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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.
1

Estudo da remoção de Nitrogênio Amoniacal por processo de arraste com ar (air stripping) em lixiviado de aterro sanitário.

BASTOS, F. A. 15 September 2011 (has links)
Made available in DSpace on 2018-08-24T22:53:15Z (GMT). No. of bitstreams: 1 tese_5199_Dissertação definitiva Felipe.pdf: 3695373 bytes, checksum: 835da901132eebe5561ff320277b9841 (MD5) Previous issue date: 2011-09-15 / O lixiviado de aterro sanitário possui alto potencial poluidor, com elevadas concentrações de cloretos, matéria orgânica e nitrogênio amoniacal. Seu processo de tratamento é muito complexo e geralmente envolve diferentes tecnologias. Devido à sua eficácia, o stripping é um tratamento amplamente utilizado para a remoção de NH3 de lixiviado. Esta pesquisa focou no processo de air stripping para remoção de amônia do lixiviado produzido na Central de Tratamento de Resíduos Vila Velha, CTRVV. Para tanto, as influências da variação de pH e da vazão de ar sobre a resposta do processo foram consideradas. Além disso, abordou a relação entre as remoções de alcalinidade total e nitrogênio amoniacal, bem como a formação de espuma. Para realização da parte experimental, foram realizados ensaios com 1 L de lixiviado, usando torres de arraste de com 90 cm de altura e 10 cm de diâmetro interno, em temperatura ambiente e tempo de batelada de 4 h. O experimento foi dividido em duas etapas. A Etapa I teve por objetivo direcionar metodologicamente o procedimento experimental. A Etapa II foi planejada a partir dos conhecimentos obtidos na Etapa I. Os resultados apresentaram eficiências de remoção de amônia 56%, 72% e 83% para as taxas de vazões de ar 2 NL.L-1.min-1, 5 NL.L-1.min-1 e 10 NL.L-1.min-, respectivamente. Com as variações do pH natural da amostra, pH 10, pH 11, e pH 12, obteve-se uma diferença média de 6%, entre os ensaios, sendo que o maior eficiência média foi de 75% para pH 12. Concluiu-se que a taxa de vazão de 5 NL.L-1.min-1 foi a mais adequada para remoção de amônia em lixiviado e a aplicação do pH inicial igual a 10 apresentou ser a mais vantajosa, que para pH 11 e pH 12.
2

Evaluation of physico-chemical pretreatment methods for landfill leachate prior to sewer discharge

Poveda, Mario 10 April 2015 (has links)
The City of Winnipeg, MB currently hauls by truck the leachate from the landfill, to be co-treated with the municipal wastewater at a wastewater treatment plant. Pre-treating the leachate with physico-chemical methods would allow for direct discharge to the sewer system, avoiding transportation. The goal of this research is to evaluate the effectiveness of different pre-treatment options as well as their impact on a biological nutrient removal system. In Phase I, the four pre-treatment options evaluated were air stripping, chemical coagulation, electro-coagulation and advanced oxidation with sodium ferrate. Chemical coagulation and air stripping reported the best COD and ammonia removal rates, respectively. Phase II evaluated the effectiveness of the selected pre-treatment methods in the response of a biological treatment system. The pre-treatment was successful in allowing complete nitrification by lowering the influent ammonia concentration. However, if the ratio of leachate to wastewater is low enough; pre-treatment may not be needed as the dilution lowers the impact of the leachate’s higher concentrations.
3

Recuperação da amônia liberada no processo de \"air stripping\" aplicado ao tratamento do lixiviado de aterros sanitários / Recovery of ammonia released from air stripping process applied to sanitary landfill leachate treatment

