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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Desenvolvimento de filmes de gelatina contendo zeólita clinoptilolita impregnada com íons prata e avaliação das propriedades antimicrobianas

Hubner, Patricia January 2017 (has links)
Curativos utilizados no tratamento de feridas crônicas e queimaduras devem apresentar carac terísticas antimicrobianas. Sabe-se que compostos de prata são utilizados há muito tempo como antissépticos, mas apresentam alguns problemas relacionados ao modo de liberação. A fim de controlar essa liberação, os íons Ag+ podem ser imobilizados em suportes, como por exemplo, zeólitas, que por sua vez devem estar dispersas no filme que é utilizado como curativo. Nesse contexto, este trabalho tem como objetivo o desenvolvimento e a caracterização de filmes à base de gelatina, adicionados de zeólita clinoptilolita impregnada com íons prata e a avaliação das propriedades antimicrobianas, visando à aplicação no tratamento de ferimentos. Filmes com 5,7 e 10% (m/v) de gelatina e 0, 5, 10, 15, 20 e 25% (v/v) de glicerol foram produzidos e caracterizados quanto à espessura, teor de umidade, capacidade de absorção de água (CAA), caráter hidrofílico, propriedades mecânicas, permeabilidade ao vapor de água (PVA), fluxo de permeação de vapor de água (FPVA), morfologia por microscopia eletrônica de varredura (MEV) e espectroscopia de infravermelho por transformada de Fourier (FTIR). Com base nas características determinadas, foi possível selecionar três formulações para incorporação das zeólitas (10% de gelatina e 15, 20 e 25 % de glicerol). A zeólita comercial clinoptilolita foi caracterizada e impregnada com íons Ag+. Na sequência, por meio de um ensaio antimicrobiano preliminar, foi definido que as zeólitas seriam adicionadas aos filmes nas concentrações de 0,5; 1 e 2 % (m/v). Os filmes à base de gelatina com zeólitas foram caracterizados pelos mesmos ensaios citados e também por análise tennogravimétrica (TGA), calorimetria exploratória diferencial (DSC) e quantiticação de íons prata por espectrometria de absorção atômica com chama (FAAS). Através da avaliação antimicrobiana qualitativa, percebeu-se que a ação antimicrobiana é decorrente da presença dos íons Ag+, porém não foram identificadas diferenças expressivas entre o tamanho dos halos de inibição formados para as diferentes concentrações de clinoptilolita-Ag. Através do ensaio microbiológico quantitativo verificou-se que não havia carga bacteriana na solução onde o filme estava imerso. Os resultados obtidos mostram que os filmes desenvolvidos neste estudo têm potencial para serem aplicados como curativos, atuando como antimicrobiano, auxiliando, desta forma, na cicatrização dos ferimentos. / Dressings used in treatment of bums and chronic wound must present antimicrobial characteristics. It is known that silver compounels are used for long time as antiseptics, but they have some problems related to release mode. To control this release, Ag+ ions may be immobilized in supports, as zeolites, that must be disperseel in the film used as wound dressing. In this sense, this work objectives the development and characterization of gelatin based-films added of clinoptilolite zeolite impregnated with silver ions and antimicrobial properties evaluation, aiming the application in wound treatment, as burns, for example. Films with 5,7 anel 10% (w/v) of gelatin anel 0, 5, 10, 15, 20 anel 25 % (v/v) of glycerol were produced and characterized by the thickness, moisture content, water absorption capacity (CAA), hydrophilic character, mechanical properties, water vapor permeation (PVA), water vapor permeation flux (FPVA), morphology by scanning electron microscopy (MEV) and Fourier transform infrared spectroscopy (FTIR). Based on the determined characteristics, it was possible select three formulations for zeolites incorporation (10% of gelatin and 15, 20 and 25 % of glycerol). Commercial clinoptilolite zeolite was characterized and impregnated with Ag+ ions. Subsequently, by a preliminary antimicrobial assay, it was defined that the zeolites would be added to the films in the concentrations of 0.5, 1 and 2 % (w/v). Gelatin based films with zeolites were characterizeel by the same assays cited and, also, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and silver ions quantification by flame atomic absorption spectroscopy (FAAS). Characterization tests demonstrated that the zeolite concentration of 0.5% resulted in films with properties more suitable for wound dressing application. By the qualitative antimicrobial evaluation, it was noticed that the antimicrobial action is due to the Ag+ ions, but no significant differences between the size of the inhibition halos formed were observed for the different concentrations of clinoptilolite-Ag. By the quantitative antimicrobial evaluation, it was found that there was no bacterial load in the solution where the film was submerged. The results show that the films developed in this stuely have potential to be applied as wound dressings, acting as an antimicrobial, thus helping the wound healing.
32

