Duas metodologias distintas foram desenvolvidas para a determinação de chumbo em Resíduos de Disparos de Armas de Fogo (RDAF) utilizando microeletrodo de ouro. Na primeira delas, a superfície eletródica foi modificada com filme de bismuto em meio alcalino (pH = 13) e na outra as análises foram realizadas com microeletrodo não modificado em meio ácido com cloreto. Os RDAF foram coletados do alvo atingido pela bala e das mãos do atirador. Dos alvos, foi recortada uma região próxima ao orifício feito pela bala. Já para remoção dos RDAF das mãos do atirador, foi utilizado um algodão embebido em solução de EDTA 2% (m/v). Os resíduos foram submetidos a um processo de extração que consistiu em adicionar 10 mL de solução de HNO3 10% (m/m) ao frasco contendo o alvo ou o algodão com os RDAF. Em seguida, a mistura foi submetida ao ultrassom por 2 horas a uma temperatura de 60°C. As amostras provenientes dos alvos foram analisadas com o microeletrodo de ouro modificado com bismuto em meio alcalino por voltametria de redissolução anódica. Com essa metodologia, obteve-se um limite de detecção (3σ/sensibilidade) de 12,5 nmol L-1, uma faixa linear entre 40 e 6700 nmol L-1 e um desvio padrão relativo de 3,4% (n = 12). Foi possível analisar amostras provenientes de duas armas diferentes (pistola 9 mm e revólver 0.38 polegadas) e três munições distintas (normal, spl® e CleanRange®). Constatou-se um aumento da quantidade de chumbo presente nos resíduos à medida que o atirador se aproxima do alvo e que os valores dependem da arma e munição utilizadas. Com a outra metodologia as análises foram realizadas na própria solução extratora, com adição de cloreto, sem qualquer modificação da superfície eletródica. Neste caso, o limite de detecção (3σ/sensibilidade) encontrado foi de 1,7 nmol L-1, a faixa linear ficou entre 10 e 100 nmol L-1 e o desvio padrão relativo de 10 medidas foi 2,5%. Foram analisados resíduos provenientes das mãos dos atiradores de quatro diferentes armas (revólver 0.38 polegadas, espingardas calibre 12, 22 e 38) e de seis diferentes munições (CleanRange®, normal, semi-enjaquetada, 3T®, Eley® e CBC®). Os resultados obtidos com a metodologia proposta foram comparados com aqueles oriundos de análise por espectroscopia de absorção atômica e houve concordância em um nível de confiança de 95%. Foi também realizada uma análise quimiométrica das soluções contendo os RDAF. Os resultados mostraram a possibilidade de discriminação em relação à arma e munição utilizadas. Os filmes formados nas superfícies eletródicas foram estudados utilizando o Microscópio Eletroquímico de Varredura (SECM), a Microbalança Eletroquímica de Cristal de Quartzo (MECQ) e o Microscópio Eletrônico de Varredura (MEV). A deposição dos filmes de bismuto, chumbo e bismuto/chumbo em meio alcalino ocorre de forma heterogênea e esses filmes reagem com oxigênio e ferricianeto. Em meio ácido, a presença do cloreto na solução de depósito do filme de chumbo provoca aumento na rugosidade do filme, com consequente melhoria no sinal analítico. Também se observou que o cloreto facilita o processo de redissolução do filme de chumbo. / Two different methodologies were developed to analyze lead from gunshot residues (GSR) with a gold microelectrode: modification of the electrode surface with a bismuth film in alkaline solution (pH = 13) and use of an unmodified gold microelectrode in acidic media with chloride. GSR were collected from cloth targets and shooters\' hand after test firing. From the targets, a region close to the bullet hole was cutted off. GSR were removed from the shooters\' hand using a cotton swab embedded in a 2% (m/v) EDTA solution. The target and the cotton swab were placed in a steril vial containing 10 mL of a 10% (m/m) HNO3 solution to extract the GSR. Then, all vials were placed in the ultrasound for 2 hours at 60°C. Samples from the targets were analyzed with a gold microelectrode modified with a bismuth film in alkaline solution by anodic stripping voltammetry with a detection limit of 12.5 nmol L-1 (3σ/slope), linear range between 40 and 6700 nmol L-1 and a relative standard deviation of 3.4% (n = 12). Two different handguns (pistoll 9 mm and a revolver 0.38 inches) and tree different ammunition (normal, spl® and CleanRange®) were analyzed and the lead amount