Sublimation experiments have been carried out to determine the effect of the mineral dust content of porous ices on the isotopic composition of the sublimate gas over medium (days to weeks) timescales. Whenever mineral dust of any kind was present, the D/H ratio of the sublimated gas was seen to decrease with time from the bulk ratio. Fractionations of up to 2.5 were observed for dust mixing ratios of 9 wt% and higher of JSC MARS-1 regolith simulant 1-10 mum crushed and sieved fraction. These favored the presence of the light isotope, H2O, in the gas phase. The more dust was added to the mixture, the more pronounced was this effect. Theoretical modeling of gas migration within the porous samples and adsorption on the excavated dust grains was undertaken to explain the results. Adsorption onto the dust grains is able to explain the low D/H ratios in the sublimate gas if adsorption favors retention of HDO over H2O. This leads to significant isotopic enrichment of HDO on the dust over time and depletion in the amount of HDO escaping the system as sublimate gas. This effect is significant for planetary bodies on which water moves mainly through the gas phase and a significant surface reservoir of dust may be found, such as on Comets and Mars. For each of these, inferences about the bulk water D/H ratio as inferred from gas phase measurements needs to be reassessed in light of the volatile cycling history of each body.PACS CODES:98.80.Ft Isotopes, abundances and evolution (astronomy)], 64.70.Hz Sublimation], 68.43.-h Adsorption at solid surfaces]

Batch equilibrium and dynamic column studies were undertaken to compare the metal-removal capabilities of two natural, low-cost materials (dried, crushed brown seaweed and shrimp shells) with a commercially available strong acid cation exchange resin (CER). All media maintained structural and hydraulic integrity over the duration of the column experiments. The batch tests showed that the low-cost materials demonstrated high adsorption capacities and affinities to Pb, Cu, Cd and Zn, but were slightly outperformed by the CER. Metal removal by each media was far superior to that reported for other types of low cost materials. Fixed beds of each media reduced concentrations of the target metals in a synthetic drainage water solution to levels below reference values measured at a case study site. This result suggests that any of the materials tested have the potential to completely remove impacts of a point source of metal contamination on the local water regime at the site. The CER column sustained the longest service time without large-scale breakthrough of any metal.

<p>Uklanjanje amonijaka iz podzemnih voda u cilju dobijanja<br />pijaće vode predstavlja značajan problem, koji se do sada<br />re&scaron;avao 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 tehnolo&scaron;kim procesima, zavisi od<br />fizičko-hemijskih osobina, koje su usko povezane sa njihovim<br />geolo&scaron;kim nalazi&scaron;tima, 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&trade; (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 pode&scaron;avanje 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 />povr&scaron;ini. Negativne vrednosti entropije aktivacije upućuju na<br />zaključak da se radi o asocijativnoj adsorpciji amonijaka na<br />povr&scaron;inu 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 />&scaron;to i potvrđuju podaci o ravnotežnim koncentracijama na<br />različitim temperaturama.<br />Tokom eksperimenata izvedenih sa poluindustrijskom<br />kolonom ispunjenom zeolitom Crystal Right&trade; (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 &trade;<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&#39;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 &trade; (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&#39;s model has proven to be the best. The<br />linear correlation coefficient for the model Yoon-Nelson&#39;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&#39;s model, is good (62 hours). Constant<br />of Yoon-Nelson&#39;s model is 0.051 1 / h.</p>