Utilização da clinoptilolita-heulandita como coadjuvante aos moduladores nutricionais na alimentação de frangos de corte / Use of the clinoptilolita-heulandita as supporting to the modulators of nutritional in the feeding of poultry

Arruda, Polyana Ferreira 24 March 2006 (has links)
Foram utilizados 342 pintos de corte de um dia de idade macho da linhagem Cobb 500, distribuídos aleatoriamente em três tratamentos experimentais com seis repetições, em um galpão experimental dividido por boxes, sendo 19 aves por unidade experimental, com duração de 46 dias, para avaliar o uso da clinoptilolita-heulandita associada aos moduladores de crescimento. Foi utilizado uma dieta basal isonutritiva à base de milho e farelo de soja como grupo controle, e a partir desta foram adicionados dois níveis de clinoptilolita-heulandita (0 e 2,5%) e dois níveis de flavomicina (0 e 0,04%). No 29º dia de idade, duas aves por unidade experimental foram sacrificadas de modo a serem coletadas as tíbias direitas para determinação de cinzas, cálcio e fósforo ósseas. Também foram coletados os aparelhos intestinais das aves para observação de lesões de Eimeria máxima. Não foram observadas diferenças entre os tratamentos para o peso final, ganho de peso e conversão alimentar. Ao se avaliar as lesões de Coccidiose causadas por Eimeria máxima, o score de lesão foi significativamente maior para o grupo controle, seguido do tratamento com clinoptitolita-heulandita. / Three hundred and forty two male Cobb 500 one-day-old chicks were conducted on a three treatments experiment design with 6 replicates each treatment during the period of 46 days to avaliate the addition of clinoptilolite-heulandite associated with growth modulators in feed. Two levels of clinoptilolite-heulandite (0 and 2.5%) and two levels of flavomicin (0 and 0.04%) were added to a standard corn-soybean meal diet, the control group, to meet or exceed the nutrients required. Two birds from each treatment were sacrificed on day 29 and collected the right tibias to determine ash, calcium and phosphorus bone. The intestine was collected to observe the gross lesions of Eimeria maxima. There were observed no difference between the treatments for body weight, body weight gain and feed conversion. The coccidiosis score lesions caused by Eimeria maxima showed higher lesions on control group, followed by clinoptilolite-heulandite.
33

Comparison of Functional Porous Organic Polymers (POPs) and Natural Material Zeolite for Nitrogen Removal and Recovery from Synthetic Urine

Zhang, Yan 19 March 2018 (has links)
Urine comprises around 1% of domestic sewage volume but holds 80% of total nitrogen. Source separation is a sustainable way to wastewater management than traditional way due to low energy cost and preventing certain pollutants into wastewater treatment plants. Currently, removing and recovering nitrogen from source-separated urine has attracted more and more interests. Of them, ion exchange was used for removal and recovery of nitrogen in the form of ammonia from synthetic urine for potential application as a fertilizer in agriculture. No previous research studies were conducted to investigate the removal and recovery of nitrogen from hydrolyzed urine by ion exchange using POPs (porous organic polymers). So this study focused on evaluating the performance of POPs and comparing with clinoptilolite in synthetic hydrolyzed urine in terms of adsorption capacity (isotherm), adsorption rate (kinetics), regeneration rate, and cost. The ammonium removal from hydrolyzed urine using POPs was rapid with a high capacity of 68.03 mg/g than clinoptilolite (15.36 mg/g), and the regeneration efficiency of clinoptilolite and POPs can achieve 91% and 95.3%, respectively based single time use result. Although POPs had the better performance at one time use and multiple times use, it also had high materials cost. Additionally, the capacity of POP was estimated using the integrated ion exchange regeneration process model as 30.24 mg/g and 28.65 mg/g on cycle 10 and cycle 24, respectively. The regeneration efficiency of POPs was predicated as 45.4% and 38.4% in cycle 10 and cycle 24, respectively. The predicted capacity decreased with the number of cycles, but remained at about 55% of virgin POPs after 24 cycles, indicating POPs can maintain good performance after multiple reuses than clinoptilolite.
34

