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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

Adsorcao de corante reativo remazol vermelho RB de solucao aquosa usando zeolita de cinzas de carvao e avaliacao da toxicidade aguda com Daphnia similis / Adsorption of reactive remazol red RB dye of aqueous solution using zeolite of the coal ash and evaluation of acute toxicity with Daphnia similis

MAGDALENA, CARINA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:28:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:22Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
32

Desenvolvimento de tijolos com incorporação de cinzas de carvão e lodo proveniente de estação de tratamento de água / Development of bricks with incorporation of coal ash and sludge from water treatment plant

SILVA, MAURO V. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:41Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
33

Preparados homeopáticos e cinzas dinamizadas no manejo de tiririca-roxa (Cyperus rotundus L.) / Homeopathic and dynamic preparations in the management of purple nutsedge (Cyperus rotundus L.)

Arendartchuk, Cleiton 24 February 2017 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-01T15:11:23Z No. of bitstreams: 1 PGPV17MA226.pdf: 296583 bytes, checksum: 632e5c3fdc904ca285838ae8f37c238d (MD5) / Made available in DSpace on 2018-03-01T15:11:23Z (GMT). No. of bitstreams: 1 PGPV17MA226.pdf: 296583 bytes, checksum: 632e5c3fdc904ca285838ae8f37c238d (MD5) Previous issue date: 2017-02-24 / The Cyperus rotundus L. is a perennial and spontaneous herbaceous plant that infers an area of human interest and interferes detrimentally in agricultural activities. Seeking alternatives for a reduction of competition between cultivated and spontaneous plants that can be applied mainly by agroecological farmers, this work had the objective of evaluating the efficiency of C. rotundus biodynamic ashes and High dynamized dilution on C. rotundus control. The studies were conducted from September 2015 to January 2016, in a greenhouse at the Curitibanos Campus of University Federal of the Santa Catarina. The sample was tray 50.5 x 30 x 8 cm, planted ten tubers, repeated four times. In double blind where there are homeopathies. The experiments with ashes of purple nutsedge differed dates 09/12/15 and 09/26/15: T1-control; T2 -20% acetic acid; T3-ash at 30, 31 and 32 days after plan (DAP); T4-ash at 30, 31 and 32 + 60, 61 and 62 (DAP); T5-ash at 30, 31 and 32 + 60, 61 and 62 + 90, 91 and 92 (DAP); T6 - ashes at 30, 31 and 32 + 60, 61 and 62 + 90, 91 and 92 + 120, 121 and 122 (DAP). The experiment with homeopathies: T1- Magnesia carbonica CH10 (centesimal hahnemanniana), T2- Saccharum officinale CH10, T3-Natrum arsenicum CH10, T4-Limestone CH10, T5-control; 20% T6-acid at 35 and 70 (DAP). The weight of the tubers 4.75 ± 0.15 gr per plot; Seeded in sterilized soil, in a greenhouse with irrigation. The double-blind homeopathic applied at 30, 60, 90 and 120 (DAP). Comments extended around 4.5 months. The results were compared by the student's test and then variance when significant. Treatment with 20% acetic acid seeded (09/26/15) - ash tends to better controls with a mean of 47% up to a maximum of 76% mortality. The acid can collaborate without control, with later researches. / A tiririca roxa (Cyperus rotundus L.) planta herbácea perene prejudicial à agropecuária. Avaliaram-se cinzas dinamizadas de tiririca roxa e preparados homeopáticos no seu controle. A amostra foi bandeja 50,5 X 30 X 8 cm, plantado dez tubérculos, repetida quatro vezes. Em duplo cego onde houver homeopatias. Os experimentos com cinzas de tiririca roxa diferiram datas 12/09/15 e 26/09/15: T1-testemunha; T2 –ácido acético a 20%; T3-cinzas aos 30, 31 e 32 dias após plantio (DAP); T4-cinzas aos 30, 31 e 32 + 60, 61 e 62 (DAP); T5-cinzas aos 30, 31 e 32 + 60, 61 e 62 + 90, 91 e 92 (DAP); T6 – cinzas aos 30, 31 e 32 + 60, 61 e 62 + 90, 91 e 92 + 120, 121 e 122 (DAP). O experimento com homeopatias: T1- Magnesia carbonica na CH10 (centesimal hahnemanniana), T2- Saccharum officinale CH10, T3- Natrum arsenicosum CH10, T4- Calcário dolomítico CH10, T5- testemunha (sem intervenção) e T6 - herbicida alternativo (ácido acético a 20%). O tratamento T6 foi utilizado como testemunha aos 35 e 70 dias após a emergência à aplicação do ácido. Os homeopáticos aplicaram-se aos 30, 60, 90 e 120 (DAP). Em todos os experimentos foi avaliado: a) germinação semanal iniciada um mês após o plantio (MAP), b) altura de plantas, c) diâmetro de cada colmo inicial e dos perfilhos nascidos depois de dois (MAP), d) mortalidade semanal decorrido um (MAP); e) pesagem de fração de 30% da matéria fresca de folhas para o teste de matéria seca; f) pesagem da matéria fresca total aérea; g) pesagem da matéria fresca total das raízes e tubérculos; h) pesagem de fração de 30% da matéria fresca de folhas para o teste de matéria seca de folhas; i) pesagem de fração de 30% da matéria fresca de raízes para o teste de matéria seca de raízes e tubérculos; e j) contagem dos perfilhos totais por tratamento após 30 (DAP). Os dados submetidos à análise de variância e comparados pelo teste t de Student a 5% quando significativo. As cinzas dinamizadas e os preparados homeopáticos avaliados apresentaram efeito discreto a nulo sobre as seguintes variáveis: a, b, c, d, e, f. O ácido acético a 20% promoveu morte de até 76% de plantas de C. rotundus e as médias de mortalidade durante a avaliação foram de 47%, 14,8%, 9,6% para os tratamentos com ácido 17 acético a 20% os experimentos: cinzas 26 09; cinzas 12 09 e homeopatias 12 09 respectivamente. Serão necessários estudos para ajustes de cinzas dinamizados e preparados homeopáticos no controle da tiririca. O preparado a base de ácido acético a 20% pode ser usado com outras técnicas agroecológicas, por apresentar viabilidade
34

