideration the thesis projected experiments design. Light expanded clay aggregates and cork granulates were tested in terms of Furosemide adsorption capacity, showing both good removal values although with different adsorption ratio behaviours. A plant uptake experiment was performed with Iris pseudacorus to develop an analytical quantification method through HPLC-MS/MS for Furosemide in plant tissues. The PhAC was detected in the plants at residual concentrations hence limiting plant uptake capacity conclusions. Additionally, an experiment with both Iris pseudacorus and Typha domingensis was performed to study their uptake capacity, having both promoted similar removals of the PhAC. In overall, the tested components showed potential for CWs application and enhancement
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Ali, Shazia. "The adsorption characteristics of the poloxamer surfactants on model hydrophic drugs in suspension systems." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272211.
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Åsberg, Dennis. "Fundamental and Regulatory Aspects of UHPLC in Pharmaceutical Analysis." Doctoral thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-47852.
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Ultra-high performance liquid chromatography (UHPLC) provides a considerable increase in throughput compared to HPLC and a reduced solvent consumption. The implementation of UHPLC in pharmaceutical analysis, e.g. quality control, has accelerated in recent years and there is currently a mix of HPLC and UHPLC instrumentation within pharmaceutical companies. There are, however, technical and regulatory challenges converting a HPLC method to UHPLC making it difficult to take full advantage of UHPLC in regulatory-focused applications like quality control in pharmaceutical production. Using chromatographic modelling and fundamental theory, this thesis investigated method conversion between HPLC and UHPLC. It reports on the influence of temperature gradients due to viscous heating, pressure effects and stationary phase properties on the separation performance. It also presents a regulatory concept for less regulatory interaction for minor changes to approved methods to support efficient life cycle management. The higher pressure in UHPLC gave a retention increase of up to 40% as compared to conventional HPLC while viscous heating, instead, reduced retention and the net result was very solute dependent. Selectivity shifts were observed even between solutes with similar structure when switching between HPLC and UHPLC and an experimental method to predict such selectivity shifts was therefore developed. The peak shape was negatively affected by the increase in pressure for some solutes since secondary interactions between the solute and the stationary phase increased with pressure. With the upcoming ICH Q12 guideline, it will be possible for the industry to convert existing methods to UHPLC in a more flexible way using the deeper understanding and the regulatory concept presented here as a case example.Ultra-high performance liquid chromatography (UHPLC) provides a considerable increase in throughput compared to conventional HPLC and a reduced solvent consumption. The implementation of UHPLC in pharmaceutical analysis has accelerated in recent years and currently both instruments are used. There are, however, technical and regulatory challenges converting a HPLC method to UHPLC making it difficult to take full advantage of UHPLC in regulatory-focused applications like quality control in pharmaceutical production. In UHPLC, the column is packed with smaller particles than in HPLC resulting in higher pressure and viscous heating. Both the higher pressure and the higher temperature may cause changes in retention and selectivity making method conversion unpredictable. Using chromatographic modelling and fundamental theory, this thesis investigates method conversion between HPLC and UHPLC. It reports on the influence of temperature gradients due to viscous heating, pressure effects and stationary phase properties on the separation performance. It also presents a regulatory concept for less regulatory interaction for minor changes to approved quality control methods and how predicable method conversion is achieved by improved understanding.
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Gupta, Patel Salin. "MECHANISMS AND THERMODYNAMICS OF THE INFLUENCE OF SOLUTION-STATE INTERACTIONS BETWEEN HPMC AND SURFACTANTS ON MIXED ADSORPTION ONTO MODEL NANOPARTICLES." UKnowledge, 2019. https://uknowledge.uky.edu/pharmacy_etds/103.
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Nanoparticulate drug delivery systems (NDDS) such as nanocrystals, nanosuspensions, solid-lipid nanoparticles often formulated for the bioavailability enhancement of poorly soluble drug candidates are stabilized by a mixture of excipients including surfactants and polymers. Most literature studies have focused on the interaction of excipients with the NDDS surfaces while ignoring the interaction of excipients in solution and the extent to which the solution-state interactions influence the affinity and capacity of adsorption. Mechanisms by which excipients stabilize NDDS and how this information can be utilized by formulators a priori to make a rational selection of excipients is not known.
The goals of this dissertation work were (a) to determine the energetics of interactions between HPMC and model surfactants and the extent to which these solution-state interactions modulate the adsorption of these excipients onto solid surfaces, (b) to determine and characterize the structures of various aggregate species formed by the interaction between hydroxypropyl methylcellulose (HPMC) and model surfactants (nonionic and ionic) in solution-state, and (c) to extend these quantitative relationships to interpret probable mechanisms of mixed adsorption of excipients onto the model NDDS surface.
A unique approach utilizing fluorescence, solution calorimetry and adsorption isotherms was applied to tease apart the effect of solution state interactions of polymer and surfactant on the extent of simultaneous adsorption of the two excipients on a model surface. The onset of aggregation and changes in aggregate structures were quantified by a fluorescence probe approach with successive addition of surfactant. In the presence of HPMC, the structures of the aggregates formed were much smaller with an aggregation number (Nagg) of 34 as compared to micelles (Nagg ~ 68) formed in the absence of HPMC. The strength of polymer-surfactant interactions was determined to be a function of ionic strength and hydrophobicity of surfactant. The nature of these structures was characterized using their solubilization power for a hydrophobic probe molecule. This was determined to be approximately 35% higher in the polymer-surfactant aggregates as compared to micelles alone and was attributed to a significant increase in the number of aggregates formed and the increased hydrophobic microenvironment within these aggregates at a given concentration of surfactant.
The energetics of the adsorption of SDS, HPMC, and SDS-HPMC aggregate onto nanosuspensions of silica, which is the model solid surface were quantified. A strong adsorption enthalpy of 1.25 kJ/mol was determined for SDS adsorption onto silica in the presence of HPMC as compared to the negligible adsorption enthalpy of 0.1 kJ/mol for SDS alone on the silica surface. The solution depletion and HPMC/ELSD methods showed a marked increase in the adsorption of SDS onto silica in the presence of HPMC. However, at high SDS concentrations, a significant decrease in the adsorbed amount of HPMC onto silica was determined. This was further corroborated by the adsorption enthalpy that showed that the silica-HPMC-SDS aggregation process became less endothermic upon addition of SDS. This suggested that the decrease in adsorption of HPMC onto silica at high SDS concentrations was due to competitive adsorption of SDS-HPMC aggregates wherein SDS is displaced/desorbed from silica in the presence of HPMC. At low SDS concentrations, an increase in adsorption of SDS was due to cooperative adsorption wherein SDS is preferentially adsorbed onto silica in the presence of HPMC. This adsorption behavior confirmed the hypothesis that the solution-state interactions between pharmaceutical excipients such as polymers and surfactants would significantly impact the affinity and capacity of adsorption of these excipients on NDDS surfaces.
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Wiser, Lauren Sample. "Mechanisms of polymer adsorption in nanoparticle stabilization for poorly water soluble compounds." Scholarly Commons, 2011. https://scholarlycommons.pacific.edu/uop_etds/159.
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In this dissertation, the mechanisms of nanosuspension stabilization via polymer adsorption on nanoparticle surface were investigated. As the electrokinetic behavior and colloidal stability depend on the surface characteristics, altering the surface adsorbed polymers affords the different surface properties of nanoparticles and leads to the insight on the mechanism of nanoparticle stabilization. Drug nanosuspensions were prepared by wet milling of drug with water as medium and polymers as stabilizers. Block copolymers were evaluated based on varying the hydrophobic and hydrophilic amounts, polymer concentration, and polymer affinity differences onto the nanoparticle surface. Specifically, block copolymers of ethylene oxide (EO) and propylene oxide (PO) with different EO chain lengths were used to modify the nanoparticle surface and investigate the mechanisms of stabilization by varying the ratio of hydrophobic (PO) and hydrophilic (EO) units. It was hypothesized that the PO chain of block copolymers adsorb at the solid-solution interface and the EO chain provides steric hindrance preventing aggregation. Block copolymer adsorption layer thicknesses were experimentally determined with adsorption layer thicknesses increasing from 4.7 to 9.5 nm as the number of EO increase from 26 to 133 monomer units. Nanoparticle aggregation occurred with insufficient polymer monolayer coverage and electrokinetic zeta potential greater than -20 mV. The amount of block copolymers on the surface of nanoparticles was quantified and the affinity of polymer adsorption increased as the copolymer hydrophobic units increased. The amount adsorbed and affinity provides a qualitative ranking of the affinities between a specific polymer and nanoparticle substrate to provide a method in determining the mechanism of stabilization, where specific functional groups for adsorption could be selected for maximum nanoparticle stability. A molecular modeling was conducted to visualize and support the mathematical model and the proposed mechanism of block copolymer adsorption onto a nanoparticle surface. The time lapse molecular modeling of a block copolymer in an aqueous media showed the hydrophobic units adsorbing onto the nanoparticle surface with the hydrophilic units projecting into the aqueous media. For the first time in pharmaceutical research, a systematic series of studies were conducted to elucidate the mechanisms of adsorption with both surface charge and polymer affinity analyses. A series of studies evaluating the adsorption properties polymer stabilizers provided useful information on how a block copolymer comprised of both hydrophilic and hydrophobic domains adsorbs onto an active pharmaceutical ingredient. A systematic set of experimental techniques were presented with novel analysis tools and predictors to construct stable nanoparticle formulations.
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Buyuktimkin, Tuba. "The influence of the adsorption of metoclopramide and related benzamides on the ionization of the silica surface." Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/2676.
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The drug metoclopramide was found to adsorb to the unionized and ionized silica surface. The primary objective of this research was to use potentiometric titration in order to study the specificity of the interactions of benzamide analogs with the hydroxyl groups, silanols, on the Aeroperl® silica surface.
Mass titration studies showed that the acidity of surface silanols increases with dissolved metoclopramide and similar compounds. The nature of the interaction was concluded to involve a physical adsorption process. A different potentiometric titration method was devised to determine the ionization of silanols in the presence of a dissolved compound with solubility limitations. This method was found to give similar results as that described in the literature. The presence of dissolved metoclopramide was found to cause a large increase in the density of the negatively charged silanols on the silica surface. The ionization of silica was dependent on the concentration of dissolved metoclopramide at low pH but was found to be constant over a wide concentration range at pH 7.0 or higher. Adsorption studies with unionized silica indicated that specific interactions with the surface silanols occur as well as non-specific interactions driven by hydrophobic bonding with the surface siloxane groups. There was an increase in the adsorption of metoclopramide with increasing ionization of the silica surface which suggested that the negatively charged silanols constituted an additional adsorption site.
The mechanism of the interaction was elucidated by potentiometric titration with various probe compounds. The titration data with lidocaine suggested that the ionization of the surface silanols is influenced by specific interactions with the adsorbed compound rather than concentration effects. The ionized site density of silica was found to be related to the relative magnitude of the aromatic π-electron density of the adsorbed benzamides. A comparison of these titration data with that of triethylamine indicated that ionic interactions between the positively charged amine groups and the negatively charged silanols are likely to be occurring. Based on the difference in chemical structure, the titration data with dissolved ephedrine indicated that the other site of interaction is likely to be between the carbonyl oxygen of the adsorbed benzamides and the unionized silanols. The pH dependence of the ionization of silanols for both adsorption sites suggested that silanols interact simultaneously with several functional groups on a single adsorbed molecule.
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Jeder, Asma. "Matériaux carbonés par voie hydrothermale à partir de noyaux d'olive : étude du procédé, caractérisation des produits et applications." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0219/document.
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La carbonisation hydrothermale transforme les déchets municipaux (copeaux de bois, boues d'épuration, bagasse, feuilles…) en un produit solide appelé bio-charbon. Le produit hydrothermal connu sous le nom hydrochar est fréquemment utilisé comme carburant ou engrais, mais aussi il pourrait être converti en un produit à haute valeur ajoutée, à savoir le charbon actif. L‘objectif principal de cette thèse est d‘étudier la transformation de grignon d‘olive, précurseur lignocellulosique largement disponible en Tunisie et en pays méditerranéen, en hydrochar et en charbon actif. Dans cette étude, un réacteur discontinu de laboratoire a été conçu et construit. Les grignons d‘olive transformés en hydrochar ont été préparés à différentes sévérités et avec addition de sels, acide et ammoniac. Les hydrochars ont été caractérisés par plusieurs méthodes d‘analyse. L‘eau de traitement de la carbonisation hydrothermale a été analysée et les résultats montrent qu‘elle contient des composants à haute valeur ajoutée comme le furfural et le 5-HMF. Les charbons actifs ont été préparés à partir du hydrochar suivant des voies d‘activation physique (à l‘aide de l‘agent d‘activation CO2) et voies d‘activation chimique (par l‘agent d‘activation KOH). Les matériaux obtenus ont une surface spécifique élevée (1400 m2g-1) et aussi une chimie de surface riche en groupe fonctionnel. Les performances de ces charbons actifs dans l‘adsorption de molécules pharmaceutiques en phase liquide et de l‘hydrogène en phase gazeuse ont été examinées. Des capacités intéressantes ont été relevées pour les deux applicationsHydrothermal carbonization process uses green waste from municipalities (Wood chips, sewage sludge, bagasse, leaves …) to produce solid bio-coal. The solid HTC product known as hydrochar commonly used as a fuel or fertilizer but it could be converted also into high- value products like activated carbon. The principal purpose of this thesis is to study the conversion of olive stones, widely available lignocellulosic biomass in Tunisia and Mediterranean country, into hydrochar and then activated carbon. In this study, a laboratory scale batch reactor has been designed and built. The hydrothermally carbonized olive stones were prepared at different reaction severity and with addition of salts, acid or ammonia. All prepared hydrochar are characterized by different analysis methods. The HTC water was also analyzed and the results show that HTC-liquid contains high added value components such as furfural and 5-HMF. The hydrothermally carbonized olive stones were activated by both physical activation, using CO2 and chemical activation, using KOH. The materials had high surface area (as high as 1400 m2 g-1) and rich surface chemistry. The potential for pharmaceuticals (Ibuprofen and Metronidazole) and hydrogen adsorption were assessed for HTC-activated carbon and they showed good performance in both application
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Patel, Dhaval D. "KINETICS AND MECHANISMS OF CRYSTAL GROWTH INHIBITION OF INDOMETHACIN BY MODEL PRECIPITATION INHIBITORS." UKnowledge, 2015. http://uknowledge.uky.edu/pharmacy_etds/47.