Ferraz, Fernanda de Matos 26 March 2010 (has links)
O lixiviado de aterros sanitários é um efluente líquido poluente devido, principalmente, à sua elevada concentração de amônia. Seu tratamento faz-se necessário para que sejam atendidas as exigências das legislações ambiental e trabalhista, além de minimizados os impactos ambientais de seu lançamento nos corpos d\'água. Esta pesquisa propõe a remoção da amônia presente no lixiviado por meio do processo físico-químico \"air stripping\", que promove a transferência da amônia da fase líquida para gasosa. Para que não se contribua com a poluição atmosférica, o efluente gasoso do \"air stripping\" deve ser tratado em solução de ácido sulfúrico ou água. A neutralização da amônia com solução de ácido sulfúrico gera o sulfato de amônio, e com água, a aquamônia. Tais subprodutos podem ser usados como fertilizantes. Nesta pesquisa, para remoção da amônia do lixiviado foi utilizada uma torre de PVC, com 2,24 m de altura e 15 cm de diâmetro, recheada com anéis do tipo Rashing de polietileno corrugados, com diâmetro de 1,5 cm e 5 cm de comprimento. As vazões de ar utilizadas foram 1200, 1600 e 3600 L/h e as vazões de lixiviado foram 18 e 30 L/h. Para ajuste no pH do lixiviado, utilizou-se hidróxido de cálcio (padrão analítico) e cal comercial. Os fluxos de líquido e ar eram em contracorrente. Para o recolhimento da amônia foram usados dois frascos de 6 L, preenchidos com 4 L de solução de ácido sulfúrico 0,4 mol/L ou água. Os resultados obtidos indicaram remoção praticamente completa de toda a amônia contida no lixiviado. Nas diferentes condições operacionais avaliadas, a concentração de amônia remanescente no lixiviado foi igual ou inferior aos 20 mg/L determinados pela Resolução 397/08 do CONAMA. Quanto ao recolhimento da amônia, a eficiência média obtida nos frascos lavadores próxima a 80%, tanto ) quando utilizada a solução de ácido sulfúrico 0,4 mol/L quanto quando utilizada água. / Sanitary landfill leachate is a pollutant liquid effluent mainly due to its high ammonia concentration. Its treatment is necessary due to environmental and labour legislation requirements, besides prevention of environmental impacts of leachate release in water bodies. This research proposes ammonia removal from leachate by air stripping process, which transfers ammonia from liquid to gaseous phase. In order to prevent atmospheric pollution, air stripping gaseous effluent must be treated with sulphuric acid solution or water. Ammonia neutralization by sulfuric generates ammonium sulfate and by water, aquammonia is generated. Such by-products may be used as fertilizer. In this research, in order to remove leachate ammonia it was used a PVC tower of 2.24 m high and 15 cm diameter, packed with Rashing rings of corrugated polyethylene of 1.5 cm diameter and 5 cm length. Air flows were 1200, 1600 and 3600 L/h and leachete flows were 18 e 30 L/h. Calcium carbonate (standard grade) and commercial hydrated lime were used for pH adjustments. Air and liquid flows were countercurrent. In order to recover ammonia, two flasks of 6 L were used and filled with 4 L of 0.4 mol/L sulfuric acid solution or water. Results showed that ammonia was almost completely removed from leachate. In all operational conditions evaluated, remaining ammonia concentration in leachate was equal or less than 20 mg/L, value established by Resolution 397/08 of Brazilian Council of the Environment. Ammonia recovery with water or a 0.4 mol/L sulfuric acid solution was about 80%.
4

Avaliação do tratamento combinado de lixiviado de aterro sanitário e esgoto sanitário em sistema de lodos ativados / Evaluation of the combined treatment of landfill leachate and domestic sewage in activated sludge system