was dependent on the gun and ammunition used in the tests. An increase in the amount of lead from the GSR was observed as the distance between the shooter and the target decreased. Lead analyses were also performed in the extraction solution with bare gold microelectrodes in the presence of chloride ions. In this case, the detection limit was 1.7 nmol L-1 (3σ/slope), the linear range lied between 10 and 100 nmol L-1 and the relative standard deviation for 10 measurements was 2.5%. GSR residues form four different guns (revolver 0.38 inches, 12 caliber pump, a repeating rifle 0.38 and a semi automatic .22 caliber rifle) and six different ammunitions (CleanRange®, normal, semi jacketed, 3T®, Eley® and CBC®) were analyzed. The results obtained with the proposed methodology were compared with those from atomic absorption spectroscopy analysis and the paired t-test student indicated that there was no significant difference between the results obtained with both methods at a 95% confidence level. A chemometric analysis was also performed and the results showed the possibility to discriminate the guns and the ammunitions used. Metallic flms formed onto the electrode surface were studied by using Scanning Electrochemial Microscopy (SECM), Electrochemical Quartz Crystal Microbalance (EQCM) and Scanning Electronic Microscopy (SEM). The deposition of bismuth, lead and bismuth/lead films in alkaline solution is heterogeneous and the films react with oxygen and ferricyanide. In acidic media, the presence of chloride ions in the depositing solution causes an increase in the film roughness and facilitates the lead film dissolution

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%.

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).

Duas metodologias distintas foram desenvolvidas para a determinação de chumbo em Resíduos de Disparos de Armas de Fogo (RDAF) utilizando microeletrodo de ouro. Na primeira delas, a superfície eletródica foi modificada com filme de bismuto em meio alcalino (pH = 13) e na outra as análises foram realizadas com microeletrodo não modificado em meio ácido com cloreto. Os RDAF foram coletados do alvo atingido pela bala e das mãos do atirador. Dos alvos, foi recortada uma região próxima ao orifício feito pela bala. Já para remoção dos RDAF das mãos do atirador, foi utilizado um algodão embebido em solução de EDTA 2% (m/v). Os resíduos foram submetidos a um processo de extração que consistiu em adicionar 10 mL de solução de HNO3 10% (m/m) ao frasco contendo o alvo ou o algodão com os RDAF. Em seguida, a mistura foi submetida ao ultrassom por 2 horas a uma temperatura de 60°C. As amostras provenientes dos alvos foram analisadas com o microeletrodo de ouro modificado com bismuto em meio alcalino por voltametria de redissolução anódica. Com essa metodologia, obteve-se um limite de detecção (3σ/sensibilidade) de 12,5 nmol L-1, uma faixa linear entre 40 e 6700 nmol L-1 e um desvio padrão relativo de 3,4% (n = 12). Foi possível analisar amostras provenientes de duas armas diferentes (pistola 9 mm e revólver 0.38 polegadas) e três munições distintas (normal, spl® e CleanRange®). Constatou-se um aumento da quantidade de chumbo presente nos resíduos à medida que o atirador se aproxima do alvo e que os valores dependem da arma e munição utilizadas. Com a outra metodologia as análises foram realizadas na própria solução extratora, com adição de cloreto, sem qualquer modificação da superfície eletródica. Neste caso, o limite de detecção (3σ/sensibilidade) encontrado foi de 1,7 nmol L-1, a faixa linear ficou entre 10 e 100 nmol L-1 e o desvio padrão relativo de 10 medidas foi 2,5%. Foram analisados resíduos provenientes das mãos dos atiradores de quatro diferentes armas (revólver 0.38 polegadas, espingardas calibre 12, 22 e 38) e de seis diferentes munições (CleanRange®, normal, semi-enjaquetada, 3T®, Eley® e CBC®). Os resultados obtidos com a metodologia proposta foram comparados com aqueles oriundos de análise por espectroscopia de absorção atômica e houve concordância em um nível de confiança de 95%. Foi também realizada uma análise quimiométrica das soluções contendo os RDAF. Os resultados mostraram a possibilidade de discriminação em relação à arma e munição utilizadas. Os filmes formados nas superfícies eletródicas foram