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Etude systématique des complexes Znq+Imn (où q = 0, 1, 2; n = 1 – 4) / Systematic study of Znq+Imn (where q = 0, 1, 2; n = 1 – 4) complexesBoussouf, Karim 14 December 2016 (has links)
Le but de ce travail est d'examiner la capacité des fonctionnelles M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3 et M11 avec ou sans inclusion de la correction de dispersion de Grimme (D3) pour la description précise et simultanée des complexes organométalliques de taille moyenne et leur utilisation dans l’étude de la structure d’équilibre, la stabilité, la spectroscopie et la liaison chimique (covalente, transfert de charge et Van der Waals (vdWs). Ceci a été fait par une comparaison directe des résultats obtenus par ces fonctionnelles avec ou sans inclusion de la correction de dispersion de Grimme (D3) et ceux issus des méthodes explicitement corrélées (R)CCSD(T)-F12 et (R)MP2-F12. Nous avons démontré que les fonctionnelles M05-2X+D3 et PBE0+D3 en connection avec la base 6-311++G(d,p) sont les fonctionnelles de choix. Ceci a été illustré à travers une étude systématique des complexes Zn+qIm (q=0, 1,2) qui jouent un rôle important en chimie, en biologie, en environnement et en industrie. Pour les complexes Zn+qIm (q=0, 1, 2), nous avons comparé les résultats obtenus aux niveaux M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3, M11 et ceux issus des méthodes explicitement corrélées (R)CCSD(T)-F12 et (R)MP2-F12. A travers ces comparaisons, nous avons établi que la capacité et la fiabilité de la fonctionnelle M05-2X(+D3) pour la décrire précisément les interactions covalentes et non-covalentes entre Znq+ et Im car elle donne des résultats en excellent accord avec ceux issus des méthodes ab initio hautement corrélées. Les fonctionnelles PBE0 et M11 peuvent être aussi utilisées pour les applications.Par la suite, nous allons profiter de la haute performance des fonctionnelles M05-2X et PBE0 avec ou sans inclusion de la correction de dispersion de Grimme (D3) en connection avec la base 6-311++G(d,p) pour étudier la structure d’équilibre, la stabilité, la spectroscopie et la liaison chimique (covalente, transfert de charge et van der Waals (vdWs) des complexes Znq+Imn (q = 0, 1, 2 ; n = 1–4). Ce travail à l’échelle microscopique, est utile pour comprendre la structure et la liaison se produisant dans les sites actifs contenant du zinc dans des systèmes biologiques (e.g. protéines). De plus, nos résultats peuvent être utilisés pour la détermination des champs de force précis pour les métalloprotéines ou les ZIFs.Les structures de type zéolithe–imidazole (Zeolitic–Imidazolate Frameworks ou ZIFs) sont composées de molécules organiques (e.g. molécules imidazoles) liées entre elles par des ions métalliques bivalents M+2 (e.g. M2+ = Zn+2/Co+2). Ces composés présentent une structure topologique bien stabilisée avec une large diversité de structure. Ils présentent ainsi une forte porosité qui est potentiellement utilisé dans la capture et le stockage du CO2 et dans son piégeage sélectif.Ces quantités au niveau microscopique sont nécessaires pour déduire les propriétés macroscopiques et thermochimiques de ces composés avec une bonne précision après incorporation dans des simulations dynamiques / The main goal of this work is to examine the capabilities of M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3 and M11 functionals with and without inclusion of D3 dispersion correction for the accurate description of medium sized organometallic compounds and therefore their use for the determination of study of the equilibrium structure, the stability, the spectroscopy and the chemical bonding (covalent, charge transfer and van der Waals) of Znq+Im (q = 0,1,2) complexes. This is done through close comparisons of the results obtained by the M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3, M11 functionals with and without inclusion of D3 dispersion correction and those from the standard ((R)MP2 and (R)CCSD(T)) and explicitly correlated ab initio methods (R)CCSD(T)-F12 and (R)MP2-F12. Therefore, we definitely establish that M05-2X+D3 and PBE0+D3 in connection with the 6-311++G(d,p) basis set are the methods of choice for the accurate description of medium sized organometallic compounds. This is illustrated through a systematic study of Zn+qIm of (q=0, 1, 2) complexes which play crucial roles in chemical, biological and industrial domains. Through these comparisons, we show that the results obtained at the M05-2X, M05-2X+D3, PBE0, PBE0+D3, PBE, PBE+D3, M11 levels are in good agreement with those explicitly correlated (R)MP2-F12 and (R)CCSD(T)-F12 methods. Through these comparisons, our study establishes the ability and reliability of M05-2X(+D3) functional for the accurate description of covalent and