Brine treatment using natural adsorbents

Mabovu, Bonelwa January 2011 (has links)
The current study investigated application of natural adsorbents in brine treatment. Brines are hypersaline waters generated in power stations and mining industries rich in Mg2+, K+, Ca2+, Na+, SO4 2- , Cl- and traces of heavy metals, thus there is a need for these brines to be treated to recover potable water and remove problematic elements. Natural adsorbents have been successfully used in waste water treatment because of their high surface area and high adsorptive properties when they are conditioned with acid or base. The investigation of pH showed that natural adsorbents did not perform well at low pH of 4 and 6. The adsorbents were able to work efficiently at the natural pH of 8.52 of the brine solution. These results show that natural adsorbents hold great potential to remove cationic major components and selected heavy metal species from industrial brine wastewater. Heterogeneity of natural adsorbents samples, even when they have the same origin, could be a problem when wastewater treatment systems utilizing natural clinoptilolite and bentonite are planned to be developed. Therefore, it is very important to characterize the reserves fully in order to make them attractive in developing treatment technologies.
35

Exchanges Of Strontium On Clinoptilolite Zeolite

Gul, Ozkan 01 November 2003 (has links) (PDF)
ABSTRACT EXCHANGES OF STRONTIUM ON CLINOPTILOLITE ZEOLITE G&Uuml / L, &Ouml / zkan MS, Department of Chemical Engineering Supervisor: Prof. Dr. Hayrettin Y&uuml / cel November 2003, 110 Pages Sr-90 and Cs-137, nuclear fission products, are the major sources of medium-level radioactive waste which must be decontaminated. Inorganic ion exchangers are the preferred materials to eliminate radioisotopes from aqueous nuclear waste because of their high selectivity, radiation and thermal stability, low cost and likely compatibility with cement containment. Clinoptilolite and other zeolites are widely used in nuclear industry for the removal of radioisotopes from aqueous nuclear waste. In this study, the performance of local clinoptilolite zeolite from G&ouml / rdes region has been investigated so as to determine the conditions under which it can be used effectively in the column for strontium and cesium removal. It was found that under different loading conditions, breakthrough capacity varied from 0 to 0.4078 meq/g for strontium removal, breakthrough capacity varied from 0.1178 to 0.7800 meq/g for cesium removal. It was also determined that the increase of the flow rate reduced the exchange capacity of the bed. Effect of cationic form of the zeolite (Na-CLI: Sodium form of clinoptilolite and Original-CLI: Original form of clinoptilolite) on the breakthrough capacity was also searched. It was observed that Na-CLI performed much better for the removal of strontium and cesium with respect to its original form. In addition, effect of presence of calcium in the feed solution on the breakthrough capacity was investigated and it was found that presence of calcium in the feed solution makes strontium removal essentially impossible, in the case of cesium, presence of calcium in the feed solution decreases breakthrough capacity significantly.
36

Exchange Of Cadmium And Lead On Sodium Clinoptilolite Zeolite

Isler, Hakan Murat 01 May 2010 (has links) (PDF)
Heavy metal ions, such as cadmium and lead, should be removed from wastewaters to prevent bioaccumulation. Among many other separation processes, one of the alternatives is ion exchange involving a low cost packing material, clinoptilolite. Clinoptilolite is a natural zeolite and contains exchangeable cations such as Na+, K+, Mg2+, and Ca2+ in its structure. Aim of this study is to determine binary and multicomponent ion exchange behaviors of sodium enriched form of G&ouml / rdes clinoptilolite for lead and cadmium ions. For this purpose, Pb+2 &ndash / Na+, Cd+2 &ndash / Na+ binary and Pb+2 &ndash / Cd+2 &ndash / Na+ ternary systems were investigated in column operations for concentrations between 0.005 to 0.02 N and flow rates between 5 to 20 mL/min at 25 &amp / #730 / C. For determination of optimum particle size, 5/6, 8/10, 14/18, 20/30, 35/60, and 70/140 ASTM E-11 standard mesh ranges were tested and the optimum particle size, under the experimental conditions was found as 35/60. Furthermore, although the clinoptilolite has a theoretical ion exchange capacity of 2.14 meq/g based on its aluminum content, under experimental conditions maximum exchange level was determined as 1.08 meq/g. For binary and ternary experiments, it is observed that the clinoptilolite has affinity for both Pb2+ and Cd2+ ions. However, clinoptilolite has greater affinity to Pb2+ than Cd2+ ion. Therefore, selectivity sequence was determined as Pb2+&gt / Cd2+&gt / Na+. Additionally, for column studies, flow rates less than 10 mL/min and influent concentrations up to 0.01 N, sodium enriched form of G&ouml / rdes clinoptilolite holds great potential to remove Pb2+ and Cd2+ ions from wastewaters.
37