Made available in DSpace on 2014-12-17T15:03:25Z (GMT). No. of bitstreams: 1 HugoMBE_DISSERT.pdf: 3011454 bytes, checksum: f02eedee61c0464777dbee026e3a93cf (MD5) Previous issue date: 2010-12-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Eutrophication is a growing process present in the water sources located in the northeast of Brazil. Among the main consequences of these changes in trophic levels of a water source, stands out adding complexity to the treatment to achieve water standards. By these considerations, this study aimed to define, on a laboratory scale, products and operational conditions to be applied in the processing steps using raw water from Gargalheiras dam, RN, Brazil. The dam mentioned shows a high number of cyanobacteria, with a concentration of cells / ml higher than that established by Decree No. 518/04 MS. The same source was also considered by the state environmental agency in 2009 as hypereutrophic. The static tests developed in this research simulated direct filtration (laboratory filters) and pre-oxidation with chlorine and powdered activated carbon adsorption. The research included the evaluation of the coagulants aluminum hydrochloride (HCA) and alum (SA). The development of the research investigated the conditions for rapid mixing, the dosages of coagulants and pHs of coagulation by the drawing of diagrams. The interference of filtration rate and particle size of filtering means were evaluated as samples and the time of contact were tested with chlorine and activated carbon. By the results of the characterization of the raw water source it was possible to identify the presence of a high pH (7.34). The true color was significant (29 uH) in relation to the apparent color and turbidity (66 uH and 13.60 NTU), reflecting in the measurement of organic matter: MON (8.41 mg.L-1) and Abs254 (0.065 cm-1). The optimization of quick mix set time of 17", the speed gradient of 700 s-1 in the coagulation with HCA and the time of 20" with speed gradient of 800 s-1 for SA. The smaller particle sizes of sand filtering means helped the treatment and the variation in filtration rate did not affect significantly the efficiency of the process. The evaluation of the processing steps found adjustment in standard color and turbidity of the Decree n? 518/04 MS, taking in consideration the average values found in raw water. In the treatment using the HCA for direct filtration the palatable pattern based on the apparent color can be achieved with a dose of 25 mg L-1. With the addition of pre-oxidation step, the standard result was achieved with a reduced dose for 12 mgHCA.L-1. The turbidity standard for water was obtained by direct filtration when the dose exceeds 25 mg L-1 of HCA. With pre-oxidation step there is the possibility of reducing the dose to 20 mg L-1.The addition of CAP adsorption, promoted drinking water for both parameters, with even lower dosage, 13 mg L-1 of HCA. With coagulation using SA removal required for the parameter of apparent color it was achieved with pre-oxidation and 22 mgSA.L-1. Despite the satisfactory results of treatment with the alum, it was not possible to provide water with turbidity less than 1.00 NTU even with the use of all stages of treatment / A eutrofiza??o ? um processo cada vez mais presente nos mananciais situados no nordeste brasileiro. Entre as principais conseq??ncias destas altera??es nos n?veis tr?ficos da ?gua de um manancial destaca-se o acr?scimo de complexidade ao tratamento para potabiliza??o. Mediante a estas considera??es, este trabalho teve como objetivo definir, em escala de laborat?rio, produtos e condi??es operacionais a serem empregadas em etapas de tratamento utilizando ?gua bruta do a?ude Gargalheira, RN, Brasil. O a?ude em quest?o demonstra um n?mero de cianobact?rias elevado, apresentando uma concentra??o de c?lulas/ml superior aos n?veis estabelecidos pela Portaria MS n? 518/04. O mesmo, ainda foi considerado pelo ?rg?o ambiental do estado no ano de 2009 como hipereutr?fico. Os ensaios est?ticos desenvolvidos neste trabalho simularam filtra??o direta (filtros de laborat?rio), pr?oxida??o com cloro e adsor??o por carv?o ativado pulverizado. Foram avaliados os coagulantes hidr?xicloreto de alum?nio (HCA) e sulfato de alum?nio granulado (SA). O desenvolvimento da pesquisa buscou otimiza??o das condi??es de mistura r?pida, das dosagens de coagulantes e pHs de coagula??o com a constru??o de diagramas. As interfer?ncias da taxa de filtra??o e a granulometria do meio filtrante foram avaliadas e testaram-se dosagens e tempos de contato com cloro e com o carv?o ativado. Com os resultados da caracteriza??o da ?gua bruta foi poss?vel identificar no manancial a presen?a de um pH elevado (7,34). A cor verdadeira foi significativa (29 uH) em rela??o ? cor aparente e turbidez (66 uH e 13,60 uNT), refletindo-se nas medidas de mat?ria org?nica: MON (8,41 mg.L-1) e Abs254 (0,065 cm-1). A otimiza??o da mistura r?pida definiu o tempo de 17 , gradiente de velocidade de 700 s-1 na coagula??o com HCA e tempo de 20 , gradiente de velocidade de 800 s-1 para o SA. Granulometrias menores da areia do meio filtrante favoreceram o tratamento e a varia??o na taxa de filtra??o n?o interferiu de forma significativa na efici?ncia do processo. A avalia??o das etapas de tratamento verificou a adequa??o aos padr?es de cor aparente e turbidez da Portaria MS 518/2004 tomando como base os valores m?dios encontrados na ?gua bruta. No tratamento utilizando o HCA por filtra??o direta, a potabilidade para a cor aparente pode ser atingida com uma dosagem de 25 mg.L-1. Adicionando a etapa de pr?oxida??o o padr?o foi atingido com dosagem reduzida para 12 mgHCA.L-1. Para a turbidez a potabilidade foi obtida na filtra??o direta quando a dosagem supera 25 mg.L-1 de HCA. Com etapa de pr?oxida??o h? a possibilidade de redu??o da dosagem para 20 mg.L-1 de coagulante. O acr?scimo da adsor??o em CAP, promoveu a potabilidade para os dois par?metros, com dosagem ainda menor, 13 mg.L-1 de HCA. Coagulando com SA a remo??o necess?ria para o par?metro de cor aparente foi atingida com pr?oxida??o e dosagem de 22 mgSA.L-1. Apesar de apresentar bons resultados o tratamento com o sulfato de alum?nio n?o foi capaz de fornecer ?gua com turbidez menor que 1,00 uNT mesmo com a utiliza??o de todas as etapas de tratamento

In the first part of this thesis the methodic of lab trial was studied, which will be useful for studying adsorption of natural organic matter by activated carbon. As an optimal method of testing adsorption characters jar testing was chosen. Again as an indicator of organic contamination, it was decided to use permanganate chemical oxygen demand (in Czech CHSKMn) will be used. In the second part of this thesis the adsorption characters of eight types of granular activated carbon were studied. Those granular activated carbon came from two world produces, from company NORIT five type of granular activated carbon were tested: NORIT GAC 1020, NORIT PK 1-3, NORIT GAC 1240, NORIT ROW 0.8 SUPRA a TOD NORIT ROX 0.8 and from company Chemviron Carbon three types of granular activated carbon were tested: F100 FE11120A, F400 FE11210A a TL830 FE2028B. Batch kinetic tests of natural organic matter adsorption were conducted with all types of granular activated carbon at first. For description of sorption not only the batch kinetic tests and duration needed for setting equilibrium were observed, but also the process decreasing of concentration of natural organic matters to the value of equilibrium concentration known as adsorption equilibrium was followed.

In my diploma thesis I focused on the issue of metals, their occurrence in drinking water sources in the Czech Republic and the possibility of their removal by water supply processes. Heavy metals degrade the quality of water resources, so more complex water treatment technologies are needed. The first part describes the metals, their properties, their significance and occurrence in water, then the possibility of removing metals using water supply processes. In the practical part of the diploma thesis I performed a laboratory experiment to remove iron, manganese and nickel by adsorption on selected filter materials, which are Filtrasorb F100, Filtrasorb F 400, Bayoxide E33 and GEH. The experiment was used to compare the effectiveness of selected sorption materials.