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Supersaturating Drug Delivery Systems (SDDS) could enhance oral bioavailability of poorly water soluble drugs (PWSD). Precipitation inhibitors (PIs) in SDDS could maintain supersaturation by inhibiting nucleation, crystal growth, or both. The mechanisms by which these effects are realized are generally unknown. The goal of this dissertation was to explore the mechanisms underpinning the effects of model PIs including hydroxypropyl β-cyclodextrins (HP-β-CD), hydroxypropyl methylcellulose (HPMC), and polyvinylpyrrolidone (PVP) on the crystal growth of indomethacin, a model PWSD. At high degrees of supersaturation (S), the crystal growth kinetics of indomethacin was bulk diffusion-controlled, which was attributed to a high energy form deposited on the seed crystals. At lower S, indomethacin growth kinetics was surface integration-controlled. The effect of HP-β-CD at high S was successfully modeled using the reactive diffusion layer theory. The superior effects of PVP and HPMC as compared to HP-β-CD at high S were attributed to a change in the rate limiting step from bulk diffusion to surface integration largely due to prevention of the high energy form formation. The effects of PIs at low S were attributed to significant retardation of the surface integration rate, a phenomenon that may reflect the adsorption of PIs onto the growing surface. PVP was selected to further understand the relationship between adsorption and crystal growth inhibition. The Langmuir adsorption isotherm model fit the adsorption isotherms of PVP and N-vinylpyrrolidone well. The affinity and extent of adsorption of PVP were significantly higher than those of N-vinylpyrrolidone, which was attributed to cooperative interactions between PVP and indomethacin. The extent of PVP adsorption on a weight-basis was greater for higher molecular weight PVP but less on a molar-basis indicating an increased percentage of loops and tails for higher molecular weight PVPs. PVP significantly inhibited indomethacin crystal growth at high S as compared to N-vinylpyrrolidone, which was attributed to a change in the growth mechanism resulting in a change in the rate limiting step from bulk diffusion to surface integration. Higher molecular weight PVPs were better inhibitors than lower molecular weight PVPs, which was attributed to a greater crystal growth barrier provided by a thicker adsorption layer.
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Yu, Peng. "Studies of the adsorption of barbituric acid derivatives from solution by activated carbons - wet chemistry and computational chemistry." Diss., University of Iowa, 2019. https://ir.uiowa.edu/etd/6897.
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Adsorption processes are utilized in both medicine and industry. It is important to have an understanding of adsorption processes to better predict the outcomes and discern potential difficulties. The primary objective of this research is to further the understanding of the nature and extent of the adsorption process in solution, which is a function of the chemical composition of the adsorbates, adsorbents, and solvent.
This was accomplished by employing experimental studies as well as thermodynamic calculations and molecular dynamic simulations. Four activated carbons were used as the model adsorbents in this study. And, barbital, phenobarbital and primidone were used to elucidate the structural features of the adsorbates that were most responsible for the interaction with activated carbons. A Two-Mechanism Langmuir-Like Equation (TMLLE) was proposed to describe the independent presence of two adsorption mechanisms: non-site-specific adsorption and site-specific adsorption. The analyses of data generated by both previous investigators and current studies, suggest that the TMLLE allows an accurate analysis of the adsorption process. Based on the parameters in the TMLLE, the Modified Crisp Model and the van’t Hoff Model were employed to determine the Gibbs free energy changes for both site-specific adsorption and non-site-specific adsorption. Comparing the Gibbs free energy changes calculated by the Modified Crisp Model and the van’t Hoff Model (site-specific adsorption case), it is concluded that 5 water molecules are displaced by a phenobarbital molecule on the surface of activated carbons. And, for non-site-specific adsorption, it is concluded that 12 water molecules are displaced by a phenobarbital molecule on the nonpolar (hydrocarbon) part of the activated carbon surface. The adsorption of phenobarbital from solution by activated carbons has been simulated by employing Molecular Dynamic (MD) Modeling. The predicted differential Gibbs free energy values for site-specific adsorption at pH 2-9 were consistent with the thermodynamic calculations. And, the present MD simulations provide a good basis for the further understanding and quantitatively assessment of the adsorption driven by hydrophobic bonding. The conclusions reached in the current studies are expected to be applicable to a wide range of similar adsorption processes.
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Haro, Nathalia Krummenauer. "Remoção dos fármacos atenolol, paracetamol e ampicilina por adsorção em carvão ativado." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/172254.
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Os fármacos são essenciais para a preservação da saúde do homem e de animais e também na prevenção de doenças. Entretanto, seu alto consumo associado ao descarte incorreto e aos tratamentos ineficientes de águas e efluentes podem trazer grandes prejuízos ao meio ambiente como, por exemplo, a resistência bacteriana. O objetivo deste trabalho foi estudar a remoção de ampicilina (AMP), atenolol (ATN) e paracetamol (PAR), fármacos de três classes distintas, em soluções aquosas através da técnica de adsorção em carvão ativado granular (CAG). Foram realizados experimentos de adsorção em batelada avaliando o efeito dos parâmetros pH, tempo de contato e concentração de sólido adsorvente. O comportamento cinético da adsorção dos fármacos em carvão ativado granular foi avaliado por meio dos modelos de pseudo-primeira ordem, pseudosegunda ordem e difusão intrapartícula. Ainda, isotermas de equilíbrio para estes sistemas foram construídas em diferentes temperaturas (15, 25 e 35 °C) e analisadas através dos modelos de Langmuir, Freundlich e Sips. O processo de adsorção também foi avaliado através de ensaios termodinâmicos. A adsorção em coluna de leito fixo foi avaliada utilizando planejamentos experimentais para os fármacos e os efeitos da massa do leito de adsorvente (0,5 – 1,5 g) e da vazão de alimentação (10 – 15 mL min-1) foram estudados Ainda, a fim de se avaliar o comportamento dos fármacos quando em mistura, foram realizados ensaios de adsorção em batelada e em coluna de leito fixo da mistura de ampicilina e paracetamol. Os melhores resultados encontrados nos ensaios de adsorção batelada foram: pH 6 e concentração de sólido adsorvente de 10 g L-1 para os três fármacos. O tempo de adsorção mais adequado foi de 90 minutos para o ATN e 120 min para AMP e PAR. Nessas condições foi possível obter remoções de 90 %, 94 % e 96 % para a ampicilina, atenolol e paracetamol, respectivamente. O modelo cinético que melhor descreveu o processo de adsorção foi o de pseudo-primeira ordem, para os fármacos ampicilina e paracetamol, e pseudo-segunda ordem para o atenolol. As isotermas obtidas para os fármacos indicaram que o processo de adsorção é de natureza endotérmica, ou seja, a adsorção é favorecida com o aumento da temperatura. Para a AMP, o melhor ajuste das isotermas foi obtido pelo modelo de Langmuir nas temperaturas de 15 ºC e 25 ºC e pelo modelo de Sips na temperatura de 35 ºC. Para o ATN, o melhor ajuste foi obtido pelo modelo de Freundlich e, para o PAR, o modelo de Sips, nas três temperaturas estudadas. Os ensaios termodinâmicos indicaram que o processo de adsorção dos fármacos é favorável e espontâneo e comprovou a natureza endotérmica do processo Em relação aos resultados obtidos na adsorção em coluna de leito fixo foi observado que os tempos de ruptura e de saturação aumentam com o aumento da massa de sólido presente no leito e diminuem com o aumento da vazão. A massa de adsorvente apresentou efeito negativo sobre a fração de leito utilizado e foi significativa no processo de adsorção dos três fármacos. Já a vazão de alimentação só foi significativa na adsorção em leito fixo da AMP e apresentou efeito positivo na fração de leito utilizado. Os maiores volumes de efluente tratado foram obtidos com a maior massa de sólido utilizada (1,5 g) e com a menor vazão de alimentação testada (10 mL min-1). Na adsorção multicomponente em batelada, verificou-se que há concorrência entre os fármacos pelos sítios ativos do CAG disponíveis para adsorção. Os resultados obtidos nos ensaios das isotermas de adsorção mostraram que o comportamento dos fármacos em mistura é o mesmo que quando comparados individualmente. Os modelos que melhor se ajustaram aos dados experimentais foram os mesmos obtidos nos ensaios monocomponente, Langmuir para a AMP e Sips para o PAR. Da mesma forma que para os experimentos em coluna monocomponente, os ensaios multicomponentes demostraram que os tempos de ruptura e de saturação são maiores para o PAR. Entretanto, esses valores são menores do que na adsorção individual indicando que houve concorrência entre os fármacos pelos sítios do adsorvente. Os resultados encontrados indicam que a adsorção é uma alternativa viável para a remoção de fármacos, contribuindo, assim, para o avanço das pesquisas relacionadas ao tratamento de efluentes contaminados por estes poluentes.Drugs are essential for preservation of human and animal health as well as for disease prevention. However, its high consumption associated with incorrect disposal and inefficient treatment of water and effluents can cause great damage to the environment such as bacterial resistance, for example. The objective of this work was to study the removal of ampicillin (AMP), atenolol (ATN) and paracetamol (PAR), drugs of three different classes, in aqueous solutions by adsorption technique in granular activated carbon (GAC). Adsorption experiments were carried out in batch evaluating the effect of parameters pH, contact time and concentration of solid adsorbent. The kinetic behavior of the adsorption of drugs in granular activated carbon was evaluated through the pseudofirst order, pseudo-second order and intraparticle diffusion models. Furthermore, equilibrium isotherms for these systems were made at different temperatures (15, 25 and 35 ° C) and analyzed using the Langmuir, Freundlich and Sips models. The adsorption process was also evaluated through thermodynamic tests. The fixed bed column adsorption was evaluated by experimental planning for drugs and the effects of mass of the adsorbent bed (0.5 to 1.5 g) and feed rate (10 - 15 ml min-1) were studied Also, in order to evaluate the behavior of the drugs when in mixture, adsorption tests were carried out in batch and in fixed bed column for the mixture of ampicillin and paracetamol. The best results found in the batch adsorption tests were: pH 6 and concentration of adsorbent solid of 10 g L-1 for the three drugs. The most suitable adsorption time was 90 minutes for ATN and 120 min for AMP and PAR. Under these conditions it was possible to obtain removals of 90%, 94% and 96% for ampicillin, atenolol and paracetamol respectively. The kinetic model that best described the adsorption process was the pseudo-first order for the ampicillin and paracetamol drugs and pseudo-second order for atenolol. The isotherms obtained for the drugs indicated that the adsorption process is of endothermic nature, that is, the adsorption is favored with the increase in temperature. For the AMP, the best isotherm adjustment was obtained by the Langmuir model at temperatures of 15 °C and 25 °C and by the Sips model at temperature of 35 °C. For the ATN, the best fit was obtained by the Freundlich model and, for PAR, the Sips model at the three temperatures studied. The thermodynamic tests indicated that the adsorption process of the drugs was favorable and spontaneous and confirmed the endothermic nature of the process Regarding the results obtained in adsorption in fixed bed column, it was observed that rupture and saturation times increase with the increase of the mass of solid present in the bed and decrease with the increase of flow. The adsorbent mass had a negative effect on the used bed fraction and was significant in the adsorption process of the three drugs. The feed flow was only significant in the adsorption in fixed bed of the AMP and had positive effect in the used bed fraction. The highest volumes of treated effluent were obtained with the largest mass of solid used (1,5 g) and with the lowest feed rate tested (10 mL min-1). In multicomponent adsorption in batch, it was found that there is competition between the drugs by the active sites of GAC available for adsorption. The results obtained in the adsorption isotherms tests showed that the behavior of the drugs in mixture is the same as when compared individually. The models that best fit the experimental data were the same ones obtained in the monocomponent tests, Langmuir for AMP and Sips for PAR. Similarly as for the monocomponent column experiments, the multicomponent tests showed that the break and saturation times are larger for the PAR. However, these values are lower than in individual adsorption indicating that there was competition between the drugs for the sites of the adsorbent. The results indicate that adsorption is a viable alternative for the removal of drugs, thus contributing to the advancement of research related to the treatment of effluents contaminated by these pollutants.