noncovalent interactions between Znq+ and Im since it leads to close agreement with the large ab initio techniques. PBE0 and M11 may be used also for that purposes. Then, we used high performance M05-2X and PBE0 functionals with and without inclusion of D3 dispersion correction in connection along with the 6-311++G(d,p) basis set to study the equilibrium structure, the stability, the spectroscopy and the chemical bonding (covalent, charge transfer and van der Waals) of Znq+Imn (q = 0, 1, 2, n = 1−4) complexes. This work, at the microscopic level, is useful for understanding the structural and bonding occurring in naturally zinc-binding sites and to figure out the behavior of much more complex biological systems. This should help for designing new zinc-binding proteins and more generally new metal sites in known proteins or ZIFs. The structural backbone of ZIFs is constructed from tetrahedral units formed by one bivalent metal ion (M2+ = Zn2+/Co2+) and four imidazolate anions. Such compounds present a well-established structural topology with a large structural diversity. They exhibit a high porosity which is potentially used for gas storage and separation techniques.Such quantities at the microscopic level are needed to deduce the macroscopic and thermochemical properties of these compounds with good accuracy after incorporation into dynamical simulations
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Možnosti zvýšení mrazuvzdornosti cihlářského střepu / Possibities to increase the frost resistance of brick bodyKeršner, Štěpán January 2014 (has links)
This thesis, which comprises of a theoretical and a practical part, deals with possible means of increasing ceramic body frost resistance. The current state of research in the field of ceramic body frost resistance is summarized in the theoretical part. The practical part is divided into two sections. In the first section, the influence of firing temperature (820 °C and 1020 °C) and duration (2, 4 and 6 hours) on frost resistance and several other parameters is assessed by means of experiment, using a specimen of brick body made of mixes currently used in roof tile production by TONDACH Šlapanice and TONDACH Dolní Jirčany factories. In the second section of the practical part, two modifications are introduced of the mixture currently used in roof tile production in the TONDACH Šlapanice factory – GE clay and zeolite supplements were added, the effects of which are verified by means of experiment using specimens fired in a kiln designated for ceramic masonry blocks and alternatively in a kiln used for firing TONDACH Šlapanice roof tiles.
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Odlučování olejového aerosolu z odpadního vzduchu ve výrobním provozu s obráběcími automaty / Removal of oil aerosol from the exhaust air in a production hall with automatic machine toolsŠtefánek, Stanislav January 2011 (has links)
This master thesis deals with the filtration of air contaminated with oil and the total efficiency and propose a new filtration system. The reason is insufficient capacity and functionality of the operating device is incorrect. It will propose the most appropriate solution to this in terms of economic and technical design is satisfactory.
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Teoretické studium mikroporézních materiálů pro využití v adsorpci a katalýze / Theoretical investigation of microporous materials for adsorption and catalysisPoložij, Miroslav January 2017 (has links)
Theoretical investigation of microporous materials for adsorption and catalysis Microporous materials are defined by a presence of pores with diameter smaller than 2 nm. They comprise a large variety of materials from amorphous materials to very well defined crystalline materials like zeolites or metal organic frameworks. Microporous materials are industrially very important group of materials used for adsorption, gas capture, molecular sieving, or heterogeneous catalysis. Zeolites are by far the most important group of microporous materials due to their use as catalysts for the petroleum cracking. One of the main limitations of the zeolite use in catalysis is their limited pore size. This obstacle can be solved by use of hierarchical zeolites with a secondary mesopore network which allows overcoming the diffusion problems. The aims of this study can be divided into two parts. In the first part, the structures of two-dimensional and hierarchical zeolites were investigated theoretically to identify the structure of new materials and to obtain reliable models to study the hierarchical zeolites. In the second part, the catalytic properties of several microporous materials were modelled to explain their experimental activity. The results of this thesis were used to identify the structure of a large...