Ammonium And Lead Exchange In Clinoptilolite Zeolite Column

Bahaalddin, Ahmad Dh. 01 January 2011 (has links) (PDF)
Wastewaters resulted from anthropogenic influence can encompass a wide range of potential contaminants and concentrations. There are numerous procedures that can be used to clear out wastewaters depending on the type and extent of contamination, however / disposal of pollutants from wastewaters in industrial scale is a difficult and costly problem. In this study, the use of ion exchange theory utilizing natural Turkish clinoptilolite zeolite from G&ouml / rdes-Manisa as ion exchange resins in down-flow column mode is investigated. The clinoptilolite with particle size range of 0.25-0.50 mm is used in the removal of lead Pb2+ and ammonium NH4+ ions from aqueous solutions. The aim of the study is to set up the conditions under which clinoptilolite may be used in an economical and efficient approach in the removal process. Experiments were divided into two sets: binary studies, and ternary studies, and the effects of conditioning clinoptilolite with NaCl solution, flow rate, and initial concentration of the solutions on the removal behavior were investigated. In binary studies, results showed that increasing the loading volumetric flow rate resulted in decreasing the breakthrough capacity and the column efficiency, while the total capacity remained constant. The maximum total capacity was determined as 1.16 meq/g of zeolite for NH4+, and 1.1 meq/g of zeolite for Pb2+ and these values were close to each other and to the sodium content of Na-form of pretreated clinoptilolite (1.16 meq/g of zeolite). In addition, by decreasing the initial contaminant concentration, an increase in breakthrough capacity and column efficiency was observed. In ternary studies, the results showed that the removal of Pb2+ and NH4+ ions are dependent on the flow rate, in which at moderately low flow rate, a higher ion exchange capacity is yielded. That was explained as at higher flow rates, the retention time was insufficient for the ion exchange process to take place completely between clinoptilolite and lead and ammonium ions. Thus, a competition between Pb2+ and NH4+ ions for the exchange sites on clinoptilolite was observed and this competition was in favor of lead ions. Consequently, it was observed that the clinoptilolite zeolite has affinity for both Pb2+ and NH4+ ions. However, the affinity of clinoptilolite for lead ions is higher than that for ammonium ions. Therefore, the cations selectivity for clinoptilolite according to their affinity is determined as the following sequence: NH4+ &gt / Pb2+ &gt / Na+.
38

Brine treatment using natural adsorbents

Mabovu, Bonelwa January 2011 (has links)
The current study investigated application of natural adsorbents in brine treatment. Brines are hypersaline waters generated in power stations and mining industries rich in Mg2+, K+, Ca2+, Na+, SO4 2- , Cl- and traces of heavy metals, thus there is a need for these brines to be treated to recover potable water and remove problematic elements. Natural adsorbents have been successfully used in waste water treatment because of their high surface area and high adsorptive properties when they are conditioned with acid or base. The investigation of pH showed that natural adsorbents did not perform well at low pH of 4 and 6. The adsorbents were able to work efficiently at the natural pH of 8.52 of the brine solution. These results show that natural adsorbents hold great potential to remove cationic major components and selected heavy metal species from industrial brine wastewater. Heterogeneity of natural adsorbents samples, even when they have the same origin, could be a problem when wastewater treatment systems utilizing natural clinoptilolite and bentonite are planned to be developed. Therefore, it is very important to characterize the reserves fully in order to make them attractive in developing treatment technologies.
39

Klinoptilolito panaudojimas skirtingų veislių šunų šėrimui / Usig of clinoptilolite for feeding dogs of different breeds