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De, Oliveira Tiago. "Absorption de produits pharmaceutiques par les organoclays : des matériaux polyvalents pour des applications environnementales." Thesis, Orléans, 2019. http://www.theses.fr/2019ORLE3001.
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L’adsorption sur un substrat représente un moyen simple, efficace et peu couteux pour remédier aux polluants inorganiques et organiques. Les minéraux argileux ont montré par le passé des propriétés d’adsorption exceptionnelles pour de nombreux composés organiques. La modification chimique de leur surface via l’intercalation de surfactant, pour la préparation d’organoclays, permet d’améliorer leurs capacités d’adsorption, en particulier vis-à-vis des composés organiques hydrophobes tels que les produits pharmaceutiques (PPs) qui sont de plus en plus fréquemment retrouvés dans les réseaux d’eaux usées ainsi que les eaux de surface de par leurs fortes consommations et excrétions par la population associées à une inefficacité des systèmes épuratoires conventionnels pour éliminer ces composés. Dans ces travaux, l’adsorption de PPs d’actions thérapeutiques différentes et aux propriétés physico-chimiques variées sur une smectite de référence et des organoclays préparés au moyen de différents surfactants (cationiques et nonioniques) a été étudiée avec une attention particulière sur la détermination des mécanismes d’interactions entre PPs et adsorbants selon diverses conditions expérimentales afin (i) d’évaluer la stabilité des matériaux pour une application en contexte épuratoire et (ii) appréhender le rôle des phases minérales dans le devenir des micropolluants organiques dans le milieu naturel. Les données expérimentales obtenues par un jeu de techniques complémentaire révèlent que les organoclays de manière générale et plus particulièrement ceux préparés avec des surfactants nonioniques semblent être les matériaux les plus polyvalents pour l’adsorption des PPs. Les résultats soulignent également l’importance du milieu hydrophobe généré par l’intercalation de surfactants qui offrent de nouveaux sites d’interaction pour l’adsorption des PPs. Ceci permet de statuer de l’efficacité et du caractère prometteur des organoclays quant à leurs capacités de remédiation des effluents en station d’épurationAdsorption represents an easy, simple and low-cost way to remove both organic and inorganic pollutants in water. Clay minerals are well known for their outstanding adsorption properties for numerous products. The chemical modification of its surface through the intercalation of surfactants for the preparation of organoclays considerably improves the adsorption properties, in particular for hydrophobic organic compounds such as pharmaceutical products (PPs) which are more and more commonly found in sewage and surface water. In the present contribution, the adsorption PPs with different therapeutic actions and varied physicochemical properties onto clay mineral and organoclay derivatives prepared with different surfactants (cationic and nonionic) has been studied with a particular understanding of the interactional mechanisms of PP with the adsorbents in order to (i) evaluate the stability of materials for an application in purifying context and (ii) to apprehend the role of the mineral phases in the fate of organic micropollutants in the natural environment. The experimental data obtained by a set of complementary techniques reveal that organoclays prepared with nonionic surfactants show a versatility for numerous PPs while the hydrophobic environment generated by the grafting of surfactants with alkyl-chains particularly enhances the adsorption of the organic compounds. The study confirmed the efficiency and the promising remediation behavior of organoclays for wastewater treatment
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Mohabbati, Sheila. "Separation of Proteins with Capillary Electrophoresis in Coated Capillaries with and without Electroosmosis : Studies on Zone Broadening and Analytical Performances." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Universitetsbiblioteket [disributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6913.
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Guedidi, Hanen. "Préparation et modification de carbones activés pour l'adsorption de polluants organiques émergents : molécules pharmaceutiques et liquides ioniques." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAA003/document.
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Dans ce travail, nous avons modifié deux carbones activés (grain AC et tissu T0) par divers traitements chimique (H2O2, NaOCl et un traitement thermique sous azote) et par des traitements ultrasonores à 20 et 500 kHz en présence de différents solvants (eau ultrapure, peroxyde d'hydrogène et acide formique). Ces carbones (bruts et modifiés) ont été caractérisés du point de vue de leur chimie de surface et de leur texture. Nous avons étudié l'adsorption d'ibuprofène (IBP) aux différents pH et températures. Le processus d'adsorption de l'IBP sur (AC ou T0) est avéré endothermique à pH 3. L'oxydation par NaOCl crée des groupes phénoliques qui défavorisent l'adsorption d'IBP tandis que l'oxydation par H2O2 augmente la teneur en groupe carbonyles et carboxyles responsable d'une contribution à l'adsorption de l'IBP. Le traitement ultrasonore de AC a augmenté son adsorption d'IBP par rapport au charbon brut. La cinétique d'adsorption de deux liquides ioniques synthétisés (LI1 : bromure de 4-tertiobutyl-1-propylpyridinium et LI2 : bromure de 4-tertiobutyl-1(2-carboxy-ethyl)pyridinium ) sur T0 est beaucoup plus rapide que la cinétique d'adsorption de l'IBP à pH 7,5. La compétition d'adsorption sur T0 entre les trois molécules (IBP et les deux liquides ioniques) a montré que l'IBP s'adsorbe en plus grande quantité sur le T0 que le LI1 et le LI2In this work, two activated carbons (granular AC and fabric T0) were modified either by chemical treatment (H2O2, NaOCl and thermal treatment under N2) or by ultrasonic irradiation at 20 kHz or 500 kHz in different solvents (UHQ water, H2O2 and HCOOH). The raw and modified materials were characterized by different methods. We studied the ibuprofen (IBP) adsorption at different pH and temperatures. The adsorption of IBP by (AC or T0) was an endothermic process at pH 3. Oxidation with NaOCl creates phenol groups that led to a decrease of the adsorption uptake while oxidation by H2O2 increases the carbonyl group content and carboxyl that induce an increase in the adsorption of IBP. The ultrasonic treatment of AC increases the adsorption capacity of ibuprofen in comparison with the raw AC. The adsorption of the two ionic liquids (LI1 : the 4(tert-butyl)-1propylpyridinium bromide and LI2 : 4(tert-butyl)-1(2-carboxy-ethyl)pyridinium bromide ) onto T0 was found much faster than the adsorption kinetic of IBP at pH 7.5. The competitive adsorption of mixture of IBP and the two ionic liquids showed that IBP is the most adsorbed by T0
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Bednárová, Paula. "Studium mobility vybraných léčiv v přírodních systémech." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433483.
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This diploma thesis focuses on interactions of chosen pharmaceuticals with soil and study their mobility. First part is devoted to the characteristics of the most common pharmaceuticals that appear in the environment, specifically antibacterial chemoterapeutics and analgetics. Subsequently, the occurrence of the pharmaceuticals in environment, their sources and effects are described. Further, the work focuses on soil components and soil organic matter. In conclusion of the theoretical part is the description of used analytical method for processing of the results and also the current state of the problematics. In the practical part of the thesis the experiments were made and analyzed and further served for better understanding of adsorption and interactions of chosen pharmaceuticals with soil and humin acids as the main reactive part of the soil.
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Jouanny-Bouyer, Eléonore. "Stabilisation d'émulsions d'intérêt pharmaceutique par des protéines et des polysaccharides : exemples de la β-lactoglobuline, de la gomme arabique et de la gomme xanthane." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-01056468.
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L'objectif de cette étude a été de formuler et caractériser des émulsions simples huile/eau d'intérêt pharmaceutique stabilisées par de la β-lactoglobuline (β-lg), de la gomme arabique (GA), de la gomme xanthane (GX) et des mélanges β-lg:GA et β-lg:GX. Les concentrations massiques totales des dispersions de biopolymères étaient de 1 % et ont été augmentées à 2,5 % si les émulsions formulées n'étaient pas stables. Le mélange β-lg:GA a été réalisé à pH 4,2 afin de permettre la formation de complexes par interactions électrostatiques attractives entre la β-lg et la GA. Deux ratios β-lg:GA ont été étudiés : 2:1 et 1:2. Enfin, le mélange β-lg:GX a été effectué à pH 7, où les deux biopolymères étant chargés négativement ne se complexent pas et à un ratio de 1:1. Une étude de stabilité des émulsions a été menée sur 6 mois. Les stabilités obtenues ont pu être classées par ordre croissant : GA 2,5 % < β-lg:GA 2,5 % < β-lg 2,5 % < GX 1 % = β-lg:GX 1 %. Plusieurs mécanismes de stabilisation ont été mis en évidence grâce à l'étude des propriétés interfaciales des biopolymères, à l'étude des propriétés rhéologiques des émulsions et à des observations au microscope confocal à balayage laser des émulsions après marquage des biopolymères à la fluorescence. La β-lg et la GA sont toutes deux capables de s'adsorber à l'interface des globules huileux alors que la GX augmente la viscosité de la phase continue. L'association β-lg:GA conduit à la formation d'une double couche interfaciale stabilisante. Enfin, l'association β-lg:GX combine les mécanismes de stabilisation de la protéine, par adsorption interfaciale et de la gomme, par augmentation de la viscosité de la phase continue.
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Oliveira, Gonçalo Vieira Saraiva de. "Removal of pharmaceuticals from water using paper pulp-based carbon adsorbents." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22241.
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Mestrado em Biotecnologia Industrial e AmbientalThe occurrence of pharmaceuticals in the environment, mainly aquatic, is a worrying issue, with Wastewater Treatment Plants (WWTP) being the main entry route of these compounds due to their inefficient ability to remove them from contaminated water. Adsorption is a very effective method for this purpose, with activated carbons being the most commonly used adsorbents. Considering that commercial activated carbons are expensive, in part due to the price of their precursors, the production of adsorbents from alternative raw materials is an interesting solution and fits within the concept of sustainable economy. In this work, two type of pulps, bleached (BP) and raw pulp (RP), derived from the pulp and paper production process, were used as precursors for production of non-activated and activated carbons. For activated carbons, the pulps were impregnated with two chemical activating agents (K2CO3 or H3PO4), and then pyrolysed and washed with acid. After production, the materials were physically and chemically characterized. To test the performance of these carbons as adsorbents, batch adsorption tests were performed with ultra-pure water and with WWTP effluents, using two pharmaceuticals: the anti-epileptic carbamazepine (CBZ) and the antibiotic sulfamethoxazole (SMX). For the amounts of carbon tested, in ultra-pure water, the results showed no adsorption for non-activated carbons and good adsorption capacities for the activated ones. Comparing the adsorption tests in real effluents with CBZ and SMX, tests with SMX presented low adsorption capacities, probably due to the different interactions establish between the two pharmaceuticals and carbons surface, in the presence of high organic load. Tests with real effluents presented better adsorption capacities for carbons activated with H3PO4 and produced from BP: 92 ± 19 mg g-1 for CBZ and 13.0 ± 0.6 mg g-1 for SMX. These results indicate the potential of these pulps to be used as precursors for activated carbons that can be applied in wastewater treatment.
A existência de fármacos no meio ambiente, em particular ambientes aquáticos, constitui um problema preocupante, sendo as Estações de Tratamento de Águas Residuais (ETAR) a principal via de entrada destes compostos no meio, devido à sua ineficácia para os remover das águas contaminadas. A adsorção é um método bastante eficiente, sendo os carvões ativados os adsorventes mais comummente utilizados. Uma vez que os carvões ativados comerciais são caros, em parte devido ao preço dos seus precursores, a produção de adsorventes a partir de matérias-primas alternativas é uma solução interessante que se enquadra no conceito de economia sustentável. Neste trabalho foram utilizados dois tipos de pasta, branqueada (BP) e crua (RP), derivadas do processo de produção da pasta de papel, como precursores para a produção de carvões ativados e não ativados. Na ativação, as pastas foram impregnadas com dois agentes químicos ativantes (K2CO3 ou H3PO4) e posteriormente pirolisadas e lavadas com ácido. Após a produção, os materiais foram física e quimicamente caraterizados. De forma a testar o desempenho dos carvões enquanto adsorventes, foram realizados testes de adsorção em descontínuo com água ultrapura e com efluentes recolhidos em ETAR, utilizando dois fármacos: o antiepilético carbamazepina (CBZ) e o antibiótico sulfametoxazol (SMX). Para as quantidades de carvão utilizadas, os resultados em água-ultrapura mostraram adsorção nula para os carvões não ativados e boas capacidades de adsorção para os carvões ativados. Comparando os testes realizados para os efluentes reais com CBZ e SMX, os testes com SMX apresentaram baixas capacidades de adsorção, provavelmente devido às diferentes interações estabelecidas entre as superfícies do fármaco e do carvão, na presença de elevada carga orgânica. Os testes com efluentes reais apresentaram melhores capacidades de adsorção para carvões ativados com H3PO4 e produzidos a partir da BP: 92 ± 19 mg.g-1 para a CBZ e 13.0 ± 0.6 mg.g-1 para o SMX. Estes resultados refletem as potencialidades destas pastas para serem utilizadas como precursoras de carvões ativados, os quais podem ser aplicados no tratamento de águas residuais.
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Tokhadzé, Nicolas. "Etude des phénomènes de sorption entre médicaments et dispositifs médicaux de la perfusion : approche empirique et fondamentale par simulation moléculaire." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC006.
