Submitted by MILENA RODRIGUES BONIOLO null (milenaboniolo@yahoo.com.br) on 2016-04-14T01:20:37Z No. of bitstreams: 2 REPOSITORIO_Boniolo.pdf: 2914547 bytes, checksum: 81f538abdf07d7db7b952a1c412aeb9a (MD5) REPOSITORIO_Boniolo.pdf: 2914547 bytes, checksum: 81f538abdf07d7db7b952a1c412aeb9a (MD5) / Rejected by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: - A data de defesa informada durante a submissão está diferente da data que consta na capa e folha de rosto. - Foram submetidos 2 arquivos PDF’s, apenas 1 arquivo deve ser submetido. Por favor, corrija estas informações e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2016-04-14T19:49:13Z (GMT) / Submitted by MILENA RODRIGUES BONIOLO null (milenaboniolo@yahoo.com.br) on 2016-04-15T00:59:57Z No. of bitstreams: 1 REPOSITORIO_Boniolo.pdf: 2914406 bytes, checksum: 1b92b8a055ad1cfc71027ce20781089a (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-15T12:55:02Z (GMT) No. of bitstreams: 1 boniolo_mr_dr_rcla.pdf: 2914406 bytes, checksum: 1b92b8a055ad1cfc71027ce20781089a (MD5) / Made available in DSpace on 2016-04-15T12:55:02Z (GMT). No. of bitstreams: 1 boniolo_mr_dr_rcla.pdf: 2914406 bytes, checksum: 1b92b8a055ad1cfc71027ce20781089a (MD5) Previous issue date: 2016-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A escassez qualitativa e quantitativa de água associada aos impactos ambientais impostos por águas residuárias tem agravado o cenário da situação ambiental brasileira. Um setor que merece destaque é o de mineração de urânio visto que o Brasil é a sexta maior reserva mundial deste elemento e existe grande quantidade de rejeitos acumulados contendo íons metálicos, semimetálicos e radiotóxicos. A biossorção tem se mostrado eficiente no tratamento das águas residuárias com íons que mesmo em baixas concentrações são tóxicos. O objetivo deste trabalho foi avaliar a redução da concentração de urânio em soluções e em amostras de águas de drenagem ácida de minas da mina Osamu Utsumi das Indústrias Nucleares do Brasil por meio da biossorção. As biomassas escolhidas para uso como biosorvente foram cascas de banana, sementes de moringa e borra de café. Ensaios de decomposição térmica, porosimetria de adsorção de nitrogênio e microscopia eletrônica de varredura foram efetuados de modo a caracterizar fisicamente os biosorventes. As variáveis analisadas para os ensaios em batelada como tamanho e massa do biosorvente, temperatura do ensaio, tempo de contato, pH e concentração inicial da solução de urânio foram definidas com o planejamento fatorial de experimentos. A partir dos ensaios em batelada realizados, pôde-se observar que as biomassas com maior área superficial e menor volume de poros resultaram em maiores valores de eficiência de remoção, sendo a ordem crescente destes parâmetros: cascas de banana < borra de café < sementes de moringa. Dentre os biosorventes estudados as sementes de moringa apresentaram os maiores valores de eficiência de remoção, seguida pela borra de café e cascas de banana. Em soluções de 100 mg L-1 as eficiências de remoção das sementes de moringa e cascas de banana foram iguais a 0,7429 e 0,2483, respectivamente; em valores de concentração de 25 mg L-1 as borras de café apresentaram eficiência de remoção igual a 0,9358. Em amostras de efluente com concentrações de urânio na ordem de 5 mg L-1 , as sementes de moringa apresentaram-se como o biosorvente com melhor eficiência de remoção (~0,8) quando comparadas as cascas de banana (~0,5) e borra de café (~0,7). / The qualitative and quantitative water scarcity associated with environmental impacts posed by wastewater has worsened the brazilian environmental scenario. Uranium mining is a prominent sector in Brazil context, since this country owns the sixth biggest uranium reserve in the world and there is large amount of accumulated tailings containing metallic, semi-metallic and radiotoxic ions. In general, biosorption has shown significant efficiency on effluent treatment, removing ions which even in low concentrations present toxicity. This work aimed to reduce the concentration of uranium by using biosorption in both cases, lab scale solutions and acid mining drainage effluent samples from Osamu Utsumi mine, wich belongs to Usinas Nucleares do Brasil. The selected biomasses used as biosorvent were banana peels, moringa’s seeds and coffee waste. Thermal decomposition, nitrogen adsorption porosimetry and scanning electron microscopy were performed for physical characterization. The studied variables for the batch tests as size and mass of biosorvent, temperature of tests, contact time, pH and initial concentration of solutions of uranium were defined by using design of experiments. From the tests carried out it was observed that the biomasses with a higher surface area and smaller pore volume resulted in higher removal efficiency values, with an ascending order of these parameters: banana peels <coffee grounds <seed moringa. Among the studied biosorvents, moringa seeds showed the highest values of removal efficiency followed by the coffee waste and banana peel. Based on tests using uranium solutions of 100 mg L-1, the removal efficiency of moringa seeds and banana peel were 0,7429 and 0,2483, respectively; assuming concentration of 25 mg L-1 the coffee wastes has shown efficiency of removal of 0,9358. In effluent samples with uranium concentrations in the order of 5 mg L-1, the moringa seeds were presented as the biosorbent with better removal efficiency (~ 0.8) when compared to banana peels (~ 0.5) and coffee waste (~ 0.7).