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Mogućnost primene sintetičkog zeolita CR-100 (Crystal-Right™) za adsorpciju amonijaka iz podzemnih voda Banatskog akvifera / Possible application of synthetic zeolite CR-100(Crystal-Right™) in ammonia adsorption fromground water of Banat aquiferTomić Željko 29 December 2016 (has links)
<p>Uklanjanje amonijaka iz podzemnih voda u cilju dobijanja<br />pijaće vode predstavlja značajan problem, koji se do sada<br />rešavao primenom različitih postupaka. Poznato je da zeoliti<br />kao prirodni jonoizmenjivači i adsorbenti kvalitetno vezuju<br />amonijum jone u svoju alumosilikatnu matricu. Njihova<br />efektivnost, u različitim tehnološkim procesima, zavisi od<br />fizičko-hemijskih osobina, koje su usko povezane sa njihovim<br />geološkim nalazištima, kada se govori o prirodnim zeolitima.<br />Pored prirodnih zeolita u praksi se koriste i sintetički zeoliti<br />dobijeni raznim postupcima. Danas, je komercijalna primena<br />sintetičkih zeolita rasprostranjenija u odnosu na primenu<br />prirodnih, zbog čistoće kristalnih proizvoda i uniformne<br />veličina čestica. Crystal-Right™ (CR-100) je zeolit koji spada u<br />grupu najizdržljivijih proizvedenih minerala. Ovaj zeolit<br />podiže pH vrednost tretiranih voda, dok istvremeno smanjuje<br />tvrdoću i uklanjanja gvožđe i mangan. Ovo podešavanje pH i<br />uklanjanje nepoželjnih mineralnih materija postiže se izvrsnim<br />osobinama ovog zeolita u pogledu filtriranja, ali i ispiranja<br />nakon primene.<br />Maksimalna količina adsorbovanog amonijaka iznosi 2,31 mg<br />(98%) i 2 mg (87%), iz model rastvora i uzorka podzemne,<br />bunarske vode, redno. Prisustvo drugih komponenti u<br />bunarskoj vodi uzrokuje promene u količini adsorbovanog<br />amonijaka na zeolitu. Najbolje uklanjanje postignuto je za<br />jone kalijuma već sa najmanjim masama upotrebljenog<br />zeolita. Nasuprot tome, joni kalcijuma i magnezijuma se pri<br />nižim vrednostima doziranja zeolita slabije uklanjaju iz<br />bunarske vode, dok sa porastom doziranja raste i efikasnost<br />uklanjanja na svim posmatranim temperaturama.<br />Izbor adsorpcione izoterme je pokazao da najbolje rezultate<br />daje Freundlich-ova adsorpcione izoterme, a rezultati<br />aproksimacije ukazuju na fizičku adsorpciju na heterogenoj<br />površini. Negativne vrednosti entropije aktivacije upućuju na<br />zaključak da se radi o asocijativnoj adsorpciji amonijaka na<br />površinu zeolita, odnosno da postoji interakcija između<br />adsorbovanih molekula. Vrednosti entalpije aktivacije od<br />15,096 kJ/mol i 28,978 kJ/mol, za model rastvor i realan<br />sistem, redno, upućuju da se radi o endotermnom procesu,<br />što i potvrđuju podaci o ravnotežnim koncentracijama na<br />različitim temperaturama.<br />Tokom eksperimenata izvedenih sa poluindustrijskom<br />kolonom ispunjenom zeolitom Crystal Right™ (tip CR-100)<br />potvrđena je efikasnost u uklanjanju zeolita iz bunarske vode.<br />Između ispitanih modela za određivanje kinetike u kolonskom uređaju najboljim se pokazao model Yoon-Nelson-a.<br />Koeficijent linearne korelacije za model Yoon-Nelson-a iznosi -<br />0,975, dok je koeficijent determinacije imao vrednosti 0,950.