Albuquerque, Edilincon Martins de 05 June 2012 (has links)
Um dos principais resíduos gerados nos aterros é o lixiviado, que possui elevada concentração de matéria orgânica biodegradável e refratária e de matéria inorgânica, como nitrogênio amoniacal e metais pesados. O tratamento combinado de lixiviado com esgoto sanitário tem sido utilizado em algumas estações de tratamento de esgoto (ETE) brasileiras. No entanto, o processo ainda sofre vários questionamentos e incertezas, especialmente sobre os efeitos da adição do lixiviado sobre o sistema de tratamento. Nesse contexto, o presente trabalho visou avaliar a eficiência do tratamento combinado de lixiviado/esgoto em sistema de lodos ativados, em diferentes condições. Na primeira etapa desta pesquisa, foram realizados experimentos de tratabilidade em escala de bancada (regime de batelada) utilizando as proporções volumétricas de 0% (controle), 0,2%, 2% e 5% de lixiviado em diferentes condições experimentais. Dentre eles, o Experimento 2 (lixiviado pré-tratado por alcalinização e air stripping) se mostrou mais viável tecnicamente, alcançando eficiências de remoção da DBO, da DQO e do COD acima de 97, 82, 60%, respectivamente, até a proporção de 2% de lixiviado pré-tratado. Na segunda etapa da pesquisa, foi avaliada a tratabilidade utilizando reatores em escala piloto (regime contínuo) tratando esgoto sanitário com 2% (P1) e 0% (P2-controle) de lixiviado pré-tratado, com relação microrganismo-alimento de 0,22 kgDBO/kgSSV.dia, tempo de detenção hidráulica de 24 horas e idade do lodo de 20 dias. Os resultados indicaram viabilidade do tratamento nas condições estudadas com 2% de lixiviado pré-tratado, cujas eficiências médias de remoção da DBO, da DQO, do COD foram de 93, 84 e 60%, respectivamente. Esta pesquisa foi desenvolvida com apoio financeiro (Processo N° 2010/51955-2) da Fundação de Amparo à Pesquisa de São Paulo (FAPESP). / The leachate is one of the main wastes generated in landfills, it has a high concentration of biodegradable and refractory organic matter and inorganic matter, such as ammonia and heavy metals. The combined treatment of leachate with sewage has been used in various sewage treatment plants in Brazil. However, there are still many questions and uncertainties about the process, especially the effects of adding leachate on the treatment system. In this context, this study aimed at evaluating the efficiency of combined treatment of leachate/sewage in activated sludge under different conditions. In the first stage of this research, treatability experiments were carried out in a bench scale (SBR) using the volumetric proportions of 0% (control), 0.2%, 2% and 5% leachate under different experimental conditions. The Experiment 2 (leachate pretreated by alkalinization and air stripping) was more technically feasible, achieving efficiencies of removal of BOD, COD and DOC above 97, 82, 60%, respectively, until the proportion of 2% pre-treated leachate. In the second stage of the research was evaluated the treatability using pilot-scale reactors (continuous flow) for sewage treatment with 2% (P1) and 0% (P2-control) leachate pretreated. The operational parameters adopted were food-microorganism rate of 0.22 kgDBO/ kgSSV.d, hydraulic retention time of 24 hours and the sludge retention time of 20 days. The results indicated the viability of the combined treatment with 2% leached pretreated, whose average efficiency of removing BOD, COD, DOC were 93, 84 and 60% respectively. This research was developed with financial support (case No. 2010/2-51955) of Fundação de Amparo à Pesquisa de São Paulo (FAPESP).
5

Avaliação do tratamento combinado de lixiviado de aterro sanitário e esgoto sanitário em sistema de lodos ativados / Evaluation of the combined treatment of landfill leachate and domestic sewage in activated sludge system