Síntese de zeólitas a partir de cinzas de carvão e aplicação como adsorventes

Zen, Barbara Potrich January 2016 (has links)
Cinzas oriundas da combustão de carvão são resíduos produzidos no processo de geração de energia em termoelétricas. Esses resíduos industriais podem ser aproveitados como matéria prima para síntese de zeólitas, as quais são materiais aluminossilicatos porosos com importantes aplicações, como adsorventes no tratamento de efluentes líquidos. Nesse contexto, o objetivo deste trabalho foi sintetizar zeólitas a partir de três diferentes cinzas de carvão e utilizá-las na remoção de corante violeta cristal em soluções aquosas via processo de adsorção. Para isso, foram sintetizadas zeólitas denominadas ZP, ZF e ZFD a partir de três diferentes cinzas de carvão, sendo elas, respectivamente: cinzas de carvão de combustão em leito pulverizado, de combustão em planta piloto de leito fluidizado e de combustão em planta piloto de leito fluidizado utilizando processo de dessulfuração interna. A síntese foi feita pelo método hidrotérmico, utilizando NaOH 3 mol L-1 como agente mineralizante, relação líquido/sólido (L/S) igual a 6 e tempo de reação de 24 h a 100 °C. Os materiais obtidos foram submetidos à caracterização física, química e morfológica, nas quais foi observada a formação de três diferentes fases zeolíticas (zeólitas P, X e sodalita) nas amostras ZF e ZFD, e uma única fase (zeólita P) na amostra ZP. Os valores de área superficial BET encontrados foram de 17, 35 e 40 m2 g-1 para as zeólitas ZP, ZFD e ZF, respectivamente, com tamanho de poros na faixa de 3 a 4 nm para os três materiais. Os valores de capacidade de troca catiônica (CTC) ficaram entre 2,07 e 2,85 meq NH4 + g-1. Posteriormente foram realizados ensaios de adsorção do corante em que foi avaliada a influência do pH, tempo de contato e concentração de sólido adsorvente. Ainda, foram construídas isotermas de adsorção para esses sistemas e os modelos de isotermas de Langmuir, Freundlich e BET modificado foram ajustados aos dados experimentais. Os resultados mostraram que a maior eficiência foi obtida pela zeólita ZF, alcançando máxima remoção de corante de 85 % nos estudos do efeito do tempo de contato, e as melhores condições experimentais obtidas foram de 60 min e 15 g L-1 de concentração de sólido adsorvente. O modelo de isotermas que melhor se ajustou aos dados experimentais foi BET modificado, com R2 = 0,9894. A síntese de zeólita a partir de cinzas de carvão mostrou potencial na produção de um adsorvente alternativo para remoção do corante violeta cristal de águas contaminadas, contribuindo também para a diminuição do impacto ambiental das atividades de combustão de carvão. / Ashes from coal combustion are waste produced in the process of power generation in thermoelectric. These industrial wastes can be used as raw material for zeolite synthesis, which are porous aluminosilicate with important applications, such as adsorbents in the treatment of liquid effluents. The objective of this study was to synthesize zeolites from three different coal ash and apply it in crystal violet dye adsorption processes in aqueous solution. Thereunto, zeolites called ZP, ZF e ZFD were synthesized from the three different coal ashes, as so, respectively: coal ashes from powdered bed combustion, from combustion in a fluidized bed pilot plant and from combustion in a fluidized bed pilot plant with internal desulphurization. The synthesis was carried by hydrothermal method, using NaOH 3 mol L-1 as the mineralizing agent, the liquid/solid ratio (L/S) equal to 6 and 24 hours reaction time at 100 ° C. The materials were subjected to physical, chemical and morphological characterization and it was observed the formation of three different zeolite phases (zeolites P, X and sodalite) in the sample ZF and ZFD, and a single phase (zeolite P) in ZP sample. The BET surface area values were 17, 35 and 40 m2 g-1 to ZP, ZFD and ZF zeolites, respectively, with pore size in the range of 3 to 4 nm for all three materials. The values of cation exchange capacity (CEC) were between 2.07 and 2.85 meq NH4 + g-1. Subsequently, adsorption tests were carried out in which it was evaluated the influence of pH, contact time and adsorbent solid concentration. Still, adsorption isotherms were built for these systems and isotherm models of Langmuir, Freundlich and modified BET were fitted to experimental data. The results showed that the highest efficiency was obtained by zeolite ZF, achieving maximum dye removal of 85 % in the studies of contact time effects, and the best experimental conditions were 60 min and adsorbent solid concentration of 15 g L-1. The BET isotherm model was found to be the best fit to experimental data, with R2 = 0.9894. The zeolite synthesis from coal ash has shown potential in the production of an alternative adsorbent to remove the crystal violet dye from contaminated water, also contributing to reducing the environmental impact of coal combustion activities.
35