<br />Iako je model razvijen jednokomponentne sisteme pokazao<br />se kao zadovoljovajući iako se radi o realnom sistemu<br />podzemne bunarske vode koja sadrži brojne rastvorene<br />supstance, katjone zemnoalkalnih i alkalnih metala, huminske<br />kiseline, anjone itd. Može se primetiti da je postignuto<br />zadovoljavaće slaganje eksperimentalnih podataka o<br />vremenu probaja sloja (50%) sa Yoon-Nelson-ovim modelom,<br />eksperimentalno određeno vreme proboja sloja iznosi oko 59<br />časova, dok je modelom dobijeno vreme 62 časa. Konstanta<br />brzine Yoon-Nelson-ovog modela iznosi 0,051 1/h.</p> / <p>Removing ammonia from groundwater to obtain drinking<br />water is an important issue, which is so far solved using<br />different methods. It is known that zeolites as natural ion<br />exchangers and adsorbents that bind ammonium ions in its<br />aluminosilicate matrix. Their effectiveness in various<br />technological processes depends on the physical and<br />chemical properties, which are closely related to their<br />geological sites, when it comes to natural zeolites. In addition<br />to the natural zeolites in practice synthetic zeolites are used.<br />Today, the commercial application of synthetic zeolites is<br />widespread in relation to the use of natural, due to the purity<br />of crystal products and uniform particle size. Crystal-Right ™<br />(CR-100) is a zeolite among the most durable minerals<br />produced. This zeolite raises the pH of the treated water, while<br />the same time it reduces the hardness and remove iron and<br />manganese. This pH adjustment and removal of undesirable<br />mineral substances is achieved by the excellent characteristics<br />of the zeolite in terms of filtering, and rinsing after application.<br />The maximum amount of adsorbed ammonia at 2.31 mg<br />(98%) and 2 mg (87%), from the model solution and the<br />sample of groundwater, well water, respectively. The presence<br />of other components in the well water causes changes in the<br />amount of ammonia adsorbed on zeolite. Selection of<br />adsorption isotherms showed that the best results are<br />achieved by Freundlich's adsorption isotherm, and the results<br />indicate physical adsorption on heterogeneous surfaces.<br />Negative values of entropy of activation lead to the<br />conclusion that it is associative adsorption of ammonia on the<br />surface of the zeolite, or that there is an interaction between<br />the adsorbed molecules. The values of enthalpy of activation<br />of 15,096 kJ / mol and 28,978 kJ / mol, for the model solution<br />and real system, respectively, indicating that it is an<br />endothermic process, which is confirmed by data on the<br />equilibrium concentrations at different temperatures.<br />Experiments conducted with the pilot plant column filled with<br />zeolite Crystal Right ™ (type CR-100) confirmed the<br />effectiveness in removing zeolite from well water. Among the<br />surveyed models to determine the kinetics of the column<br />device Yoon-Nelson's model has proven to be the best. The<br />linear correlation coefficient for the model Yoon-Nelson's is -<br />0.975, and the value of the coefficient of determination was 0.950. Although the model developed for one-component<br />systems it is proved to be satisfactory for ground water<br />ammonia adsorption. The agreement between experimental<br />data on the breakthrough point at 50% concentration (59<br />hours) with Yoon-Nelson's model, is good (62 hours). Constant<br />of Yoon-Nelson's model is 0.051 1 / h.</p>
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Estudos sobre a adsorção do corante reativo preto 5 de solução aquosa usando zeólita de cinzas de carvão / Studies on the adsorption of reactive black 5 dye of aqueous solution using zeolite of the coal ashesFerreira, Patricia Cunico 27 April 2011 (has links)