Edilincon Martins de Albuquerque 05 June 2012 (has links)
Um dos principais resíduos gerados nos aterros é o lixiviado, que possui elevada concentração de matéria orgânica biodegradável e refratária e de matéria inorgânica, como nitrogênio amoniacal e metais pesados. O tratamento combinado de lixiviado com esgoto sanitário tem sido utilizado em algumas estações de tratamento de esgoto (ETE) brasileiras. No entanto, o processo ainda sofre vários questionamentos e incertezas, especialmente sobre os efeitos da adição do lixiviado sobre o sistema de tratamento. Nesse contexto, o presente trabalho visou avaliar a eficiência do tratamento combinado de lixiviado/esgoto em sistema de lodos ativados, em diferentes condições. Na primeira etapa desta pesquisa, foram realizados experimentos de tratabilidade em escala de bancada (regime de batelada) utilizando as proporções volumétricas de 0% (controle), 0,2%, 2% e 5% de lixiviado em diferentes condições experimentais. Dentre eles, o Experimento 2 (lixiviado pré-tratado por alcalinização e air stripping) se mostrou mais viável tecnicamente, alcançando eficiências de remoção da DBO, da DQO e do COD acima de 97, 82, 60%, respectivamente, até a proporção de 2% de lixiviado pré-tratado. Na segunda etapa da pesquisa, foi avaliada a tratabilidade utilizando reatores em escala piloto (regime contínuo) tratando esgoto sanitário com 2% (P1) e 0% (P2-controle) de lixiviado pré-tratado, com relação microrganismo-alimento de 0,22 kgDBO/kgSSV.dia, tempo de detenção hidráulica de 24 horas e idade do lodo de 20 dias. Os resultados indicaram viabilidade do tratamento nas condições estudadas com 2% de lixiviado pré-tratado, cujas eficiências médias de remoção da DBO, da DQO, do COD foram de 93, 84 e 60%, respectivamente. Esta pesquisa foi desenvolvida com apoio financeiro (Processo N° 2010/51955-2) da Fundação de Amparo à Pesquisa de São Paulo (FAPESP). / The leachate is one of the main wastes generated in landfills, it has a high concentration of biodegradable and refractory organic matter and inorganic matter, such as ammonia and heavy metals. The combined treatment of leachate with sewage has been used in various sewage treatment plants in Brazil. However, there are still many questions and uncertainties about the process, especially the effects of adding leachate on the treatment system. In this context, this study aimed at evaluating the efficiency of combined treatment of leachate/sewage in activated sludge under different conditions. In the first stage of this research, treatability experiments were carried out in a bench scale (SBR) using the volumetric proportions of 0% (control), 0.2%, 2% and 5% leachate under different experimental conditions. The Experiment 2 (leachate pretreated by alkalinization and air stripping) was more technically feasible, achieving efficiencies of removal of BOD, COD and DOC above 97, 82, 60%, respectively, until the proportion of 2% pre-treated leachate. In the second stage of the research was evaluated the treatability using pilot-scale reactors (continuous flow) for sewage treatment with 2% (P1) and 0% (P2-control) leachate pretreated. The operational parameters adopted were food-microorganism rate of 0.22 kgDBO/ kgSSV.d, hydraulic retention time of 24 hours and the sludge retention time of 20 days. The results indicated the viability of the combined treatment with 2% leached pretreated, whose average efficiency of removing BOD, COD, DOC were 93, 84 and 60% respectively. This research was developed with financial support (case No. 2010/2-51955) of Fundação de Amparo à Pesquisa de São Paulo (FAPESP).
6

Recuperação da amônia liberada no processo de \"air stripping\" aplicado ao tratamento do lixiviado de aterros sanitários / Recovery of ammonia released from air stripping process applied to sanitary landfill leachate treatment