Dissertation submitted in fulfilment of requirements for the degree Master of Technology: Chemical Engineering In the FACULTY OF ENGINEERING 2014 / In South Africa only 5% of the coal fly ash produced annually by power stations finds use. Due to the high quantities of Si and Al in the coal fly ash researchers have explored the opportunity to use the fly ash as a feedstock in zeolite synthesis. Two principal methods have been successfully employed on a micro scale namely the 2-step method and fusion assisted method. However, in order to scale-up these processes some fundamental process design changes are required. Fly ash contains various elements including highly toxic elements such as As, Pb and Hg. The fate of these elements during the synthesis processes is not known. Both these processes generate large quantities of liquid supernatant waste. Disposal of these wastes would be expensive and environmentally harmful, thus making these processes industrially unfeasible. The well known fusion assisted process, contains an energy intensive fusion step operating at 550 C. Construction and operation of a furnace to implement fusion would be too expensive on an industrial scale. The 2-step method has a time consuming pre-hydrothermal treatment step (aging step). In order to improve the feasibility of the 2-step process the processing time of the aging step needs to be reduced. In order to breach the scale gap between micro and pilot plant scale a principal reactor design has been suggested. However, to date, no consideration has been given to the safety and operational reliability of this design. A HAZOP study is required to prevent costly incidents from occurring during the operation of this reactor. The aim of this study formed part of the overall initiative to scale-up the synthesis of zeolites to pilot and ultimately do at industrial scale. The aim of this study specifically was to perform some principal process design activities in order to prepare these processes for scale-up. The objectives were to perform material balances on the two principals synthesis approaches in order to determine the distributional fate of elements. Secondly, to make critical process design changes and develop protocols whereby the supernatant waste resulting from these processes can be minimised. Thirdly, to replace the fusion step (used in the fusion assisted process) and the aging step (used in the 2-step process) with a short high intensity sonochemical treatment step. Lastly, to perform a HAZOP study on the principal bench scale reactor design, and make design changes based on the outcome of the study. Material balances illustrated that most of the elements originating from the coal fly ash (Fe, Mn, Mg, Ca, Ti, Ba, Ce, Co, Cu, Nb, Ni, Pb, Rb, Sr, Y and Zn) do not leach out into solution during either of the two synthesis approaches. This was due to the CaO content in the ash retarding the mobility of these elements. This meant that during the 2-step process these elements reported to the overall zeolite product but did not form part of the zeolite crystal structure. On the other hand, during the fusion assisted process these elements reported to the solid residue waste. The yield efficiency of the fusion assisted process was found to be poor with only 19.6% of the Si and 21.6% Al reporting to the zeolite A product. The 2-step process on the other hand incorporated 72.2% of the Si and 81.5% Al into the zeolite product. However, the 2-step process produced a mixed phase zeolite product while the fusion assisted process produced a pure phase zeolite A product. Therefore there is a trade-off between yield efficiency and product purity. It was found that the liquid supernatant waste produced during both the synthesis processes contained toxic elements such as As, Pb, Hg, Al and Nb. This highlighted the importance to minimise the liquid supernatant waste generated. The waste minimisation studies illustrated that the liquid supernatant waste can be recycled while still producing highly crystalline zeolite products, in both the synthesis approaches. During the 2-step process the supernatant waste was recycled as a source of NaOH. By recycling the waste it was found that 40% of the supernatant could be recycled. However, by making a minor process design change a protocol was developed whereby 100% of the supernatant waste could be recycled. Also, by recycling the liquid waste, zeolite analcime became