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Lors de la perfusion de médicaments via des dispositifs médicaux (DM) à base de matériaux polymères, des phénomènes de sorption peuvent entrainer une perte de principe actif (PA) et donc le risque de ne pas administrer la bonne dose au patient, induisant ainsi une diminution voire une perte de l’activité thérapeutique. Le but de ce travail était dans un premier temps d’étudier expérimentalement les interactions de trois PA (diazépam, paracétamol et insuline) avec des DM isolés et avec des DM au sein d’un montage complet de perfusion composé d’une seringue, d’un prolongateur et d’un cathéter. Le suivi de la concentration en PA dans la solution a été réalisé par chromatographie liquide et les matériaux ont été analysés par spectroscopie infrarouge et mesure du potentiel zêta de surface. Dans un second temps, les interactions entre deux matériaux (Polychlorure de vinyle et Polyéthylène) et deux PA (paracétamol et diazépam) ont été simulées par des méthodes de dynamique moléculaire. Ce travail a permis de mettre en évidence des pertes de PA par sorption au contact de chacun des DM. Certains matériaux sont apparus comme étant plus à risque de sorption (Polychlorure de vinyle, Polyuréthane, Silicone) que d’autres (Polyéthylène, Styrène-Ethylènebutadiène-Styrène). Pour le montage complet, si des possibilités d'amélioration existent avec les prolongateurs commerciaux, il n'en va pas de même avec les cathéters, le choix des matériaux disponibles sur le marché étant limité. Les méthodes d’analyse de surface des matériaux ont permis d’apporter de nouveaux éléments permettant une meilleure compréhension des phénomènes à l’interface matériau/médicament. Enfin, l’utilisation des méthodes de simulation numérique des interactions par dynamique moléculaire dans l’étude des phénomènes de sorption constituait une approche inédite et a permis d’objectiver certains phénomènes difficilement accessibles par l’expérience. Cette technique a notamment permis de mettre en évidence le positionnement du principe actif vis-à-vis de la surface du matériau, et le calcul des PMF de différencier les phénomènes d’absorption et d’adsorptionWhen infusing drugs via polymer based medical devices (MD), sorption phenomena can induce a loss of active pharmaceutical ingredient (API) and thus the risk of not administering the right dose to the patient, inducing then a decrease or even loss of therapeutic activity. The aim of this work was first to experimentally study the interactions of three API (diazepam, paracetamol and insulin) with MD alone and with MD within a complete infusion setup composed of a syringe, an extension and a catheter. API concentration was assessed by liquid chromatography and materials were characterized by infrared spectroscopy and surface zeta potential measurements. In a second time, the interactions between two materials (Polyvinyl chloride and Polyethylene) and two API (paracetamol and diazepam) were simulated by molecular dynamics methods. This work allowed highlighting losses of API by sorption in contact with each of the MD. Some materials appeared to be more at risk of sorption (Polyvinyl chloride, Polyurethane, Silicone) than others (Polyethylene, Styrene-Ethylene-Butadiene-Styrene). For the complete setup, even if some improvements are possible with commercially available extension sets, the situation is more difficult in the case of catheters since the choice of existing materials is limited. Material surface analysis methods have provided new elements for a better understanding of the phenomena at the material/drug interface. Then, the use of simulation of interactions by molecular dynamics in the study of sorption phenomena was a novel approach and abled to highlight phenomena that were difficult to obtain experimentally. Particularly, this technique allowed to follow the position of the API with respect to the surface of the material, and the calculation of PMF to differentiate absorption and adsorption phenomena
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Shubietah, Raqi Moh'd Hasan. "Adsorptive stripping voltammetry as a method of analysis of some pharmaceutical and other purine derivatives." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/11215.
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Adsorptive stripping voltammetry (AdSV) is a recent technique (initially named by Lam, Kalvoda and Kopanica in 1983) in which there is generally a nonelectrolytic accumulation (adsorption) of the determinand followed by a cathodic reductive or anodic oxidative scan. In this work, a hanging mercury drop electrode (HMDE) was used to accumulate several purine derivatives with and without the addition of Cu(lI) in a suitable buffer (usually Britton-Robinson, pH 7.5). In the presence of copper(lI) the copper(l) purine complex was usually accumulated at about -0.1 V. Some of the compounds studied (i.e dimenhydrinate, theophylline, guanine and azathioprine) can be determined as free compounds (i.e with no Cu(lI) added) after accumulation at potentials ranging from 0 to -0.2 V versus Ag/AgCI reference electrode. The determination of these compounds was made after optimising pH, buffer constituents, accumulation potential and accumulation time. The addition of Cu(lI) to these purines makes possible accumulation at shorter accumulation times , and improves the detection limits. For example, the detection limit of azathioprine in the presence of Cu(lI) is as low as 2x10-10 M. Both differential-pulse polarography (DPP) and DP-AdCSV (differential pulse adsorptive cathodic stripping voltammetry) were used in the determination of theophylline and azathioprine in their dosage forms (tablets). The relative standard deviations for the determination of the pharmaceutical purines in their tablets were 3.0%. 4.2% and 1.3% for the measured concentrations of dimenhydrinate(1.5x10-7 M) , theophylline(2x10-7 M) by AdSV ; and azathioprine(2x10-6 M) by DPP, respectively . Other purines (eg xanthine,1,3-dimethyluric acid and some methylguanines) did not give peak currents useful for their determination. The addition of Cu(lI) was necessary to obtain satisfactory peak currents for these purines. At low copper(lI) concentrations (Le.< 10-6 M), it is suggested that the purines form Cu(l) complexes which are adsorbed at the HMDE surface: Cu(lI) + Cu(O) + 2 L ~ 2 Cu(I)-L adsorbed.
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Jaria, Guilaine Marques. "Adsorption of fluoxetine onto waste-based activated carbon." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13664.
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Mestrado em Química - Química Analítica e QualidadeActivated carbons are one of the most promising techniques for the removal of organic and inorganic compounds from waters. In this work three activated carbons were produced using as precursor primary paper mill sludge. Chemical activation was performed using three different activation agents, KOH, NaOH and ZnCl2, and the same pyrolysis conditions were applied. The characterization of the obtained materials was made by means of total organic carbon analysis (TOC), Fourier infrared spectroscopy with attenuated total reflectance (FTIR-ATR), proximate and ultimate analysis, scanning electron microscopy (SEM), Hg porosimetry, BET isotherms and point of zero charge (PZC) determination. Adsorption studies were made, beginning with adsorption kinetic and then adsorption equilibrium (isotherms of adsorption), all performed in batch experiments. Generally, the carbons presented an equilibrium time of around six hours. Equilibrium studies allowed test the adsorption capacity of the produced carbons for fluoxetine-HCl. These two studies were also performed to the primary sludge pyrolysed under the same conditions without activation and also to a commercial activated carbon as reference. Among the produced materials, the carbon activated with ZnCl2 has the higher BET surface area and percentage of carbon. The maximum adsorption capacity (mg g-1) was of 96.2 ± 1.0 for PBFG4; 120.4 ± 2.5 for PS800-10; 191.6 ± 4.8 for PS800-10KOH; 136.6 ± 9.6 for PS800-10NaOH; and 28.4 ± 0.3 for PS800-10ZnCl2. The isotherms obtained point for different mechanism of adsorption between the carbons, probably due to their distinct PZC.
Os carvões ativados são uma das técnicas mais promissoras para a remoção de compostos orgânicos e inorgânicos presentes nas águas. Neste trabalho, foram produzidos três carvões ativados utilizando como precursor lamas primárias residuais provenientes da produção de papel. Foi utilizada a ativação química com KOH, NaOH e ZnCl2, aplicando as mesmas condições de pirólise aos três carvões. A caracterização dos materiais obtidos foi feita por meio de análise de carbono orgânico total (TOC), espectroscopia de infravermelho com transformada de Fourier usando a técnica reflexão total atenuada (FTIR-ATR), Proximate and ultimate analysis, microscopia eletrónica de varrimento (SEM), porosimetria de mercúrio, isotérmicas BET e determinação do ponto de carga zero (PZC). Foram realizados estudos de adsorção iniciados pela cinética de adsorção e seguidos das isotérmicas, usando experiências em vaso fechado. Os estudos de cinética de adsorção mostraram que, na generalidade, todos os carvões produzidos apresentaram um tempo de equilíbrio semelhante, cerca de seis horas. As isotérmicas permitiram testar a capacidade de adsorção dos carvões produzidos para o composto fluoxetina-HCl. Estes dois estudos foram também aplicados à lama primária pirolisada sob as mesmas condições mas sem ativação e também a um carvão ativado comercial, usado como referência. Entre os materiais produzidos, o carvão ativado com ZnCl2 é o que apresenta uma área superficial específica (SBET) superior e maior percentagem de carbono. A capacidade máxima de adsorção (mg g-1) foi de 96.2 ± 1.0 para o PBFG4; 120.4 ± 2.5 para PS800-10; 191.6 ± 4.8 para PS800-10KOH; 136.6 ± 9.6 para PS800-10NaOH; e 28.4 ± 0.3 para PS800-10ZnCl2. As isotérmicas obtidas apontam para a existência de diferentes mecanismos de adsorção entre os carvões, provavelmente devido aos seus valores de PZC.
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Thiebault, Thomas. "L’adsorption des produits pharmaceutiques par interactions organo-minérales : processus et applications environnementales." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2057/document.
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Les compartiments aquatiques sont pollués par des micropolluants d’origine anthropique, tels les produits pharmaceutiques. Ces pollutions sont principalement engendrées par le rejet continu des effluents des stations d’épuration les eaux naturelles. C’est pourquoi le premier objectif de ce travail fut de caractériser les capacités épuratoires des trois types de station d’épuration actuellement utilisées, les boues activées, les lagunages naturels et les filtres plantés. Les analyses des effluents ont démontré que l’épuration des produits pharmaceutiques dans ces stations est insuffisante. Il est donc nécessaire, notamment dans le cadre de le directive cadre sur l’eau, de penser à des traitements innovants et à bas coût. De part des propriétés d’adsorption significatives, les argiles naturelles comme les smectites sont des matériaux qui ont un potentiel en ce sens. Le second objectif de ce travail a donc été de mettre en interaction la smectite naturelle avec les produits pharmaceutiques dans différentes conditions expérimentales. En débutant par des conditions standards à concentrations dopées pour aboutir à des solutions naturelles. Les expérimentations ont également été menées sous différentes dynamiques pour vérifier l’adéquation du matériau choisi avec un usage en conditions industrielles. Les résultats démontrent que la smectite a une capacité d’adsorption significative sur une grande variété de produits pharmaceutiques et que cette capacité est meilleure dans des solutions complexes. Ceci permet de postuler que le matériau choisi peut représenter une solution à bas coût et efficace pour l’épuration des effluents des stations d’épurationThe water compartments are contaminated by anthropic micropollutants, as pharmaceuticals. These pollutions are mainly due to the constant spillage of effluents in natural waters. That’s why the first objective of this study was to evaluate the removal capacity of three treatment chains, activated sludge, lagoon-based system and planted filter. The effluent analyses exhibited that the removal of pharmaceuticals in these sewage plants is insufficient. It is thus necessary to think about low cost and innovative purification solution especially framed by the water framework directive. Due to significant adsorptions properties, natural clay minerals as smectites have a potential in that way. The second objective of this work was thus to realize organo-mineral interactions between the smectite and pharmaceuticals in different experimental conditions. Beginning with standard conditions and boosted concentrations to finish with natural solutions. To verify the field use of the chosen material, differents dynamics were tested. Results demonstrated that the smectite has a significant sorption capacity on a wide variety of pharmaceuticals and that this capacity is enhanced in complex solutions. This permit to postulate, that the chosen material can represent an efficient low-cost solution for the purification of the effluents of sewage treatment plants
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Pereira, José Manuel Santos. "Computational optimization of bioadsorbents for the removal of pharmaceuticals from water." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22232.
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Mestrado em Biotecnologia Industrial e AmbientalOs fármacos estão entre os contaminantes aquáticos mais persistentes, resistindo aos processos convencionais aplicados nas estações de tratamento de águas residuais (ETAR) e, muitos deles, representam uma ameaça séria para organismos não-alvo e para o meio ambiente. Neste contexto, a adsorção a carvões ativados (CA) é uma das mais promissoras metodologias para a remoção de fármacos da água dada a sua versatilidade e alta eficiência de remoção. Contudo, os CAs implicam custos elevados. A lama primária da resultante do tratamento de efluentes da indústria papeleira foi anteriormente apresentada como uma potencial fonte de carbono alternativa e barata para a produção de CA por pirólise. A química computacional pode ser uma ferramenta valiosa na elucidação de alguns aspetos do mecanismo molecular de adsorção de poluentes orgânicos a CAs. No presente trabalho , é proposta a utilização de lama primária da indústria papeleira para a produção carvões (não)ativados. Os diferentes materiais foram caracterizados por um conjunto de técnicas experimentais, e os dados adquiridos usados na formulação de um modelo computacional válido, na tentativa de reproduzir a variabilidade do CA em termos de composição elementar, grupos funcionais e porosidade. O modelo desenvolvido foi usado na obtenção de informação pertinente através de técnicas de denâmica molecular/Monte Carlo que possibilite o melhoramento do CA inicial. Os resultados adquiridos em simulaçõesMonte Carlo sugerem que CAs com teores de oxigénio superiores apresentam valores de área superficial mais elevados, e, consequentemente, capacidades máximas de adsorção superiores. A presença de iões positivos no meio de adsorção apresenta-se como um fator cooperativo para a adsorção de SMX, dada a formação de complexos CA-Na+-SMX em dupla camada e estabilização de conformações abertas, tal como demonstrado através de simulações de dinâmica molecular.