Fernanda de Matos Ferraz 26 March 2010 (has links)
O lixiviado de aterros sanitários é um efluente líquido poluente devido, principalmente, à sua elevada concentração de amônia. Seu tratamento faz-se necessário para que sejam atendidas as exigências das legislações ambiental e trabalhista, além de minimizados os impactos ambientais de seu lançamento nos corpos d\'água. Esta pesquisa propõe a remoção da amônia presente no lixiviado por meio do processo físico-químico \"air stripping\", que promove a transferência da amônia da fase líquida para gasosa. Para que não se contribua com a poluição atmosférica, o efluente gasoso do \"air stripping\" deve ser tratado em solução de ácido sulfúrico ou água. A neutralização da amônia com solução de ácido sulfúrico gera o sulfato de amônio, e com água, a aquamônia. Tais subprodutos podem ser usados como fertilizantes. Nesta pesquisa, para remoção da amônia do lixiviado foi utilizada uma torre de PVC, com 2,24 m de altura e 15 cm de diâmetro, recheada com anéis do tipo Rashing de polietileno corrugados, com diâmetro de 1,5 cm e 5 cm de comprimento. As vazões de ar utilizadas foram 1200, 1600 e 3600 L/h e as vazões de lixiviado foram 18 e 30 L/h. Para ajuste no pH do lixiviado, utilizou-se hidróxido de cálcio (padrão analítico) e cal comercial. Os fluxos de líquido e ar eram em contracorrente. Para o recolhimento da amônia foram usados dois frascos de 6 L, preenchidos com 4 L de solução de ácido sulfúrico 0,4 mol/L ou água. Os resultados obtidos indicaram remoção praticamente completa de toda a amônia contida no lixiviado. Nas diferentes condições operacionais avaliadas, a concentração de amônia remanescente no lixiviado foi igual ou inferior aos 20 mg/L determinados pela Resolução 397/08 do CONAMA. Quanto ao recolhimento da amônia, a eficiência média obtida nos frascos lavadores próxima a 80%, tanto ) quando utilizada a solução de ácido sulfúrico 0,4 mol/L quanto quando utilizada água. / Sanitary landfill leachate is a pollutant liquid effluent mainly due to its high ammonia concentration. Its treatment is necessary due to environmental and labour legislation requirements, besides prevention of environmental impacts of leachate release in water bodies. This research proposes ammonia removal from leachate by air stripping process, which transfers ammonia from liquid to gaseous phase. In order to prevent atmospheric pollution, air stripping gaseous effluent must be treated with sulphuric acid solution or water. Ammonia neutralization by sulfuric generates ammonium sulfate and by water, aquammonia is generated. Such by-products may be used as fertilizer. In this research, in order to remove leachate ammonia it was used a PVC tower of 2.24 m high and 15 cm diameter, packed with Rashing rings of corrugated polyethylene of 1.5 cm diameter and 5 cm length. Air flows were 1200, 1600 and 3600 L/h and leachete flows were 18 e 30 L/h. Calcium carbonate (standard grade) and commercial hydrated lime were used for pH adjustments. Air and liquid flows were countercurrent. In order to recover ammonia, two flasks of 6 L were used and filled with 4 L of 0.4 mol/L sulfuric acid solution or water. Results showed that ammonia was almost completely removed from leachate. In all operational conditions evaluated, remaining ammonia concentration in leachate was equal or less than 20 mg/L, value established by Resolution 397/08 of Brazilian Council of the Environment. Ammonia recovery with water or a 0.4 mol/L sulfuric acid solution was about 80%.
7

A Study for Remediation of MTBE and Diesel Contaminated Soils by Soil Heating/Air Stripping and Steam Injection/Vacuum Extraction- One Dimensional Mass Transfer Analysis and Verification

Hsien, Adren 02 August 2000 (has links)
This research reports on an experimental and theoretical study of soil heating/air stripping and steam injection/vacuum extraction for remediation of MTBE and Diesel Contaminated Soils. Two one-dimensional mass transfer models were using to simulate the process of remediaction. Contaminant kinds(MTBE and Diesel)¡A contaminant concentration (152~13,912 mg/kg soil)¡Asoil temperature(38~120¢J)¡Asteam injection pressure(0.5~1.0 atm)¡A and the mass of steam used(0.379~0.730 kg/h)were employed as the experimental factors in this study. In soil heating/air stripping study, rising soil temperature will enhance the MTBE removed efficiency¡A it was shown in the concentration of effluent gas. Further, the flow rate at outlet of column was higher than that at inlet of column, it revealed MTBE transfers from liquid phase to gas phase and was removed by gas flow. The concentration of effluent gas curve in low initial MTBE concentration test was similar with high concentration test, but the mechanisms was quiet different¡Ait need advanced adsorption test to find the reasons. In medium initial MTBE concentration test¡Athe concentration of effluent gas curve showed linear shape. When using steam injection/vacuum extraction treating MTBE contaminated soil, it showed 90¢Mefficiency can be reached in one hour. In steam injection/vacuum extraction study, it showed higher initial diesel contaminant concentration¡Ahigher initial concentration of effluent gas. Further, in high initial diesel concentration test (13.912 g diesel/kg soil test and about 5g/ kg soil tests)¡Athe concentration of effluent gas curves had a dominant drop at early time in remediation, it revealed the injection steam flow was quiet large, so diesel didn¡¦t has enough time to transfer to gas phase, that the gas couldn¡¦t been saturation at outlet of column. But in low initial diesel concentration test (about 1 g diesel/kg soil tests), the concentration of effluent gas curves showed the typical NAPL remediation curve. The different with in high and low initial concentrations might from the complex composition of diesel. Because at the early time in remediaction of high initial diesel concentration, the low carbon numbers diesel could abundantly evaporate, it caused the high concentration of effluent gas. With the remediation time go by, the low carbon numbers diesel exhaust. So the main composition of effluent gas transfer to high carbon numbers diesel, that the concentration of effluent gas curve showed the slowly decline. For high initial diesel concentration test (13.912 g diesel/kg soil)¡A the efficiency was the highest (73.7¢M). For low initial diesel concentration test (about 1 g diesel/kg soil), the efficiency was the lost (about 20¢M). Further, the remediation of diesel contaminated soil exited a rapid removed period. Under the conditions of this study, the rapid removed period could remove more than 95¢Mcontaminant of diesel removed at hold remediation time. The experiment results also showed that larger the mass of steam injection, shorter the rapid removed period, and larger the steam injection pressure, longer the rapid removed period. When using soil heating/air stripping treating diesel contaminated soil, the removed efficiency was worse 10-20¢Mthan the same initial diesel contaminated concentration. In simulating remediation process, the prediction with the MTBE measured concentration yielded good agreement in NAPL model. But to get the better fit of diesel in NAPL model, it might set the ¡§could removed mass¡¨ to initial condition of model. In non-NAPL model, MTBE also showed good agreement with model, and the model enabled the prediction of the initial contaminant level in the soil.
8