estudados utilizando o Microscópio Eletroquímico de Varredura (SECM), a Microbalança Eletroquímica de Cristal de Quartzo (MECQ) e o Microscópio Eletrônico de Varredura (MEV). A deposição dos filmes de bismuto, chumbo e bismuto/chumbo em meio alcalino ocorre de forma heterogênea e esses filmes reagem com oxigênio e ferricianeto. Em meio ácido, a presença do cloreto na solução de depósito do filme de chumbo provoca aumento na rugosidade do filme, com consequente melhoria no sinal analítico. Também se observou que o cloreto facilita o processo de redissolução do filme de chumbo. / Two different methodologies were developed to analyze lead from gunshot residues (GSR) with a gold microelectrode: modification of the electrode surface with a bismuth film in alkaline solution (pH = 13) and use of an unmodified gold microelectrode in acidic media with chloride. GSR were collected from cloth targets and shooters\' hand after test firing. From the targets, a region close to the bullet hole was cutted off. GSR were removed from the shooters\' hand using a cotton swab embedded in a 2% (m/v) EDTA solution. The target and the cotton swab were placed in a steril vial containing 10 mL of a 10% (m/m) HNO3 solution to extract the GSR. Then, all vials were placed in the ultrasound for 2 hours at 60°C. Samples from the targets were analyzed with a gold microelectrode modified with a bismuth film in alkaline solution by anodic stripping voltammetry with a detection limit of 12.5 nmol L-1 (3σ/slope), linear range between 40 and 6700 nmol L-1 and a relative standard deviation of 3.4% (n = 12). Two different handguns (pistoll 9 mm and a revolver 0.38 inches) and tree different ammunition (normal, spl® and CleanRange®) were analyzed and the lead amount was dependent on the gun and ammunition used in the tests. An increase in the amount of lead from the GSR was observed as the distance between the shooter and the target decreased. Lead analyses were also performed in the extraction solution with bare gold microelectrodes in the presence of chloride ions. In this case, the detection limit was 1.7 nmol L-1 (3σ/slope), the linear range lied between 10 and 100 nmol L-1 and the relative standard deviation for 10 measurements was 2.5%. GSR residues form four different guns (revolver 0.38 inches, 12 caliber pump, a repeating rifle 0.38 and a semi automatic .22 caliber rifle) and six different ammunitions (CleanRange®, normal, semi jacketed, 3T®, Eley® and CBC®) were analyzed. The results obtained with the proposed methodology were compared with those from atomic absorption spectroscopy analysis and the paired t-test student indicated that there was no significant difference between the results obtained with both methods at a 95% confidence level. A chemometric analysis was also performed and the results showed the possibility to discriminate the guns and the ammunitions used. Metallic flms formed onto the electrode surface were studied by using Scanning Electrochemial Microscopy (SECM), Electrochemical Quartz Crystal Microbalance (EQCM) and Scanning Electronic Microscopy (SEM). The deposition of bismuth, lead and bismuth/lead films in alkaline solution is heterogeneous and the films react with oxygen and ferricyanide. In acidic media, the presence of chloride ions in the depositing solution causes an increase in the film roughness and facilitates the lead film dissolution

Oito blocos transportáveis para calibração foram construídos para serem utilizados como padrões de concentração na calibração de espectrômetros gama portáteis e aerotransportados. Todo o procedimento de construção é descrito em detalhe. Os blocos, com dimensões de 1 m x 1 m x 0,30 m e massas variando entre 593 kg e 673 kg, devem a sua radioatividade à adição de diferentes quantidades de feldspato potássico (ortoclásio), caldasito e areia monazítica à massa de concreto. As concentrações de potássio, urânio e tório variam significativamente de um bloco para outro atingindo valores máximos de 5,7% de K, 45,6 ppm eU e 137 ppm eTh. A distribuição do fluxo de radiação gama proveniente da superfície dos blocos de concreto e a magnitude das heterogeneidades na concentração dos elementos radioativos foi determinada experimentalmente. Como exemplo de aplicação apresenta-se o resultado da calibração de um