Pharmaceutically active ingredients are amongst the most persistent wastewater contaminants, resisting to wastewater treatment plants (WWTP) conventional processes, and some of them are proved to pose serious threats to organisms and the environment. In this contect, adsorption by activated carbons (AC)is one of the most promising methodologies for the removal of pharmaceuticals from water due to its versatility and high removal efficiency. However, ACs are expensive and therefore now widely applied. Primary sludge from paper mills has been previously appointed as a potential cheap and renewable source of carbon for activated carbon production by pyrolysis. Computational chemistry may help shed some light unto the molecular mechanisms underlying the adsorption of organic pollutants in ACs. In this work, it is proposed the usage of primary paper mill sludge in the production of (non)activated carbons. The different materials were characterized by a set of techniques and the gathered data was used in the formulation of a validated model in an attempt to reproduce the elemental composition, functional group variability and porosity. The developed model was used in order to collect relevant information through molecular dynamics/Monte Carlo techniques, enabling the improvement of the initial AC material. The obtained data in Monte Carlo simulations suggest that AC with higher oxygen levels present greater values of surface are, and consequently superior maximum capacity values. The presence of positive ions in the adsorption medium presents itself as a cooperative factor for SMX adsorption, guven the formation of CA-Na+-SMX complexes and the estabilization of open configurations, such as demonstrated in molecular dynamics simulations.
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Tetteh, Emmanuel. "Adsorption of Pharmaceuticals and Endocrine Disrupting Compounds using Unmodified and Surfactant Modified Palygorskite-Montmorillonite Clay Particles in Batch and Fixed Bed Column Modes." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1543583842195458.
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Kabelíková, Eva. "Sledování účinnosti vybraných adsorbentů na odstraňování mikropolutantů z pitné vody." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391898.
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This diploma thesis deals with the effectiveness of selected adsorbents for the removal of micropollutants from drinking water. In the first part there are described individual types of micropollutants and their occurrence in water. Further, there are described pharmaceuticals and their consumption in the world. At the end of the first part, the possibilities of removing micropollutants in drinking water treatment are approached and two water treatment plants in the Czech Republic have been selected, which already use the technology of the removal of some micropollutants. In the practical part of this diploma thesis is performed an experiment of removal of Ibuprofen from model water by adsorption on selected materials, which are Filtrasorb F100, Bayoxide E33 and GEH.
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Riegger, Benjamin R. [Verfasser], and Günter E. M. [Akademischer Betreuer] Tovar. "Synthesis of bio- and synthetic-based functional nanoparticles via inverse miniemulsion for the adsorption and detection of pharmaceuticals in aqueous media / Benjamin R. Riegger ; Betreuer: Günter E. M. Tovar." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2021. http://d-nb.info/1239116039/34.
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Elversson, Jessica. "Spray-Dried Powders for Inhalation : Particle Formation and Formulation Concepts." Doctoral thesis, Uppsala University, Department of Pharmaceutical Chemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5904.
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Spray drying is a method with a high potential in the preparation of protein particles suitable for pulmonary delivery. However, surface induced denaturation of bio-molecules during atomization and subsequent drying can be substantial and it is therefore important to develop new formulation concept for concurrent encapsulation and stabilization of proteins during spray drying. Hence, with an overall objective to increase the knowledge of the formation of particulate systems for systemic administration of proteins by spray drying, the first part of this thesis, systematically investigated the particle formation by droplet size and particle size measurements. It was described how specific properties, such as the solubility and the crystallization propensity of the solute, can affect the product, e.g. the particle size, internal structures, and possibly particle density. A new method using atomic force microscopy (AFM) for the assessment of the effective particle density of individual spray-dried particles was demonstrated. In the second part, two different formulation concepts for encapsulation of protein during spray drying were developed. Both systems used non-ionic polymers for competitive adsorption and displacement of protein from the air/water interface during spray drying. The aqueous two-phase system (ATPS) of polyvinyl alcohol (PVA) and dextran, and the surface-active polymers, hydroxypropyl methylcellulose (HPMC) and triblock co-polymer (poloxamer 188) used for in situ coating, proved efficient in encapsulation of a model protein, bovine serum albumin (BSA). Inclusion of polymeric materials in a carbohydrate matrix also influenced several particle properties, such as the particle shape and the surface morphology, and was caused by changes in the chemical composition of the particle surface and possibly the surface rheology. In addition, powder performance of pharmaceutical relevance, such as dissolution and flowability, were affected.
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Quesada, Penate Isariebel. "Metodos no convencionales para el tratamiento de aguas contaminadas con productos farmaceuticos." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT013G/document.
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Des solutions modèles de lévodopa et de paracétamol, représentatives d'effluents pharmaceutiques, ont été traitées par adsorption et par des techniques non conventionnelles comme les ultrasons, l'oxydation en voie humide catalytique et le procédé séquentiel adsorption-oxydation ADOX, en utilisant des charbons actifs comme adsorbants et/ou catalyseurs. Les isothermes d'adsorption des deux composés sur trois charbons actifs ont été caractérisées, puis en oxydation, la puissance et la fréquence optimales des ultrasons ont été déterminées. Enfin, les études de cinétique d'oxydation catalytique en réacteur discontinu et du procédé séquentiel adsorption-oxydation en lit fixe ont montré que les propriétés morphologiques et les groupes superficiels présents sur le charbon actif jouent un rôle fondamental quand ce dernier est réutilisé pour plusieurs cycles d'oxydationThe treatment of model aqueous solutions of paracetamol and levodopa, similar to those of pharmaceutical effluents, was studied. Adsorption and non conventional techniques, such as ultrasound, catalytic wet air oxidation and the sequential adsorption-oxidation AD-OX process, were evaluated. The activated carbons were used as adsorbents and catalysts. The adsorption isotherms of both products were experimentally determined on three activated carbons and then, the corresponding mathematical models were fitted. For oxidation under US, the optimal values of the ultrasonic power and frequency were determined. Finally, the kinetic study of CWAO of paracetamol and levodopa in a batch reactor and the sequential adsorption-oxidation of paracetamol in a fixed bed column showed that the morphological properties and the surface groups of activated carbons play an important role for the recycling of the carbons as catalysts
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Moravčíková, Světlana. "Sledování účinnosti odstraňování léčiva z vody vybranými adsorbenty." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409703.
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This diploma thesis deals with the efficiency of removal of pharmaceuticals from drinking water by selected adsorption materials. The first part describes sources of pharmaceuticals in drinking water and possible ways of contaminating water by pharmaceuticals. Subsequently, the pharmaceuticals most commonly found in the environment - nonsteroidal anti-inflammatory drugs, antibiotics, psychiatric drugs and sex hormones - are described in more detail. Next, the thesis describes the processes used for removal of pharmaceuticals. These are activated carbon adsorption, membrane processes and advanced oxidation processes. The last chapter of the theoretical part of the thesis deals with water treatment plants, where the technologies for removing drugs are already in operation. In the practical part of this thesis an experiment was performed and evaluated, for a purpose of comparing the efficiency of selected sorption materials in the removal of diclofenac from water. Filtrasorb F100, Bayoxide E33 and GEH were used.
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Mallek, Maryam. "Analytical methodology based on a silicone rod (SR) micro extraction combined with HPLC-DAD method for the determination of pharmaceuticals and antibacterial products in effluent wastewaters: characterization of the sorption removal processes by cork." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/669295.
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Solid-phase microextraction (SPME) allow the achievement of high enrichment levels by using small volumes of solvents, enabling the low detection limits required for the determination of ketoprofen, naproxen, carbamazepine, diclofenac, and triclosan in matrices of environmental interest to be obtained using HPCL-DAD. The state of art of the different SPME techniques and their latest innovations has been reviewed. An analytical method based on microextraction with polymethylsiloxane rods (PDMS) and studying the different parameters and conditions that affect the extraction stages (pH, organic modifier, ionic strength, kinetics and sample volume) and desorption (solvent, solvent volume, desorption time and sonication application). It has been shown that granulated cork can be a low-cost alternative for the elimination of PPCPs and phenolic compounds from water given that it has a high adsorption capacity towards these pollutantsLes tècniques de microextracció en fase sòlida (SPME) permeten obtentir alts factors d'enriquiment emprant petits volums de solvents fent possible que s'assoleixin els baixos límits de detecció requerits per la determinació de ketoprofen, naproxen, carbamazepina, diclofenac i triclosan en matrius d'interès ambiental emprant HPLC-DAD. S'ha revisat l'estat de l'art de les diferents tècniques de SPME i les seves darreres innovacions. S'ha desenvolupat i validat un mètode analític basat en la microextracció amb vareta polidimetilsiloxà (PDMS) i HPLC-DAD per la determinació de PPCPs, estudiant-ne els diferents paràmetres i condicions que afecten a les etapes d'extracció (pH, modificador orgànic, força iònica, cinètica i volum de mostra) i de desorció (dissolvent, volum, temps de desorció i aplicació de sonicació). S'ha demostrat que el suro granulat pot ser una alternativa de baix cost per l'eliminació de PPCPs i compostos fenòlics de les aigües atès que la seva capacitat per adsorbir aquests contaminants és alta
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Kapsabelis, Susan. "Polymer-particle interactions : adsorption of ethyl(hydroxyethyl)cellulose (EHEC) onto modified silica and pharmaceutical particle surfaces." 2001. http://arrow.unisa.edu.au:8081/1959.8/50784.
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Olivera, Agustina Raquel de. "Biosorption of pharmaceuticals from wastewater using Moringa oleífera as biosorbent." Master's thesis, 2018. http://hdl.handle.net/10198/22123.
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Mestrado de dupla diplomação com a Universidad Nacional de MissionesPharmaceuticals as emerging contaminants have become one of the most controversial environmental issues at global scale. Over the years, there has increased the presence of antibiotics and anti-inflammatory drugs inside rivers, lakes, oceans and even inside drinking water streams. The waste-water treatment plants (WWTPs) lack the necessary technology to remove a concentration between the range ng/l-mg/l and therefore, the need to develop new methods able to remove contaminants in an effective, low cost and environmental friendly way arises. The term “Biosorption” appears as a possible solution. It is a separation process inside the area of Chemical Engineering that follows the same fundaments of adsorption with the only difference that uses biodegradable materials as adsorbent (biosorbent). The present work focuses on studying the potential adsorption capacity of Moringa oleífera (MO) to remove Diclofenac (DCF) and Oxytetracycline (OTC) from waste-water. After different experiments, it was found that in both cases (DCF and OTC) the adsorption processes present high pH dependence, the first one governed by the mechanism of chemisorption while the second one could be controlled by diffusion of the particles between both surfaces. Equilibrium isotherms were determined by Langmuir, Freundlich, and Sips models. In both cases, the adsorption process was best described by the Freundlich model (R2>0.97). Kinetics essays were described by pseudo-first-order, pseudo-second-order, and Intraparticle diffusion models. The experimental data of OTC and DCF removal were best fitted by Intraparticle Diffusion (R2>0.95) and pseudo-second-order (R2>0.93) model respectively. It was possible to obtain a removal percentage of 88% for DCF at a pH of 2 and 50% for OTC at a pH of 10, indicating that MO represents a viable option for the removal of drugs present in contaminated water.
Los fármacos en su papel de contaminantes emergentes, se han convertido en uno de los problemas ambientales más preocupantes a escala global. Con el pasar de los años, la presencia de antibióticos y antiinflamatorios dentro de ríos, lagos, océanos e inclusive en corrientes de agua potable, ha ido aumentado. Las plantas de tratamiento de aguas residuales (ETARs) aún no cuentan con los métodos adecuados para remover concentraciones dentro del rango de ng/l-mg/l y por ello, surge la necesidad de desarrollar nuevas tecnologías que sean efectivas, de bajo costo y amigables con el medio ambiente. Como posible solución nace el término de “biosorción”. La biosorción es un proceso de separación dentro del área de Ingeniería Química que sigue los mismos fundamentos de la técnica de adsorción, con la única diferencia que utiliza materiales biodegradables como adsorbentes, conocidos como “biosorbentes”. Es de gran interés en el presente trabajo, estudiar las características, principales propiedades y capacidad de adsorción que posee las cáscaras de la planta Moringa oleífera (MO) para la remoción de Oxitetraciclina (OTC) y Diclofenac (DCF) presentes en aguas residuales. MO es reconocida mundialmente debido a sus propiedades anti-microbiales, nutricionales y coagulantes, mientras que DCF y OTC son considerados dos de los fármacos con mayor contribución a la contaminación del medioambiente. A través de diferentes ensayos, se encontró que en ambos casos (DCF y OTC) se trata de procesos altamente dependientes de pH con la diferencia que el primero es gobernado por el mecanismo de quimisorción mientras que el segundo es controlado bajo la difusión de partículas entre ambas superficies.El modelo de Freundlich (R2>0.98) ha logrado, en ambos casos, el mejor ajuste de los datos empíricos. Mientras que, en modelos de cinética de adsorción, el modelo de Difusión Intraparticular presentó el mejor ajuste para el proceso de remoción de OTC (R2>0.95) y el modelo Pseudo-Segundo-orden, para la adsorción de DCF (R2>0.93). Se ha logrado remover hasta un 88% de DCF a un pH de 2 y hasta 50% de OTC a un pH de 10, indicando que MO representa una opción viable para la remoción de fármacos presentes en aguas contaminadas.