Ammonia Removal and Recovery from Wastewater Using Natural Zeolite: An Integrated System for Regeneration by Air Stripping Followed Ion Exchange

Deng, Qiaosi 20 January 2014 (has links)
This study revealed that ammonium ion exchange of natural zeolite could be a feasible method of nitrogen removal and recovery from permeate from anaerobic membrane bioreactors (AnMBRs). NaCl concentrations optimized for chemical regeneration in batch experiments did not match those in continuous column tests. Instead, the mass ratio of Na+ to Zeolite-NH4+-N was significant for improving regeneration efficiency in column experiments; this mass ratio was 750 g Na+/g Zeolite-NH4+-N required for regeneration efficiency over 90% in 2 hours at pH 9. ???To decrease the NaCl dose in regeneration of exhausted zeolite, a high pH regeneration method was developed using an NaCl concentration of 10 g/L at pH 12 (the mass of Na+ to Zeolite-NH4+-N of 4.2 ) which achieved a regeneration efficiency about 85%. The recovery of ammonium nitrogen from the exhausted zeolite was assessed with air stripping followed by ammonia collection in an acid scrubber. The effects of shaking and air stripping were investigated in batch tests and the results showed the superiority of air stripping over shaking. Liquid circulation and air flow rates were varied for optimization of ammonia recovery in a continuous zeolite-packed column combined with a regeneration chamber and a stripping column. The liquid circulation rate had no significant effect on either the regeneration efficiency or the ammonia transfer efficiency from ammonium nitrogen to ammonia gas, while the ammonia transfer efficiency significantly increased with the air flow rate.??? Furthermore, the effect of pH on ammonia recovery was tested. Both the regeneration efficiency and the ammonia transfer efficiency were significantly improved with increasing pH. When the pH was increased from 9.5 to 12, the regeneration efficiency increased from 9.2% to 84% and the ammonia transfer efficiency increased from 54% to 92%. The nitrogen recovery process that combines zeolite ammonium exchange and air stripping can decrease chemical costs for regeneration of exhausted zeolite and efficiently collect ammonium nitrogen to be reused as fertilizers. Hence, the integrated nitrogen process can resolve the challenge of nitrogen removal in anaerobic membrane bioreactors treating organic wastewater in sustainable manners.
9

Air stripping and biological treatment of ammonium sulfate wastewater from the caprolactam manufacturing process

Smith, Roberta J. January 1994 (has links)
M.S.
10

TREATMENT OF MTBE CONTAMINATED WATERS USING AIR STRIPPING AND ADVANCED OXIDATION PROCESSES

RAMAKRISHNAN, BALAJI January 2005 (has links)
No description available.

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