espectrômetro gama portátil. / Eight transportable calibration pads were built in to be used as concentration standards for portable and airborne gamma spectrometers calibrations. The pads construction procedure is described in full detail. The pads, with dimensions of 1 m x 1 m x 0,30 m and masses between 593 kg and 673 kg were made radioactive by the addition of different amounts of k-feldspar, caldasite and monazitic sand to the concrete masses. The potassium, uranium and thorium concentration vary significantly in the pads, reaching maximum values of 5,7% of K, 45,6 ppm eU and 137 ppm eTh. The distribution of the gamma radiation flux from the pads surfaces and the heterogeneity magnitudes of the radioactive elements concentration were experimentally established. An example of gamma spectrometer calibration is presented.

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).

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%.

Les travaux présentés dans cette thèse visent à étudier les interfaces "nanocatalyseur/glucose" et "enzyme/O2" d'une biopile hybride. Dans ce cadre, une nouvelle méthode de synthèse de nanoparticules à base d'or et de platine a été développée. Ces nanomatériaux ont été caractérisés par différentes méthodes physicochimiques pour connaître leur taille, leur morphologie et leur dispersion dans un substrat carboné (Vulcan XC72R). La surface active de chaque électrode a été déterminée par voltammétrie cyclique et par CO stripping. Il a été montré que dans les catalyseurs AuxPty, l'or a un effet promoteur sur le platine vis-à-vis de l'oxydation du glucose. Le catalyseur Au70Pt30 présente la meilleure activité catalytique. L'étude par spectroélectrochimie a permis de déterminer que la B–gluconolactone est le produit primaire de l'oxydation du glucose qui procède à bas potentiel par la déshydrogénation du carbone anomérique sur le platine. La réaction de réduction de O2 a été catalysée par une enzyme, la bilirubine oxydase (BOD). Pour faciliter le transfert électronique, deux médiateurs : ABTS et un complexe d'osmium ont été encapsulés avec l'enzyme dans une matrice de Nafion® pour créer les interfaces : BOD/ABTS/O2 et BOD/Os/O2. L'étude voltammétrique des deux médiateurs en milieu tampon phosphate a révélé deux systèmes quasi-réversibles avec des potentiels apparents proches du potentiel redox du site T1 de la BOD. Bien que difficilement comparables en termes de densité de courant au catalyseur constitué de nanoparticules de platine, les cathodes enzymatiques permettent de catalyser à quatre électrons la réduction de O2 à des potentiels très proches du potentiel de Nernst. / The work developed in this thesis concerns the study of the behavior of redox reactions at the interfaces "nanocatalyst/glucose" and "enzyme/O2" for a hybrid Biofuel Cell. In this framework, a novel synthesis method of based gold and platinum nanoparticles has been achieved. These synthesized nanomaterials were characterized by different physicochemical techniques to determine their size, morphology and their dispersion in Vulcan XC72R used as substrate. The active surface area of each electrode material was determined by cyclic voltammetry and CO stripping. It has been shown that in the bimetallic catalyst gold promotes platinum activity towards the glucose oxidation. The bimetallic composition Au70Pt30 exhibits the better efficiency. The study by spectroelectrochemistry determined that the B-gluconolactone is the primary product of the glucose oxidation which proceeds at low potential by the dehydrogenation of anomeric carbon on platinum. The reduction reaction of O2 was catalyzed by an enzyme, bilirubin oxidase (BOD). Mediated electronic transfer was performed with two redox mediators, ABTS and an Osmium complex (Os). They have been encapsulated with the enzyme in a Nafion® matrix to construct the interfaces: BOD/ABTS/O2 and BOD/Os/O2. The voltammetric study of the mediators in phosphate buffer revealed two quasi-reversible systems with an apparent potential close to the theoretical potential of the T1 BOD center. Although hardly comparable in terms of current density with the Pt nanocatalyst the O2 reduction is a four electron reaction at the cathodes BOD/ABTS and BOD/Os which deliver an electrode potential close to the Nernst one.