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Lin, You-Li, and 林宥里. "Adsorption behavior of Pharmaceuticals and Personal care products on Activated Carbon." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/jpjp53.
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碩士東海大學
環境科學與工程學系
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Pharmaceuticals and personal care products are widely used in an excessive amount and improper usage, which can significantly affect the aquatic ecosystem. This study investigated the application of the commercial granular activated carbon F-400 as adsorbent on the removal of emerging contaminants of five pharmaceuticals, such as caffeine, sulfamerazine, sulfathiazole, naproxen and ibuprofen, from aquatic solution. The physicochemical properties of the adsorbent and adsorbates, and adsorption behavior of single component and mixtures were examined to understand the mass transfer mechanism. The Freundlich and Langmuir isotherms were used to predict the adsorption equilibrium for single component. The multi-component adsorption was estimated by ideal adsorbed solution theory (IAST) combined with Freundlich isotherm. The traditional dynamic models were used to predict the internal and external mass transfer coefficients from CSTR data. Finally, the rapid small scale column test (RSSCT) was used to simulate the large-scale column, of which the obtained data was compared with those of Linear driving force (LDF) model combined with Freundlich isotherm. The whole obtained data were used to evaluate the applicability of activated carbon on adsorption removal of pharmaceuticals and personal care products investigated in this study. The results of adsorption equilibrium for the sigle component indicated that both isotherms were able to well describe the adsorption equilibrium and naproxen had the highest adsorption capacity. All the values of heterogeneity factor (nF) were greater than 1, indicating the favorable adsorption of five components on F-400. The IAST combined with Freundlich isotherm mostly well predicted the competitive adsorption of five components and it was found that Kow significantly affected the predictive values in the mixture so as to diverge from the predict values. The internal mass transport were well predicted by pore diffusion and surface diffusion models, and both film diffusion and surface diffusion are important in the adsorption kinetics. The kinetic parameters obtained from surface diffusion model combined with the LDF model were used to predict the adsorption breakthrough of the mixture in the adsorption column, indicating the effective prediction of some components. Comparison of adsorption capacity with pure water system and river system as background solution, the adsorption amount was reduced due to the competition with organics in the river. Combined with parameters calculated from the data of adsorption isotherms and kinetics, the adsorption system was able to be planned and designed for the adsorption removal of PPCPs investigated in this study.
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Krona, Johanna. "Evaluation of a bark adsobent for removal of pharmaceuticals from wastewater." Thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-315260.
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During and after medical treatment, pharmaceutical compounds as well as their metabolites and conjugates are excreted from the users through urine and feces. The pharmaceuticals end up in wastewater treatment plants, which are not designed to deal with this kind of organic micro-pollutant. Eventually the pharmaceuticals end up in the environment where they can have adverse physiological and behavioral effects on aquatic life and could contribute to the spread of antibiotic resistance among microorganisms. Adsorption to activated carbon is an established method for removal of pharmaceuticals from wastewater. It is however quite expensive and it is of interest to identify cost-effective alternatives. One possible alternative is bark, which is a common by-product from forest industry and has a complex microstructure and high porosity compared to many other naturally occurring materials. In order to investigate the potential of using bark to remove pharmaceuticals from municipal wastewater four column filters were built, two with activated carbon and two with bark. They were used in an experiment conducted at Kungsängsverket, the largest wastewater treatment plant in Uppsala municipality. The objectives were to assess pharmaceutical concentrations in treated wastewater at Kungsängsverket and to compare the performance of bark and activated carbon filters under different loading rates. During this time the filters were run at different loading rates and two different types of bark was used. 24 common pharmaceuticals from different therapeutic groups were targeted. The pharmaceutical concentrations measured at Kungsängsverket were generally low, but mean concentrations of five pharmaceuticals (atenolol, metoprolol, furosemide, hydrochlorothizide and diclofenac) exceeded 250 ng/l. Out of these, four have been shown to have adverse effects on aquatic life and it would be preferable if they were not released into the recipient. Bark was not as good at removing pharmaceuticals from wastewater as activated carbon was, but decent removal rates were achieved for several compounds. The removal rates of either filter type did not seem to be significantly impacted by variations in loading rate or bark size. The concentrations of a few compounds increased after treatment with the bark filters and the reason for this is not clear. One possibility is interference from other organic substances in the wastewater or the bark, but determining the reason for this increase should be a priority for any further research on the subject. Another problem encountered during the project that is likely to pose a problem for future implementation is that the bark filters were very sensitive to clogging. Running the filters at full scale would require frequent back-washing which would be a disadvantage from both economical and practical reasons.
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Jaria, Guilaine Marques. "Production of waste-based adsorbents for the removal of pharmaceuticals from water: chemical activation and modification." Doctoral thesis, 2020. http://hdl.handle.net/10773/30466.
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The sustainable development of society implies the adoption of strategies
related to waste management and valorization (in a circular economy
perspective) and to effluent treatment (namely for the removal of
pharmaceuticals from water). Being adsorption by activated carbon (AC) a
well-established method for water treatment, this work focuses on the
production of AC using residues, namely sludge from pulp and paper industry,
for the removal of pharmaceuticals from water. This approach aims to foster an
integrated solution for the two environmental issues involved in this work.
Primary pulp and paper mill sludge (PS) showed a great potential to produce
carbon-based adsorbents, relatively to biological sludge (BS). Through the use
of PS and a production process involving chemical activation and pyrolysis, it
was possible to produce AC in both powdered and granular (using a binder
agent) forms, with high surface areas (SBET) (similar to those of commercial AC
with the same granulometry). The produced powdered AC presented, in batch
adsorption systems, adsorption capacities for the pharmaceuticals
carbamazepine (CBZ), sulfamethoxazole (SMX) and paroxetine (PAR), in the
same magnitude of commercial AC. However, when applied in wastewater
matrix, variations in the adsorption capacity of the produced AC for the studied
pharmaceutical was observed, namely in the case of SMX, which decreased,
and PAR, that increased.
The produced granular AC showed, in batch adsorption systems, lower
adsorption capacity for the three pharmaceuticals CBZ, SMX, and PAR, than
the commercial granular AC used as reference. Also, in this case, a reduction
in the adsorption capacity for CBZ and SMX was observed for wastewater
matrices. In fixed-bed column studies (continuous mode) the produced
granular AC presented a higher breakthrough volume and adsorption capacity
for CBZ for the lower flow-rate. Also, it was observed a reduction of the
adsorption capacity with the increase of the complexity of the aqueous matrix
(distilled water > wastewater > multicomponente solutions – with the three
pharmaceuticals – in wastewater).
The application of different functionalization methods to the powdered AC
surface showed to be an interesting approach, evidencing an increase in the
selectivity of some functionalized AC for some of the pharmaceuticals under
study, despite the general reduction in their SBET.
Concluding, this work demonstrates the potential of PS from pulp and paper
mill industry to produce alternative AC, particularly in the powdered form, to be
applied in the removal of pharmaceuticals from water.O desenvolvimento sustentável da sociedade implica a adoção de estratégias ligadas à gestão dos resíduos e sua valorização (numa perspetiva de economia circular) e ao tratamento de efluentes (nomeadamente, para a remoção de fármacos da água). Sendo o processo de adsorção por carvão ativado (CA) um método bem estabelecido para o tratamento de águas, este trabalho incide sobre a produção de CA a partir de resíduos, nomeadamente lamas da indústria da pasta e do papel, para a remoção de fármacos da água. Esta abordagem pretende proporcionar uma solução integrada nos dois desafios ambientais anteriormente referidos. Comparativamente com as lamas biológicas (LB), as lamas primárias (LP) da indústria da pasta e do papel, mostraram ter um grande potencial para a produção de adsorventes à base de carvão. A partir de LP, e usando um processo de ativação química e pirólise, foi possível produzir CA, quer na forma de pó, quer na forma granular (usando um agente aglomerante) com elevadas áreas superficiais (SBET) (comparáveis às de CA comerciais da mesma granulometria). Os CA produzidos em pó apresentaram, em sistemas descontínuos de adsorção, capacidades de adsorção para os fármacos carbamazepina (CBZ), sulfametoxazol (SMX) e paroxetina (PAR), da mesma ordem de grandeza que os CA comerciais. Contudo, quando aplicados em matrizes de efluente real, observam-se variações na capacidade de adsorção dos CA produzidos para os fármacos em estudo, principalmente no caso do SMX, que diminuiu, e da PAR, que aumentou. O CA granular produzido apresentou, em sistemas descontínuos de adsorção, menor capacidade de adsorção para os três fármacos CBZ, SMX e PAR, do que o CA granular comercial de referência. Também neste caso, se verificou uma redução da capacidade de adsorção da CBZ e do SMX em matrizes de efluente real. Estudos realizados em colunas de leito-fixo (modo contínuo) mostraram que o CA granular produzido apresentou maior volume de rutura e maior capacidade de adsorção da CBZ para o menor fluxo. Verificou-se, ainda, a redução da capacidade de adsorção com o aumento da complexidade da matriz aquosa (água destilada > efluente real > soluções multicomponente - com os três fármacos - em efluente). A aplicação de diferentes metodologias de modificação ou funcionalização da superfície dos CA em pó mostrou ser uma abordagem interessante, observando-se um aumento de seletividade de alguns CA funcionalizados para alguns dos fármacos em estudo, apesar da redução geral da SBET destes. Em suma, este trabalho demonstra o potencial das LP da indústria papeleira para a produção de CA alternativos aos CA comerciais, em particular para a formulação em pó, e para a sua aplicação na remoção de fármacos das águas.
Programa Doutoral em Química
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Yu, Zirui. "Analysis of Selected Pharmaceuticals and Endocrine Disrupting Compounds and their Removal by Granular Activated Carbon in Drinking Water Treatment." Thesis, 2007. http://hdl.handle.net/10012/3309.
Full textAbstract:
Over the last decade, endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhACs) have been detected in drinking water at very low levels, mostly ng/L concentrations, suggesting that these compounds resisted removal through water treatment processes. Concerns have been raised regarding the effectiveness of common drinking water treatment technologies to remove these emerging contaminants. Adsorption processes were suggested to play an important role in the removal of PhACs and EDCs, based on the assumption that these compounds are similar to other conventional micropollutants such as pesticides in both physicochemical properties and concentration levels present in water. However, this remains to be demonstrated since the availability of adsorption data for PhACs and EDCs is extremely limited and their environmental concentrations are typically much lower than the ones for pesticides. The primary objective of this research was to evaluate in detail the removal of representative EDCs and PhACs at environmentally relevant concentrations by granular activated carbon (GAC) adsorption.
In the first stage of this study, EDCs (15) were screened separately from the PhACs (86) with two different sets of assessment criteria due to the different nature and the availability of information for these two groups of compounds. As a result, 6 EDCs and 12 PhACs were selected for further evaluation. Subsequently, a multi-residue analytical method based on gas chromatography/mass spectrometry (GC/MS) was developed for the simultaneous determination of the selected PhACs and EDCs. Two key analytical steps - solid phase extraction and derivatization - were systematically optimized using full factorial design and a central composite design, respectively. The statistical experimental design in combination with the concept of the total desirability was demonstrated to be an effective tool for developing a multi-residue analytical method. The application of the developed method to Grand River water, a local raw water source, and finished drinking water from this source indicated that PhACs such as naproxen, carbamazepine, salicylic acid, ibuprofen, and gemfibrozil, and EDCs such as estrone (E1) and nonylphenol mono-ethoxy carboxylate (NP1EC) were the most common contaminants. Based on these results, the quality of the analytical data, and the physicochemical properties relevant to the adsorption on activated carbon, two PhACs (naproxen, carbamazepine) and one EDC (nonylphenol (NP)) were finally chosen for the adsorption studies.
Adsorptions of the selected target compounds were evaluated on two types of activated carbon (coal-based Calgon Filtrasorb® 400 (F400) and coconut shell-based PICACTIF TE (PICA) by first investigating their isotherms at environmentally relevant concentrations (equilibrium liquid phase concentration ranging from 10 to 1000 ng/L). The single-solute isotherm data determined for both carbons showed that the relative adsorbabilities of the three target compounds were not in agreement with expectations based on their log Kow values. Overall, in this low concentration range, carbamazepine was most easily removed, and NP was least adsorbable. The adsorption of naproxen was negatively influenced by its dissociation in water. Comparison of single-solute isotherms on F400 carbon for the target compounds to those for other selected conventional micropollutants showed that naproxen and carbamazepine have generally comparable isotherms to 2-methylisoborneol (MIB) and geosmin. The isotherm tests in a post-sedimentation (PS) water from a full-scale plant demonstrated that the presence of background natural organic matter (NOM) significantly reduced the adsorption of all three target compounds, among which.NP was the least impacted compound. Based on the quantification of the direct competition using the ideal adsorbed solution theory (IAST) in combination with the equivalent background compound (EBC) approach, the minimum carbon usage rates (CURs) for removing 90% of the target compounds in PS water were calculated at two environmentally relevant concentrations (50 and 500 ng/L). This work confirmed that the percentage removal of the trace level target compound at a given carbon dosage was independent of the initial target compound concentration.