Adsorcao de corante reativo remazol vermelho RB de solucao aquosa usando zeolita de cinzas de carvao e avaliacao da toxicidade aguda com Daphnia similis / Adsorption of reactive remazol red RB dye of aqueous solution using zeolite of the coal ash and evaluation of acute toxicity with Daphnia similis

MAGDALENA, CARINA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:28:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:22Z (GMT). No. of bitstreams: 0 / No presente estudo, a capacidade da zeólita sintetizada a partir de cinzas de carvão na remoção do corante remazol vermelho RB de solução aquosa foi investigada por meio de processo descontínuo. O equilíbrio foi alcançado após 360 min de tempo de contato. A velocidade de adsorção seguiu o modelo cinético de pseudo-segunda-ordem. Os dados de equilíbrio obtidos se ajustaram à isoterma de adsorção de Langmuir apresentando capacidade de adsorção máxima de 1,20 mg g-1. A eficiência de adsorção estava entre 75 a 91 % no tempo de equilíbrio. Visando obter as melhores condições de remoção do corante, verificou-se a influência dos seguintes parâmetros: concentração inicial do corante, pH da solução aquosa, dose do adsorvente e temperatura. Os parâmetros termodinâmicos foram avaliados indicando que o processo de adsorção do remazol vermelho sobre a zeólita é de natureza espontânea. Experimentos adicionando-se NaCl e Na2SO4 foram realizados com o objetivo de simular as reais condições dos efluentes de banhos de tingimento e avaliar a influência destes compostos quimicos no fenômeno de adsorção. Os dados de equilíbrio de adsorção do remazol vermelho sobre a zeólita foram alcançados em um tempo menor na presença de concentrações crescentes dos sais em solução e houve um aumento na capacidade de adsorção. A eficiência do estudo como tratamento foi avaliada quanto à toxicidade aguda utilizando o microcrustáceo Daphnia similis. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
36

Desenvolvimento de tijolos com incorporação de cinzas de carvão e lodo proveniente de estação de tratamento de água / Development of bricks with incorporation of coal ash and sludge from water treatment plant