Nesta dissertação foi estudada a zeólita sintetizada a partir de cinzas leves de carvão como um potencial adsorvente para a remoção de corante reativo preto 5 (RP5). Ensaios cinéticos e de equilíbrio foram realizados visando obter-se as melhores condições para a adsorção deste corante, e verificou-se a influência dos seguintes parâmetros: efeito do tempo de contato, concentração inicial do corante, dose do adsorvente, pH da solução aquosa, adição dos sais NaCl e Na2SO4 e temperatura. O tempo de equilíbrio foi alcançado após 420 min. Os dados de adsorção foram ajustados melhor ao modelo cinético de pseudo-segunda-ordem. Para o sistema corante/adsorvente foi aplicado o modelo de isoterma de adsorção de Langmuir, apresentando capacidade de adsorção máxima de 0,685 mg g-1. Os dados experimentais mostraram uma alta porcentagem de remoção de 47,7 a 88,1% de RP5 sobre a zeólita. A alta porcentagem indicou que o material zeolítico apresenta potencial para ser usado como adsorvente na remoção de corantes azo reativo de indústrias têxteis. Os parâmetros termodinâmicos foram avaliados e demonstraram que o processo de adsorção do RP5 sobre a zeólita é espontâneo e exotérmico. Os experimentos adicionando os sais foram realizados para uma melhor simulação das condições reais do efluente. Os resultados mostraram que o equilíbrio de adsorção do RP5 sobre a zeólita na presença de sais foram alcançados em um tempo menor e que quanto maior a concentração dos sais na solução, maior a capacidade de adsorção. O resultado obtido na avaliação da toxicidade pelo microcrustáceo Daphnia similis, o tratamento de adsorção com zeólita se mostrou extremamente favorável5 reduzindo a carga tóxica e cor do efluente aquoso. / In this dissertation was studied the zeolite synthesized from coal fly ash as a potential adsorbent for the removal of reactive Black 5 dye (RP5). Equilibrium and kinetic experiments were conducted to obtain the best conditions for the adsorption of this dye, and observed the influence of the following parameters: effect of contact time, initial dye concentration, adsorbent dose, pH of the aqueous solution, addition of NaCl and Na2SO4 and temperature. The equilibrium time was reached after 420 min. The adsorption data were fitted better by a pseudo-second-order. For the dye / adsorbent system was applied to the model of Langmuir adsorption isotherm, with maximum adsorption capacity of 0.685 mg g-1. The experimental data showed a high percentage of removal from 47.7 to 88.1% of RP5 on the zeolite. The high percentage indicates that the zeolitic material has a potential to be used as adsorbent in the removal of azo dye reactive textile industries. The thermodynamic parameters were evaluated and showed that the adsorption process of RP5 on the zeolite is spontaneous and exothermic. The experiments were performed by adding salts to better simulate actual conditions in the effluent. The results showed that the adsorption equilibrium of reactive black 5 on the zeolite in the presence of salts were achieved in a shorter time and that the higher the concentration of salts in solution, the higher the adsorption capacity. The result obtained in the evaluation of toxicity by microcrustacean Daphnia similis treatment with zeolit adsorption was extremely favorable, reducing the toxic load of waste water and color.