the dominant phase due to the accumulation of Si in the waste. In the fusion assisted process, protocols were developed whereby the liquid supernatant waste was recycled as a source of water. It was found that 100% of the supernatant could be recycled without compromising the relative crystallinity and purity of the zeolite A product. Both the fusion step (used in the fusion assisted approach) and the 48 hr aging step (used in the 2-step process) could be replaced with 10 min of sonochemical treatment. It was found in both cases that the introduction of ultrasound, during the pre-hydrothermal stage, increased the rate of crystal formation during the hydrothermal treatment step. It was also found that by replacing the high temperature fusion step, in the fusion assisted process, the required hydrothermal treatment temperature could be reduced to 90 C. By introducing sonochemical treatment in these two synthesis approaches their synthesis time and energy demands could be reduced successfully. A HAZOP study on the principal bench scale reactor design enabled design changes to be made preventing future loss during operation. A final optimised reactor design was proposed based on the outcome of the HAZOP study. This study effectively prepared both zeolite synthesis approaches for up-scale operation. Scale-up of this process will reduce disposal of coal fly ash offering relief to the financial and environmental strain caused to the country.

Gruvavfall, i form av gråberg, från Kiirunavaara-gruvan i Kiruna, norra Sverige undersöktes för att se om surt lakvatten kan bildas från gråberget och om detta kan ha en påverkan på hur mycket kväve som kan lakas ut från gråberget. För detta ändamål gjordes dels en mineralogisk undersökning av gråberget, med siktning, röntgendiffraktion (XRD) och grundämnesanalys och dels laborativa skakförsök. Från skakförsöken, där olika kornstorlekar (8-16 mm, 2-4 mm och mindre än 1 mm) blandades med avjoniserat vatten med L/S-kvoten 10, kunde förändringar i pH, alkalinitet och lösta joner undersökas över en 10-veckors period.                       De främsta mineralen i gråberget i Kiirunavaara visades vara plagioklas, kvarts och biotit. I gråberget finns även 18 g pyrit/kg gråberg. Skakförsöken indikerar att lakvattnet från gråberget i Kiirunavaara är alkaliskt med ett pH över 9. Vittring av sulfidmineral sker, men neutraliseras av buffrande mineral som kalcit och ingen potential till produktion av surt lakvatten finns. Kväveutlakningen sker främst under de första dygnen, men mer än hälften av de kväveföreningar som antas finnas i gråberget lakas inte ut. Både nitrat och ammonium visade signifikanta korrelationer med pH, där högre pH-värden tydde på högre nitratkoncentrationer och lägre pH-värden på högre ammoniumkoncentrationer. Detta indikerar att även om inget samband kunde ses mellan produktion av surt lakvatten och kväveutlakning, så är mängden av olika kväveföreningar som lakas ut beroende av lakvattnets pH-värde. / Mining waste rock from the Kiirunavaara-mine in northern Sweden was studied to determine if there is a potential for production of acid mine drainage (AMD), if there is a leaching of nitrogen compounds from the waste rock and if a correlation between the two processes can be seen. A mineralogical characterization of the waste rock was done through dry sieving, X-Ray Diffraction (XRD) and elemental analysis. Through shake flask experiments, where waste rock of three different grain sizes (8-16 mm, 2-4 mm and less than 1 mm) were mixed with deionized water (L:S-ratio of 10), the change in pH, alkalinity and dissolved ions during a 10-week period was determined.                       The waste rock in Kiirunavaara was found to consist mainly of plagioclase, quartz and biotite, but the waste rock also contains 18 g pyrite per kg waste rock. The shake flask experiments indicate that the mine drainage from the waste rock in Kiirunavaara is alkaline, with a pH above 9. Weathering of sulphide minerals occur, but are neutralised by buffering minerals such as calcite and thus no potential for AMD-production exists. The leaking of nitrogen compounds occurs mainly during the first few days. Both ammonium and nitrate showed significant correlations with pH, where lower pH-values typically exhibited higher ammonium concentrations, while higher pH-values correlated with higher nitrate concentrations.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.