SILVA, MAURO V. da 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:41Z (GMT). No. of bitstreams: 0 / Os lodos provenientes de estação de tratamento de água brasileira são, frequentemente, dispostos e lançados diretamente nos corpos d\'água, causando um impacto negativo no meio ambiente. Também, cinzas de carvão são produzidas pela queima de carvão em usinas termelétricas e é o resíduo sólido industrial mais gerado no sul do Brasil: cerca de 4 milhões ton/ano. A disposição eficiente das cinzas de carvão é um problema devido ao seu volume maciço e aos riscos nocivos para o ambiente. O objetivo deste trabalho foi estudar a viabilidade da incorporação desses dois resíduos industriais em uma massa utilizada na fabricação de tijolos ecológicos. As amostras de cinzas leve do filtro ciclone da usina termelétrica localizada no Município de Figueira, Estado do Paraná, Brasil e o lodo de estação de tratamento de água localizada no município de Terra Preta, Estado de São Paulo, Brasil, foram utilizados no estudo. Tijolos de cinzas leve-lodo e cinzas leve-lodo-solo-cimento foram moldados e testados de acordo com padrões brasileiros. Os materiais foram caracterizados por análises físico-químicas, difração de raios X, análise térmica, análise morfológica, espectroscopia no infravermelho com transformada de Fourier e análise granulométrica. Os resultados indicaram que o lodo de estação de tratamento de água e as cinzas de carvão podem ser usados na manufatura de tijolos prensados solo-cimento de acordo com a Norma Brasileira NBR 10836/94. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
37

Devenir de l’arsenic dans une papeterie : étude de cas / Arsenic fate in a pulp and paper mill : a case study

Michon, Clémence 04 February 2011 (has links)
Les objectifs de ce travail étaient de déterminer les sources et le devenir de l’arsenic dans une papeterie vosgienne, et en particulier dans sa station d’épuration, afin de comprendre les variations de la concentration en arsenic dans l’effluent traité par la station et rejeté dans la Moselle.Les papiers récupérés utilisés pour la production de pâte désencrée représentent la source majoritaire d’arsenic pour la papeterie, puis les combustibles incinérés dans le secteur énergie. Les sorties majoritaires sont les cendres produites par le secteur énergie, puis le papier produit. Le devenir de l’arsenic dans le procédé de désencrage est complexe et implique des phénomènes de transfert entre le circuit de la pâte à papier et le circuit des eaux. L’arsenic présent dans les eaux blanches semble provenir des matières en suspension. Des dysfonctionnements dans le secteur énergie ont causé le départ de cendres produites dans la chaudière à la station d’épuration via les eaux de lavage du laveur de fumées. Ces cendres peuvent avoir une concentration en arsenic très importante et pourraient être l’une des causes des dépassements de la limite de rejet en arsenic. La station d’épuration peut éliminer de la phase aqueuse jusqu’à 50 % de l’arsenic entrant à la station après neutralisation/décantation et traitement par boues activées. Un traitement tertiaire par coagulation (par des sels d’aluminium) / floculation / flottation permet de diminuer encore la concentration en arsenic dans le rejet en fonction des conditions de fonctionnement / This study was about the sources and the fate of arsenic in a pulp and paper mill located in the Vosges, and particularly in the wastewater treatment plant, in order to understand the variations of the arsenic concentration in the treated effluent discharged in the Moselle River.The recovered papers used for the production of deinked pulp are the main source of arsenic for the pulp and paper mill, followed by the solid fuels incinerated in the boiler of the energy area of the mill. The main outputs are the ashes produced by the boiler, then the produced paper. The fate of the arsenic in the deinking process is complex and involves transfer phenomena between the pulp and the white water of the process. Arsenic present in white water could come from the suspended solids. Malfunctions in the energy area have caused the departure of ashes to the wastewater treatment plant via the washing water of the flue gas washer. Those ashes may contain a high arsenic concentration and could be one of the sources of the large variations of the arsenic concentration in the effluent of the wastewater treatment plant. This wastewater treatment plant is able to eliminate up to 50% of arsenic of the effluent thanks to neutralization/decantation and biotreatment by activated sludge. A tertiary treatment by coagulation (with aluminum salts) / flocculation / flotation permits to decrease the arsenic concentration in the effluent according to the operating conditions
38

Fixace olova v alkalicky aktivovaných materiálech na bázi různých typů popílků / Fixation of the lead in alkali activated materials based on different types of ashes

Cába, Vladislav January 2020 (has links)
The aim of this work was to develop an alkali activated matrix based mainly on fly ash, to determine the ability to fix lead in these matrices, the impact of added lead on mechanical properties and to reveal the way of lead fixation in these matrices. The matrices consisted mainly of fly ash (four from fluidized bed combustion, one pulverized coal combustion) with an admixture of blast furnace slag and sodium silicate as an activator. Lechates were prepared on the basis of the ČSN EN - 12457-4 standard, lead concentrations in them were measured using an atomic emission spectrometer with inductively coupled plasma. The strengths of the samples were measured after 28 days. Images, element maps and element spectra were taken to determine the structure using a scanning electron microscope with an electron dispersion spectrometer, the samples were analyzed on an infrared spectrometer with a Furier transform, X-ray diffraction analysis and electron spectroscopy for chemical analysis were also used. The individual measurements showed that lead is accumulated in the form of hydroxide. The impact of lead doping on strength of the matrix was different for individual samples. Matrices from both types of fly ash released minimal amounts of lead into leachates, so it is possible to use them to fixate lead.
39