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Adsorption av Sb på zeolit / Sb adsorption by zeoliteLundstedt, Evert January 2007 (has links)
Detta examensarbete är en förundersökning till Glafos undersökning angående rening av glasbrukens processvatten från antimon med zeolit. Förundersökningen gick ut på att via experiment ta reda på hur mycket antimon som adsorberas av behandlad (för optimering: dels med NaNO3 och dels med NaCl) och obehandlad zeolit (porstorlek 0.4 nm). pH mättes och ställdes eftersom det har betydelse för adsorptionen, åtminstone vid väldigt lågt pH. När lösningarna hade filtrerats mättes den kvarvarande antimonhalten med atomabsorptionsspektrofotometri. Mätningarna visade att i genomsnitt 53 % av Sb-halten i lösningarna hade adsorberats av zeoliten. Förundersökningen visade att det inte blir någon adsorption då pH är väldigt lågt (under 1). Den visade också att när pH är över 4 verkar det inte ha någon betydelse om zeoliten är behandlad eller inte. Zeoliten bör behandlas med NaCl först i en tank med omrörning, sedan blandas i processvattnet (vars pH justerats till pH 4) i en tank eller bassäng och därefter filtreras. Tidsfaktorn för hur lång tid det tar för zeoliten att nå jämvikt och temperaturens inverkan bör även undersökas. / The aim of this diploma work is to study the removal of antimony from glassworks process water using zeolites. The experimental part of the studies were carried out to find the quantity of antimony adsorbed by the zeolite. The studies included treated (for optimization: partly with NaNO3 and partly with NaCl) and untreated zeolite. The pore size is 0.4 nm. pH was measured and adjusted because it is important for the antimony adsorption. When the solutions were filtrated the content of antimony left was measured with atomic absorption spectrophotometry. The measurements showed an average uptake of antimony by the zeolite of 53 %.The preinvestigation indicates that with a very low pH (below 1) there is no antimony adsorption. It also indicates that with pH above 4 it does not matter if the zeolite are treated or not. In further investigations the zeolite should be treated with NaCl in a stirred tank, then be mixed in the process water (pH is set to 4) in a tank or basin and then be filtrated. The time to reach equilibrium and the influence of temperature should also be investigated.
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Adsorption av Sb på zeolit / Sb adsorption by zeoliteLundstedt, Evert January 2007 (has links)
<p>Detta examensarbete är en förundersökning till Glafos undersökning angående rening av glasbrukens processvatten från antimon med zeolit.</p><p>Förundersökningen gick ut på att via experiment ta reda på hur mycket antimon som adsorberas av behandlad (för optimering: dels med NaNO3 och dels med NaCl) och obehandlad zeolit (porstorlek 0.4 nm). pH mättes och ställdes eftersom det har betydelse för adsorptionen, åtminstone vid väldigt lågt pH. När lösningarna hade filtrerats mättes den kvarvarande antimonhalten med atomabsorptionsspektrofotometri. Mätningarna visade att i genomsnitt 53 % av Sb-halten i lösningarna hade adsorberats av zeoliten. Förundersökningen visade att det inte blir någon adsorption då pH är väldigt lågt (under 1). Den visade också att när pH är över 4 verkar det inte ha någon betydelse om zeoliten är behandlad eller inte.</p><p>Zeoliten bör behandlas med NaCl först i en tank med omrörning, sedan blandas i processvattnet (vars pH justerats till pH 4) i en tank eller bassäng och därefter filtreras.</p><p>Tidsfaktorn för hur lång tid det tar för zeoliten att nå jämvikt och temperaturens inverkan bör även undersökas.</p> / <p>The aim of this diploma work is to study the removal of antimony from glassworks process water using zeolites.</p><p>The experimental part of the studies were carried out to find the quantity of antimony adsorbed by the zeolite. The studies included treated (for optimization: partly with NaNO3 and partly with NaCl) and untreated zeolite. The pore size is 0.4 nm. pH was measured and adjusted because it is important for the antimony adsorption. When the solutions were filtrated the content of antimony left was measured with atomic absorption spectrophotometry. The measurements showed an average uptake of antimony by the zeolite of 53 %.The preinvestigation indicates that with a very low pH (below 1) there is no antimony adsorption. It also indicates that with pH above 4 it does not matter if the zeolite are treated or not.</p><p>In further investigations the zeolite should be treated with NaCl in a stirred tank, then be mixed in the process water (pH is set to 4) in a tank or basin and then be filtrated.</p><p>The time to reach equilibrium and the influence of temperature should also be investigated.</p>