Kaušinytė, Rasa 05 March 2014 (has links)
Darbo tikslai: įvertinti klinoptilolito įtaką didelių, vidutinių ir mažų veislių šunims: maisto medžiagų pasisavinamumui, sveikatingumui, virškinamojo trakto mikrofloros kitimui. Darbo uždaviniai: 1. atlikti mokslinius ūkinius bandymus su skirtingų veislių šunimis prieš pradedant vartoti klinoptilolito preparatą ir atskirais laikotarpiais; 2. nustatyti ėdalo ir jame esančių maisto medžiagų suvartojimo kiekius atskirais augimo tarpsniais; 3. įvertinti klinoptilolito preparato sudėtį ir poveikio tendencijas; 4. nustatyti išskiriamų išmatų kiekius ir jų cheminę sudėtį; 5. paskaičiuoti maisto medžiagų pasisavinamumą organizme; 6. įvertinti sveikatos būklę. Praktinio darbo reikšmė: atliktais bandymais buvo parodytas klinoptilolito teigiamas poveikis organizmui: sveikatingumui, maisto medžiagų pasisavinamumui ir taršos aplinkai. 2012-2013 metais, tyrimas buvo atliktas su šiomis šunų veislėmis: jorkšyro terjerų patinais ir kalėmis, anglų kokerspanielių kalėmis ir vokiečių aviganių patinais. Mokslinis ūkinis bandymas trūko 6 mėn. Tyrimai buvo atliekami skirtinguose veislynuose. Rezultatai yra apibendrinami nustatant: šunų svorio kitimus atskirais laikotarpiais, ėdalo praėjimo greitis per virškinimo traktą, išmatų kiekių nustatymas, svorio skaičiavimas bandymo pradžioje ir pabaigoje ir ėdalo suvartojimo kiekiai. Mažų veislių šunų tiriamoji grupė suvartojusi sauso ėdalo su klinoptilolitu per parą 60,1 g, o kontrolinė grupė 62,8 g, išskyrė išmatų 44,3 g tiriamoji grupė ir 46,8 g... [toliau žr. visą tekstą] / Aims of the study: to evaluate the efficacy of clinoptilolite to overal wellness, changes made to GI tract microflora and digestibility of food substances for large, middle and small sized dogs. Objectives: 1. to perform household experiments with dogs of different breed before giving clinoptilolite and during various periods; 2. to evaluate consumption of food and different food substances during different growing periods; 3. to assess clinoptilolite’s composition and tendencies of effect; 4. to determine the amount and chemical composition of excreted feces; 5. to evaluate the consumption of food substances; 6. to assess the overall health. Significance of the study: the positive effect of clinoptilolite for wellness, consumption of food and effect for environment was proven by our experiments. In 2012-2013 year the experiment was conducted with both genders of Yorkshire Terriers, females of English Cocker Spaniel and German shepherd males. Household study took six months and experiments were made in different breeding grounds. Results were concluded by evaluating differences in body weight of dogs during different time periods, measuring amount of feces excreted, speed of food transition through the entire gastrointestinal tract, measuring body weight in the start and in the end of the experiment and measuring amount of consumed food. Experiment groups: small breed dogs consumed different amount of foods. Experiment group consumed 60,1 g of food with additive, and... [to full text]
40

Decolorization Of Synthetic Dye Solutions By Using Basaltic Tephra And Clinoptilolite

Duygulu, Yusuf Bahadir 01 July 2004 (has links) (PDF)
Discharge of colored effluents without decoloration originated from textile industries may cause serious problems in the receiving environments. In this study, natural materials that are basaltic tephra and clinoptilolite were used to remove various dyestuffs used in the textile industry. Those materials are cheap and available in large quantities in Turkey. The investigation of adsorption of basic, acidic and reactive dyes on these materials is the objective of this study. During preliminary experiments it was seen that adsorption equilibrium was reached in about 2 days. In adsorption experiments, in order to obtain adsorption isotherms, a fixed amount of adsorbent and 100 mL dye solutions of different concentrations were placed in glass bottles which were shaken at 200 rpm and 25&plusmn / 2oC for 2 days. Then, samples were filtered and the equilibrium concentrations of dyestuffs in the solutions were determined by using spectrophotometer at appropriate wavelength corresponding to the maximum absorbency. After equilibrium concentrations of the solutions were obtained, Langmuir and Freundlich adsorption isotherm constants were calculated for the adsorbents used in this study. The removal efficiencies for cationic basic dyes are higher than those for anionic acidic and reactive dyes with the natural materials. Therefore, modification of surface properties of natural materials with a cationic surfactant was considered to increase the removal efficiencies of those for anionic dyes. After modification of the surface properties, adsorption capacities of adsorbents for anionic dyes were higher than those of natural materials. Finally, the adsorption capacity of activated carbon for the same dyes was determined to compare with that of natural and modified materials. The results showed that the adsorption of dyes on adsorbents used in this study fitted nicely the Langmuir Isotherm Equations.

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