Beneficial Utilization of Municipal Solid Waste Incineration Ashes as Sustainable Road Construction Materials

Tasneem, Kazi 01 January 2014 (has links)
Incineration of municipal solid waste (MSW) is common for energy recovery, and management of municipal solid waste incineration (MSWI) ashes has received a growing attention around the world. In the U.S., generation of MSW has increased up to 65% since 1980, to the current level of 251 million tons per year with 53.8% landfilled, 34.5% recycled and composted, and 11.7% incinerated with energy recovery. In the process of incineration, MSWI ash is being produced as byproducts; about 80 to 90% of the MSWI ash is bottom ash (BA) and 10 to 20% is fly ash (FA) by weight. The current practice of the U.S. is to combine both BA and FA to meet the criteria to qualify as non-hazardous, and all combined ashes are disposed in landfills. European countries have utilized MSWI BA as beneficial construction materials by separating it from FA. The FA is mostly limited to landfill disposal as hazardous material due to its high content of toxic elements and salts. BA has been actively recycled in the areas of roadbed, asphalt paving, and concrete products in many of European and Asian countries. In those countries, recycling programs (including required physical properties and environmental criteria) of ash residue management have been developed so as to encourage and enforce the reuse of MSWI ashes instead of landfill disposal. Moreover, many studies have demonstrated the beneficial use of MSWI ashes as engineering materials with minimum environmental impacts. On the other hand, the U.S. has shown a lack of consistent and effective management plans, as well as environmental regulations for the use of MSWI ashes., Due to persistent uncertainty of engineering properties and inconsistency in the Federal and State regulations in the U.S., however, the recycling of the MSWI ashes has been hindered and they are mostly disposed in landfills. In this research work, current management practice, existing regulations, and environmental consequences of MSWI ashes utilization are comprehensively reviewed worldwide and nationwide with an emphasis of the potential area of its utilization in asphalt paving and concrete product. This research also entails a detailed chemical and microstructural characterization of MSWI BA and FA produced from a Refuse Derived Fuel (RDF) facility in Florida so that the MSWI ash is well characterized for its beneficial uses as construction materials. The material characterization includes Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) techniques. In addition, leaching experiments have been conducted to investigate the environmental properties (e.g. leachate concentration) of BA and ash-mixed hot mix asphalt (HMA) and Portland cement concrete (PCC). Leaching results reveals the reduced leaching potential of toxic material from MSWI ashes while incorporated in HMA and PCC. Lastly, a preliminary experimental approach has been devised for the vitrification of FA which is a promising thermal process of transferring material into glassy state with higher physical and chemical integrity to reduce toxicity so that utilization of FA can be possible.
40

Nutrient availability in mineral sand tailings amended with yard waste compost and wood ash

Mankolo, Regine Ndole 10 June 2009 (has links)
Mine tailings result from surface mining coastal plain soils and sediments and are redeposited in a slurry form to the mined area. Mine tailing contains a low amount of organic matter, a low pH, and a high P fixation capacity. This research was carried out in the Atlantic Coastal Plain region to determine if mine tailings reclamation could be accomplished by utilization of yard waste compost and wood ash. Yard waste compost was used to increase the organic matter content and wood to increase pH of the mine tailings. Field research was conducted to determine the effect of yard waste compost and wood ash incorporation into mine tailings on (Zea mays L.) and peanut (Arachis hypogaea) yields. Levels of yard waste compost applied to the mine tailings were 1, 2, 4, 6, 8, and 12% by weight, and wood ash was applied twice at a rate of 2.4 t ha⁻¹. Increases in corn and peanut yields on the mine tailings were attributed to increased available water from the application of yard waste compost and to increased pH from the application of wood ash. Successful use of the yard waste compost and wood ashes for reclamation of the mine tailing is shown by the higher peanut yields on the tailings soils than adjacent natural soils. Although the corn grain yields were relatively high (up to 7830 kg ha⁻¹) where yard waste compost and wood ash were applied to the tailings, the overall corn grain yields were higher on the adjacent natural soil. Probable reasons for lower corn grain on the tailings were inadequate available water at times of maximum need and N and/or P deficiencies. Zinc deficiency was induced in corn plants by the high level of P fertilization required to overcome the high P fixation capacity of the mine tailings. The Zn deficiency could be corrected by either foliar or broadcast-disk in application of ZnSO₄. / Master of Science

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