We investigate the uses of gravitational lensing for analysing the dark matter haloes around galaxies, comparing galaxies within groups and clusters to those in the field. We consider two cases: when only photometric redshift data is available, and when spectroscopic redshift data is available for a sufficiently large sample of galaxies. For the case of data with photometric redshifts, we analyse the CFHTLenS dataset. This dataset is derived from the CFHTLS-Wide survey, and encompasses 154 deg^2 of high-quality shape data. Using the photometric redshifts to estimate local density, we divide the sample of lens galaxies with stellar masses in the range 10^9 Msun to 10^10.5 Msun into those likely to lie in high-density environments (HDE) and those likely to lie in low-density environments (LDE). Through comparison with galaxy catalogues extracted from the Millennium Simulation, we show that the sample of HDE galaxies should primarily (~61%) consist of satellite galaxies in groups, while the sample of LDE galaxies should consist of mostly (~87%) non-satellite (field and central) galaxies. Comparing the lensing signals around samples of HDE and LDE galaxies matched in stellar mass, we show that the subhaloes of HDE galaxies are less massive than those around LDE galaxies by a factor 0.65+/-0.12, significant at the 2.9 sigma level. A natural explanation is that the haloes of satellite galaxies are stripped through tidal effects in the group environment. Our results are consistent with a typical tidal truncation radius of ~40 kpc. For the case of data with spectroscopic redshifts, we analyse the GAMA-I and the ongoing GAMA-II surveys. We demonstrate the possibility of detecting tidal stripping of dark matter subhaloes within galaxy groups using weak gravitational lensing. We have run ray-tracing simulations on galaxy catalogues from the Millennium Simulation to generate mock shape catalogues. The ray-tracing catalogues assume a halo model for galaxies and groups, using various models with different distributions of mass between galaxy and group haloes to simulate different stages of group evolution. Using these mock catalogues, we forecast the lensing signals that will be detected around galaxy groups and satellite galaxies, as well as test two different methods for isolating the satellites' lensing signals. A key challenge is to determine the accuracy to which group centres can be identified. We show that with current and ongoing surveys, it will possible to detect stripping in groups of mass 10^12 Msun to 10^15 Msun.