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Estudos sobre a adsorção do corante reativo preto 5 de solução aquosa usando zeólita de cinzas de carvão / Studies on the adsorption of reactive black 5 dye of aqueous solution using zeolite of the coal ashesPatricia Cunico Ferreira 27 April 2011 (has links)
Nesta dissertação foi estudada a zeólita sintetizada a partir de cinzas leves de carvão como um potencial adsorvente para a remoção de corante reativo preto 5 (RP5). Ensaios cinéticos e de equilíbrio foram realizados visando obter-se as melhores condições para a adsorção deste corante, e verificou-se a influência dos seguintes parâmetros: efeito do tempo de contato, concentração inicial do corante, dose do adsorvente, pH da solução aquosa, adição dos sais NaCl e Na2SO4 e temperatura. O tempo de equilíbrio foi alcançado após 420 min. Os dados de adsorção foram ajustados melhor ao modelo cinético de pseudo-segunda-ordem. Para o sistema corante/adsorvente foi aplicado o modelo de isoterma de adsorção de Langmuir, apresentando capacidade de adsorção máxima de 0,685 mg g-1. Os dados experimentais mostraram uma alta porcentagem de remoção de 47,7 a 88,1% de RP5 sobre a zeólita. A alta porcentagem indicou que o material zeolítico apresenta potencial para ser usado como adsorvente na remoção de corantes azo reativo de indústrias têxteis. Os parâmetros termodinâmicos foram avaliados e demonstraram que o processo de adsorção do RP5 sobre a zeólita é espontâneo e exotérmico. Os experimentos adicionando os sais foram realizados para uma melhor simulação das condições reais do efluente. Os resultados mostraram que o equilíbrio de adsorção do RP5 sobre a zeólita na presença de sais foram alcançados em um tempo menor e que quanto maior a concentração dos sais na solução, maior a capacidade de adsorção. O resultado obtido na avaliação da toxicidade pelo microcrustáceo Daphnia similis, o tratamento de adsorção com zeólita se mostrou extremamente favorável5 reduzindo a carga tóxica e cor do efluente aquoso. / In this dissertation was studied the zeolite synthesized from coal fly ash as a potential adsorbent for the removal of reactive Black 5 dye (RP5). Equilibrium and kinetic experiments were conducted to obtain the best conditions for the adsorption of this dye, and observed the influence of the following parameters: effect of contact time, initial dye concentration, adsorbent dose, pH of the aqueous solution, addition of NaCl and Na2SO4 and temperature. The equilibrium time was reached after 420 min. The adsorption data were fitted better by a pseudo-second-order. For the dye / adsorbent system was applied to the model of Langmuir adsorption isotherm, with maximum adsorption capacity of 0.685 mg g-1. The experimental data showed a high percentage of removal from 47.7 to 88.1% of RP5 on the zeolite. The high percentage indicates that the zeolitic material has a potential to be used as adsorbent in the removal of azo dye reactive textile industries. The thermodynamic parameters were evaluated and showed that the adsorption process of RP5 on the zeolite is spontaneous and exothermic. The experiments were performed by adding salts to better simulate actual conditions in the effluent. The results showed that the adsorption equilibrium of reactive black 5 on the zeolite in the presence of salts were achieved in a shorter time and that the higher the concentration of salts in solution, the higher the adsorption capacity. The result obtained in the evaluation of toxicity by microcrustacean Daphnia similis treatment with zeolit adsorption was extremely favorable, reducing the toxic load of waste water and color.
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Fixace těžkých kovů v cementové matrici s příměsí přírodního zeolitu / Immobilization of heavy metals in the cement matrix with the admixture of natural zeoliteSemerádová, Nikol January 2017 (has links)
Heavy metals released to the natural ecosystem constitute significant risks not only for organisms, but also for water supplies in the nature. There are a number of analytical methods for the determination of heavy metals. Each of them is suitable for different element and its character. Since the results of the analysis are applied during the solidification and stabilization, it is necessary to ensure the highest correlation between hazardous waste and solidification medium for maximum inhibition of toxic ions. This work investigates the stabilization of heavy metals binders based on cement base with admixture of the natural zeolite and its possible use for the solidification of heavy metals in soluble form.
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