Isotherm experiments were conducted for the target compound on GACs preloaded with PS water for various time intervals (up to 16 weeks) at the Mannheim Water Treatment Plant (Region of Waterloo, ON, Canada). The results indicated that the adsorption of all target compounds were subject to significant negative impacts from preloading of NOM, albeit to different extents. Among the three target compounds, reduction in adsorption capacity for naproxen was most severe, followed by carbamazepine and then NP. The three target compounds followed quite different patterns of decrease in adsorption capacity with increasing preloading time, thus revealing different competitive mechanisms at work for the different compounds. For naproxen, the change in heterogeneity of the carbons due to preloading suggests that some pre-adsorbed NOM could not be replaced by naproxen. However, both direct competitive and pore blockage mechanisms could successfully explain the adsorption performance of naproxen and carbamazepine. The removal of NP even at prolonged preloading times could be explained by absorption or partitioning in the NOM matrix on the surface of, or inside the carbons.
The kinetic parameters for each target compound-virgin carbon pair were determined using the short fixed bed (SFB) approach based on the pore and surface diffusion model (PSDM). The SFB results and sensitivity analyses indicated that, under the very low influent concentration conditions, film diffusion (indexed as βL) exerts a much greater effect on breakthrough profiles than internal diffusion. The SFB tests on preloaded GACs showed that mass transport of all the target compounds decreased with increasing preloading time. Similar to the impact of preloading on adsorption capacity, naproxen was subject to the most deteriorative effect, followed by carbamazepine and then NP. In addition, potential mechanisms for the decay of the film diffusion coefficient with increased preloading time were discussed based on scanning electron microscope (SEM) images of virgin and preloaded GAC. Electrostatic interactions between the NOM/bio film formed on the preloaded carbon and dissociated naproxen may have contributed to the enhanced reduction in its film diffusion. Sensitivity analyses and subsequent calculations of the Biot numbers confirmed that film diffusion was also the predominant mechanism controlling the mass transport on preloaded carbon, in particular for naproxen. This suggests that the early breakthrough prediction of the target compounds at their environmentally relevant concentrations could be further simplified by only considering film diffusion and adsorptive capacity.
Kinetic and isotherm parameters were used as input for modeling using time-variable PSDM. It was found that the varying trends for Freundlich KF and 1/n, and βL could be generally depicted by a corresponding empirical model. Pilot scale treatability tests were performed for the target compounds which subsequently validated the time-variable PSDM results thus demonstrating its effectiveness and robustness to model GAC adsorber performance for PhAC and EDC removal at environmentally relevant concentrations. The time-variable approach was further improved by adjusting for NOM surface loading differences between the preloading and the pilot columns, which successfully compensated for the prediction errors at the early phase.
The validated NOM surface loading associated time variable PSDM was used to predict performances of hypothetical F400 and PICA full-scale adsorbers. Both adsorbers were expected to provide satisfactory performance in achieving 90% removals for the neutral target compounds (carbamazepine and NP). Naproxen was predicted to break through fast since both, capacity and kinetic parameters decay quickly due to carbon fouling by NOM and the physicochemical properties of this compound. Initial recommendations on the choice of adsorption process (GAC vs. PAC) for removing EDCs and PhACs can be made based on the comparison of carbon usage rates (CUR) which were calculated for a GAC adsorber using the validated improved PSDM and for PAC using the minimum applied dosages predicted by the IAST-EBC model.
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Redding, Adam Michael Cannon Fred S. "Examining granular activated carbon adsorption of organic contaminants from water endocrine disruptors / pharmaceuticals, methyl tert-butyl ether, and benzene /." 2008. http://etda.libraries.psu.edu/theses/approved/PSUonlyIndex/ETD-2799/index.html.
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Dias, Sandra Raquel da Silva. "Production of activated carbons by microwave pyrolysis of industrial wastes for the removal of pharmaceuticals from water." Master's thesis, 2018. http://hdl.handle.net/10773/24698.
Full textAbstract:
The presence of pharmaceuticals in water bodies, being biologically active compounds, have raised concerns due to the adverse effects in non-target organisms. With the conventional treatments, applied in the wastewater treatment plants (WWTPs), being inefficient for the removal of these contaminants, WWTPs are pointed out as the main source of pharmaceuticals into the environment. The use of adsorption, as an advanced treatment for the removal of pharmaceuticals from water, in particular by using activated carbons (ACs), has shown to be an easy-handling and cost-efficient process, without sub-products formation.
Since the production of ACs can be an expensive process, due to the high energy requirements and the use of expensive precursors, the alternative microwave (MW) pyrolysis of paper mill primary sludge (PS) can be a promising solution, contributing simultaneously for industrial waste valorisation. In the scope of this work, ACs were produced by MW pyrolysis of PS impregnated in KOH (activating agent) for 10 min at 800 W, washed with hydrochloric acid and sieved to obtain the fraction of particles with a size up to 180 μm. Different ACs were obtained by changing activating agent:precursor ratios, namely 0.5:1, 1:1 and 1.5:1. The produced ACs were physico-chemically characterised. In order to assess the performance of the produced ACs, batch adsorption experiments were performed with ultra-pure water to determine the adsorption percentages of the anti-epileptic carbamazepine (CBZ). The effect of AC dosage and the effect of contact time were also tested.
The obtained results have shown that, overall, the ACs produced with an activating agent:precursor ratio of 0.5:1 presented specific surface areas (SBET) between 773 and 1190 m2/g and high percentages of CBZ removed from ultra-pure water solutions, above 80 %, for AC dosages of 0.1 g/L and a contact time of 24 h. The lab-made ACs have shown a more developed porous structure than the reference commercial AC and comparable SBET. Nevertheless, under the same experimental conditions, different production batches resulted in ACs with different properties and performances, highlighting that further research work is required to optimise its production process, making it repeatable.Sendo os fármacos compostos biologicamente ativos, a sua presença nos recursos hídricos tem gerado preocupações devido aos efeitos adversos em organismos não-alvo. Sendo os tratamentos convencionais, aplicados nas estações de tratamento de águas residuais (ETARs), ineficientes para a remoção destes contaminantes, as ETARs são apontadas como a principal fonte de fármacos no meio ambiente. O processo de adsorção, enquanto tratamento avançado para a remoção de fármacos da água, em particular com o uso de carvões ativados (CAs), tem-se mostrado um processo de fácil aplicação e eficiente, sem formação de subprodutos. Como a produção de CAs pode ser um processo dispendioso, devido aos requisitos energéticos e ao uso de precursores de elevado custo, a alternativa pirólise em micro-ondas (MO) de lama primária (LP) da indústria papeleira pode ser uma solução promissora, contribuindo simultaneamente para a valorização de resíduos industriais. Neste trabalho, os CAs foram produzidos por pirólise em MO de LP impregnada com KOH (agente ativante) durante 10 min a 800 W, lavados com ácido clorídrico e crivados para obtenção da fração de partículas com dimensão inferior ou igual a 180 μm. Obtiveram-se diferentes CAs alterando as razões de agente ativante:precursor, nomeadamente 0.5:1, 1:1 e 1.5:1. Os CAs produzidos foram física e quimicamente caraterizados. No sentido de avaliar o desempenho dos CAs produzidos, realizaram-se testes de adsorção em descontínuo com água ultra-pura para determinar a percentagem de adsorção do anti-epilético carbamazepina (CBZ). O efeito da concentração de CA e o efeito do tempo de contacto também foram testados. Os resultados obtidos demonstraram que, de um modo geral, os CAs produzidos numa razão de 0.5:1 de agente ativante:precursor apresentaram áreas superficiais específicas (SBET) entre 773 e 1190 m2/g e elevadas percentagens de remoção de CBZ de soluções de água ultra-pura, acima de 80 %, para concentrações de CA de 0.1 g/L e tempos de contacto de 24 h. Os CAs produzidos em laboratório demonstraram ter uma estrutura porosa mais desenvolvida do que o CA comercial de referência e SBET comparáveis. Todavia, para as mesmas condições experimentais, diferentes lotes de produção originaram CAs com propriedades e desempenhos diferentes, denotando que mais trabalho de investigação deve ser investido de modo a otimizar o seu processo de produção, tornando-o repetível.
Mestrado em Estudos Ambientais
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"Adsorption of Pharmaceutically Active Compounds (PhACs) by Powdered Activated Carbon from Natural Water --Influence of Natural Organic Matter (NOM)." Diss., 2010. http://hdl.handle.net/10161/2510.
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Bolduc, Olivier R. "Monocouches peptidiques auto-assemblées et applications dans le domaine des biocapteurs de résonance de plasmon de surfaces." Thèse, 2011. http://hdl.handle.net/1866/6085.
Full textAbstract:
Ces travaux visent à étendre les applications de la résonance de plasmons de surface (SPR) L’objectif est d’offrir des outils diagnostics plus rapides, efficaces et simple d’utilisation pour diagnostiquer ou effectuer le suivi de conditions cliniques. Pour se faire, un nouveau type d’instrumentation SPR basé sur l’utilisation d’un prisme d’inversion (dove) a permis d’atteindre une limite de détection (LOD) de 10-6 unité d’indice de réfraction (RIU), une valeur comparable aux instruments commerciaux complexes tout en demeurant peu dispendieux, robuste et simple d’utilisation. Les travaux présentés dans cet ouvrage visent, dans un second temps, à réduire les interactions nonspécifiques (NSB) entre la surface des biocapteurs SPR et les composants de la matrice biologique complexe telles que: l’urine, le lysat cellulaire, le sérum et le sang. Ces dernières induisent des réponses empêchant l’utilisation de biocapteurs SPR en milieux complexes. Les acides aminés (AA) offrent une grande variété de propriétés physico-chimiques permettant la mise au point de monocouches auto-assemblées (SAM) aux propriétés diverses. Initialement, 19 des 20 acides aminés naturels ont été attachés à l’acide 3-mercaptopropionique (3-MPA) formant des SAMs peptidomimétiques. La quantité d’interactions nonspécifiques engendrées par ces différentes surfaces a été mesurée en exposant ces surfaces au sérum sanguin bovin complet variant de 400 ng/cm² jusqu’à 800 ng/cm². La détection à l’aide de ces surfaces de la β-lactamase (une enzyme responsable de la résistance aux antibiotiques au niveau μM) a démontré la possibilité d’employer ces surfaces pour bâtir des biocapteurs SPR. Des peptides de longueur allant de 2 à 5 résidus attachés à 3-MPA ont été synthétisés sur support solide. Cette étude a démontré que l’augmentation de la longueur des peptides formés d’AA résistants aux NBS accroit leur résistance jusqu’à 5 résidus. Le composé le plus performant de ce type (3-MPA-(Ser)5-OH) a permis d’atteindre 180 ng/cm². Cette valeur est similaire à celle des meilleures surfaces disponibles commercialement, notamment les surfaces de polyethylène glycol (PEG) à 100 ng/cm². Des surfaces de 3-MPA-(Ser)5-OH ont permis l’étalonnage de la β-lactamase et sa quantification directe dans un lysat cellulaire. La LOD pour ces biocapteurs est de 10 nM. Une troisième génération de surfaces peptidiques binaires a permis la réduction de la NSB jusqu’à un niveau de 23±10 ng/cm² une valeur comparable aux meilleures surfaces disponibles. Ces surfaces ont permis l’étalonnage d’un indicateur potentiel du cancer la metalloprotéinase-3 de matrice (MMP-3). Les surfaces formées de peptides binaires (3-MPA-H3D2-OH) ont permis la quantification directe de la MMP-3 dans le sérum sanguin complet. Une quatrième génération de surfaces peptidiques a permis de réduire davantage le niveau de NSB jusqu’à une valeur de 12 ± 11 ng/cm². Ces surfaces ont été modifiées en y attachant une terminaison de type acide nitriloacétique (NTA) afin d’y attacher des biomolécules marquées par six résidus histidines terminaux. Ces surfaces ont permis le développement d’une méthode rapide de balayage des ligands ciblant le « cluster of differenciation-36 » (CD36). L’étude d’électroformation des monocouches de peptide a permis de déterminer les conditions de formation optimales d’une couche de 3-MPA-HHHDD-OH permettant ainsi la formation de monocouches résistantes au NSB en moins de 6 minutes en appliquant un potentiel de formation de 200mV vs Ag/AgCl.The work presented in this thesis aims to extend the use of surface plasmon resonance (SPR) biosensors to generate more rapid, cost efficient and simple to use diagnostic tools to diagnose or follow serious medical conditions. This task required the development of a new SPR instrument that relies on an inversion prism (dove) and is able to reach a limit of detection (LOD) in the 10-6 refractive index unit (RIU) range, a value comparable to more complex commercial instruments. The developed SPR instrumentation is inexpensive, robust and very simple to manipulate. The other work presented in this thesis is based on reducing nonspecific interactions between the surface of SPR sensors and components in biological matrices such as urine, cell lysate, serum and whole blood. These nonspecific interactions induce SPR responses that have typically prohibited the use of SPR in these complex matrices. Amino acidshavebeen investigated for reduction of nonspecific binding (NSB) because they offer a wide variety of physico-chemical properties capable of tuning the physical properties of surfaces in a self-assembled monolayer (SAM) format. Initially, the attachment of one of 19 physiological 20 amino acids to 3-mercaptopropionic acid (3-MPA) allowed the formation of amino acid SAMs. Exposure of these surfaces to bovine serum revealed nonspecific interactions ranging from 400 ng/cm² to 800 ng/cm². Detection assays for β-lactamase (an enzyme produced by drug resistant bacteria at a micromolar level) demonstrated that the amino acid SAM is suitable for SPR biosensing. By using a solid phase approach, peptides were of 2 to 5 residues were synthesized to investigate NSB properties. The result of this study showed that adding amino acids decreased nonspecific interactions up to a peptide length of 5 amino acids. The best performing peptide, 3-MPA-(Serine)5-OH, resulted in low nonspecific adsorption of bovine serum proteins to a level of 180 ng/cm². This value is similar to nonspecific adsorption obtained under identical conditions for one of the best reported surfaces: polyethylene glycol-based SAMs at 100 ng/cm². The 3-MPA-(Serine)5-OH based SAM was used to calibrate β-lactamase, leading to its direct quantification in crude cell lysate. The detection limit for this analyte was 10 nM. A third generation of peptide, which is binary patterned, decreased significantly nonspecific adsorption to a level as low as 23 ± 10 ng/cm², a value comparable to the best surfaces known. This surface SAM allowed the calibration of matrix metalloproteinase-3 (MMP-3), a potential indicator of cancer. Direct quantification assays of MMP-3 in whole blood serum were achieved with the binary patterned peptides developed. The LOD for MMP-3 was 0.2nM over a 50 nM linear domain. A fourth generation of peptide based surfaces was developed, reducing the level of nonspecific adsorption of blood serum proteins to 12 ± 11 ng/cm2. These new surfaces were modified to attach His-tagged biomolecules enabling rapid screening of small ligands targeting the Cluster of differentiation-36 (CD36). Finally, the electroformation of peptide monolayers was studied to determine the optimal conditions needed to form an ultralow biofouling surface. It was demonstrated that the difference in potential applied during the formation of a peptide based layer influences the kinetics of formation and the arrangement of this layer. An optimal layer of 3-MPA-HHHDD-OH could be obtained in less than 6 min by applying a potential of 200mV vs Ag/AgCl to the SPR sensor.