Magnetic deflection techniques have been employed to measure proton angular distributions from some (d,p) and (t,p) reactions. In many cases the distributions exhibit typical stripping patterns and their analysis in terms of plane wave and distorted wave theories of stripping has enabled spin and parity assignments to be made for a number of excited nuclear levels. These theories are briefly outlined in Chapter 1 of this thesis and the experimental procedures are described in Chapter 2. The (d,p) reaction has been studied at an incident energy of 3 MeV with target nuclei B¹⁰, B¹¹, C¹², C¹⁴ and O¹⁶ and an account of this investigation is given in Chapter 3. Although the plane wave theory gives a good account of the angular distributions corresponding to the low-Q transitions (say Q ≤ 2 MeV) it is not a good approximation for the high-Q transitions. This is in accord with Wilkinson's suggestion that distortion effects should be quite small even at low deuteron bombarding energies providing also that the reaction Q-value is low. Agreement with the high-Q ground state distribution for B¹¹ could only be obtained with distorted wave theory if a cut-off radius were used. This may indicate the need for taking into account finite range effects in this theory. The Se⁷⁶(d,p)Se⁷⁷ reaction has been studied at 7.8 MeV bombarding energy and eleven angular distributions corresponding to the ground and ten excited states of Se⁷⁷ have been analysed using distorted wave theory. This investigation is described in Chapter 4. Deuteron and proton elastic scattering measurements have also been made from Se⁷⁶ and Se⁷⁷, respectively. The optical model potentials required to describe the stripping distributions are found to be entirely consistent with those derived from the elastic scattering data. In Chapter 5 an account is given of a systematic study of the (t,p) reaction for target nuclei B¹⁰, B¹¹, C¹², C¹⁴, O¹⁸, Si²⁸, Si²⁹ and Ca⁴⁰. This investigation was carried out at triton energies between 8 and 13 MeV. In the majority of cases the angular distributions are observed to be strongly forward peaked and these have been analysed in terms of Newn's plane wave theory of double stripping. With the exception of the B¹⁰(t,p)B¹² and C¹²(t,p)C¹⁴ reactions the agreement in general is found to be very satisfactory. In addition to the ground state, nine excited states of B¹³ were observed and information on the spins and parities of six of them have been obtained. The excitation energies of only four excited states were previously known. C¹⁶ had not previously been observed and the present investigation has shown this to be stable by 4.25 MeV against neutron emission, in good agreement with the predicitons of Zel'dovich. The ground state was confirmed to be O⁺ and the first excited state at 1.753 MeV excitation is probably 2⁺. The delayed neutron emission for C¹⁶ has also been studied and its measured half-life found to be 0.74 ± 0.03 seconds. Angular distributions were measured for the ground and nine excited states of O¹⁸ and ground and four excited states of O²⁰. Only one state, at 4.45 MeV excitation in O¹⁸, could not be interpreted by a double stripping process. Spin-parity assignments from the reactions Si²⁸(t,p)Si³⁰, Si²⁹(t,p)Si³¹ and Ca⁴⁰(t,p)Ca⁴² are in good agreement with earlier measurements. The Be¹¹ nucleus has been studied using the Be⁹(t,p)Be¹¹ reaction at 6 and 10 MeV triton energies. This investigation is described in Chapter 6. At the higher bombarding energy six energy levels of Be¹¹ were observed and three of these were found to have natural widths in excess of 10 keV. Proton distributions were measured at both energies for the ground and first excited states. Their interpretation in terms of a double-stripping mechanism is complicated by the presence of large backward peaks but the distributions are not inconsistent with the spins of 1/2 ^- and 1/2 ⁺, respectively, predicted by Talmi and Unna. Angular distributions from the C¹²(t,α)B¹¹ reaction at 10 MeV triton energy were also studied in an attempt to obtain information on the spins and parities of some of the states in B¹¹ which are involved in the beta-decay of Be¹¹. In Chapter 7 an account is given of triton elastic scattering measurements made at incident energies 6.4, 6.8 and 7.2 MeV from C¹², O¹⁶, O¹⁸, F¹⁹ and Ca⁴⁰. Only the scattering from F¹⁹ and Ca⁴⁰ can be described by the optical model, although the optical parameters are ambiguous. The scattering distributions from O¹⁶ at all three energies exhibit large backward peaks suggestive of compound resonance scattering. Optical model parameters derived from the triton scattering data have been uesd by Rook and Mitra to analyse the proton distributions from Ca⁴⁰(t,p)Ca⁴², using distorted wave theory. A brief account of the results is given in Appendix C.