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Pereira, Diogo Esteves. "Functionalization of waste-derived activated carbon for the removal of carbamazepine from water." Master's thesis, 2019. http://hdl.handle.net/10773/27903.
Full textAbstract:
Adsorption of pharmaceuticals onto activated carbons constitutes one of the most promising technologies for the removal of these persistent
contaminants from water. Production of activated carbon from wastes provides an alternative and eco-friendlier option to commercial nonrenewable-
based activated carbon and simultaneously contributes to the valorisation of industrial and agricultural biomass residues that enforces the
principles of a circular economy. However, the application of powdered activated carbon in continuous treatment systems is hampered by the
difficulty in recovering the material from the treated aqueous phase. The loading of magnetic iron oxide nanoparticles onto the surface of the
activated carbon can facilitate the recovery of the adsorbent by the application of an external electromagnetic field or a permanent magnet,
avoiding expensive and complex processes such as filtration or coagulation. In this work, magnetic activated carbon (MAC) was produced via two
synthesis pathways. Waste-based powdered activated carbon (WPAC) produced from primary paper mill sludge (PS) was used as precursor in both routes. The in-situ route involves the coprecipitation of magnetic iron oxides onto the surface of WPAC. The ex-situ route involves the separate
production of magnetic iron oxide particles, subsequently added in suspension to WPAC, at controlled pH. The produced materials were physically and chemically characterized (total organic carbon, Fourier transform infrared spectroscopy, specific surface area, pore morphology, point of zero charge, vibrating sample magnetometer, scanning electron microscopy imaging and X-Ray diffraction) and subject of preliminary adsorption tests for the removal of the anti-epileptic carbamazepine (CBZ) from ultrapure water. Best materials were selected (in-situ MAC2-MP1 and ex-situ MACX1-MP1), and kinetic and equilibrium studies were performed in both ultrapure water and real effluent collected from a local wastewater treatment plant. Kinetic studies revealed that equilibrium was achieved at around 30-45 min for both materials in both matrices. Maximum adsorption capacities for CBZ in ultrapure water were 90 ± 4 mg g-1 and 121 ± 5 mg g-1, for MAC4-MP1 and MACX1-MP1, respectively. In real effluent maximum adsorption capacities were lower for both materials, 60 ± 3 mg g-1 and 78 ± 2 mg g-1 for MAC4-MP1 and MACX1-MP1, respectively. Both materials presented lower adsorption capacities than the non-magnetic WPAC. However, magnetization was successfully achieved in both cases and the materials proved to be competitive with a non-magnetic commercial PAC in ultrapure water, which indicates to a potential application in continuous water treatment systems.A adsorção de fármacos a carvões ativados é uma das tecnologias mais promissoras para a remoção destes compostos persistentes da água. A produção de carvões ativados a partir de resíduos de biomassa constituí uma alternativa mais barata e ecológica aos carvões ativados produzidos a partir de precursores não-renováveis, permitindo a valorização de resíduos industriais e agrícolas e aplicando os valores de uma economia circular. No entanto, a aplicação de carvões ativados em pó em sistemas de tratamento em contínuo é inibida pela dificuldade de separação do material das águas residuais tratadas. O carregamento de nanopartículas magnéticas de óxido de ferro na superfície do carvão ativado facilita a recuperação pela aplicação de um campo eletromagnético externo ou um íman permanente, evitando processos dispendiosos como a filtração ou a coagulação. Neste trabalho, carvões ativados magnéticos (MAC) foram produzidos por duas vias. Um carvão ativado derivado de resíduos (WPAC) produzido a partir de lamas primárias da indústria papeleira (PS) foi usado como precursor. A via de produção in-situ envolve a coprecipitação de óxidos de ferro magnéticos diretamente na superfície do WPAC. A via ex-situ envolve a síntese em separado dos óxidos de ferro magnéticos e subsequente adição ao WPAC em suspensão a pH controlado. Os materiais produzidos foram alvo de caracterização física e química (carbono orgânico total, espectroscopia de infravermelho com transformada de Fourier, área superficial específica, morfologia dos poros, ponto de carga zero, vibrating sample magnetometer, microscopia de varrimento eletrónico e difração de raios-X) e sujeitos a testes de adsorção preliminares para a remoção do antiepilético carbamazepina (CBZ) de água ultrapura. Os melhores materiais foram selecionados (in-situ MAC4-MP1 e ex-situ MACX1-MP1) e sujeitos a testes de cinética de adsorção e de isotérmica, tanto em água ultrapura como em efluente real recolhido numa ETAR local. De acordo com os estudos cinéticos, ambos os materiais atingiram o equilíbrio entre os 30-45 min em ambas as matrizes. As capacidades máximas de adsorção em água ultrapura foram de 90 ± 4 mg g-1 e 121 ± 5 mg g-1, para MAC4-MP1 e MACX1-MP1, respetivamente. Em efluente real as capacidades máximas de adsorção foram inferiores para ambos os materiais, 60 ± 3 mg g-1 e 78 ± 2 mg g-1 para MAC4-MP1 e MACX1-MP1, respetivamente. Ambos os materiais apresentaram capacidades de adsorção inferiores ao WPAC. Contudo, a sua magnetização foi atingida com sucesso e os materiais provaram ser competitivos com um PAC não-magnético comercial em água ultrapura, o que indica a sua potencial aplicação em sistemas de tratamentos de água em contínuo.
Apoio financeiro da FCT e COMPETE2020 no âmbito do projeto de investigação WasteMAC - POCI-01-0145FEDER-028598.
Mestrado em Biotecnologia
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Lopes, David Terreiros da Fonseca. "Aerogéis compósitos de nanotubos de carbono/sílica para remediação ambiental." Master's thesis, 2019. http://hdl.handle.net/10316/87920.
Full textAbstract:
Dissertação de Mestrado Integrado em Engenharia Química apresentada à Faculdade de Ciências e TecnologiaO principal objetivo desta dissertação de mestrado foi incorporar nanotubos de carbono (CNTs) em aerogéis de sílica para obtenção de materiais compósitos com boas propriedades de adsorção. Metiltrimetoxissilano (MTMS) e (3-aminopropil) trimetoxissilano (APTMS) foram utilizados como precursores de sílica, os quais, em diferentes proporções molares e utilizando a metodologia sol-gel, levaram à formação de aerogéis compósitos de CNTs-sílica.O surfactante utilizado foi escolhido entre brometo de hexadeciltrimetilamónio (CTAB), dodecil sulfato de sódio (SDS) e polietilenoglicol (PEG). Quando a síntese foi realizada com PEG, não foi obtido um gel, no entanto, o uso dos outros dois surfactantes produziu monólitos que não apresentaram diferenças significativas nos valores da massa volúmica bulk. Em relação ao tempo de gelificação, o CTAB apresentou os melhores resultados, com menor tempo de gelificação, o que é favorável para evitar a sedimentação dos CNTs na suspensão.O próximo parâmetro estudado foi o método de agitação e, embora a agitação mecânica proporcionasse menor massa volúmica bulk, o banho de ultrassom permitiu uma melhor dispersão dos CNTs na solução. Um estudo sobre a necessidade de uma etapa de lavagem para remover o surfactante dos géis foi também realizado. Comparando os resultados para a mesma formulação, com e sem lavagem, foi possível concluir que esta etapa foi fundamental, permitindo uma melhoria significativa na massa volúmica bulk, levando a uma redução de 5 a 10 kg m-3. A análise termogravimétrica confirmou que a etapa de lavagem removeu praticamente todo o surfactante da estrutura dos materiais.Os aerogéis com diferentes proporções de precursores (100% MTMS, 90% MTMS/10% APTMS e 80% MTMS/20% APTMS) foram caracterizados química, física e microestruturalmente. As amostras com 100% de MTMS apresentaram menores valores de massa volúmica bulk. A presença de grupos amina levou a um aumento em termos de tamanho dos poros, mas uma redução da área superficial específica. As técnicas de microscopia permitiram a visualização da microestrutura dos materiais, sendo visíveis grandes partículas secundárias, além de ser possível verificar a matriz de sílica à volta dos CNTs.Os testes de adsorção revelaram que a presença de CNTs levou a uma ligeira melhoria nas propriedades de adsorção dos adsorventes. Em relação aos compostos orgânicos voláteis (VOC), para os melhores materiais, com xileno e benzeno, foram obtidos elevadas percentagens de remoção (para benzeno superior a 80% e para xileno maior que 90%), enquanto para fenol foi removido apenas no máximo 30%. Para os fármacos, os melhores resultados foram obtidos para o naproxeno, com percentagens de remoção de até 96,9%, enquanto para a amoxicilina o melhor resultado de remoção foi em torno de 67%. Num estudo mais aprofundado do processo de adsorção, foi possível concluir que a presença de CNTs melhorou os parâmetros cinéticos (maior velocidade de adsorção), assim como os parâmetros das isotérmicas (maior afinidade entre a fase líquida e a fase sólida).
The main goal of this master’s dissertation was to incorporate carbon nanotubes (CNTs) in silica aerogels with the aim of obtaining composites with good adsorption properties. Methyltrimethoxysilane (MTMS) and (3-aminopropyl) trimethoxysilane (APTMS) were used as silica precursors, which, in different molar proportions and using the sol-gel methodology, led to the formation of CNTs-silica aerogel composites. The used surfactant was chosen among hexadecyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG). When the synthesis was performed with PEG, the gelation did not occur, however, the use of the other two surfactants produced aerogel monoliths that did not show significant differences in the values of bulk densities. Regarding the gelation time, CTAB showed the best results, with lower time, which is favorable to avoid CNTs sedimentation in the suspension. The next studied parameter was the agitation method and, even though the mechanical stirring provided lower bulk density, the ultrasound bath allowed a better CNTs dispersion in the solution. A study concerning the need of a washing step to remove the surfactant was also accomplished. Comparing the results for the same formulation, with and without washing, it was possible to conclude that this step was crucial, and allowed a significant improvement in the bulk density, leading to a decrease of 5 to 10 kg m-3. The thermogravimetric analysis confirmed that the washing step removed practically all the surfactant from the materials structure.The aerogels with different molar ratio of precursors (100% MTMS, 90% MTMS/10% APTMS and 80% MTMS/20% APTMS) were characterized chemical, physical and microstructurally. The samples with 100% MTMS presented lower values of bulk density. The presence of amine groups led to an increase in terms of pore size and a reduction regarding the specific surface area. The microscopy techniques allowed the visualization of the materials microstructure, showing large secondary particles, besides enabling the verification of the silica matrix around the CNTs. The adsorption tests revealed that the presence of CNTs led to a slight improvement in the adsorption properties of the adsorbents. Regarding volatile organic compounds (VOC), for the best materials, with xylene and benzene, high removal percentage rates were obtained (for benzene superior to 80% and for xylene higher than 90%), while for phenol a maximum of 30% was removed. For the pharmaceuticals, the best results were obtained for naproxen, with removal rates of up to 96.9 %, while for amoxicillin the best result was around 67% of removal. In a more in-depth study of the adsorption process, it was possible to conclude that the presence of CNTs improved the kinetic parameters (higher adsorption velocity), as well as the parameters of the adsorption isotherms (higher affinity between liquid phase and solid phase).