A grande maioria das infecções causadas em ambientes médicos-odontológicas é proveniente de contaminações cruzadas, quando se tem contato entre diferentes instrumentos e /ou aparelhos contaminados após procedimentos médicos. Atualmente o padrão aceito e amplamente utilizado para esterilização de instrumental são os equipamentos chamados de autoclaves, em que é reconhecido e aceito pelos órgãos legisladores. Porém alguns tipos de instrumental e material não podem ser esterilizados utilizando este método tendo uma outra vertente que é aplicação de agentes químicos. Esses criam problemas socioambientais relacionados a sua utilização e descarte. Dessa forma, o objetivo deste trabalho foi desenvolver uma autoclave multifuncional com a utilização de gás ozônio, ultravioleta e calor úmido, em que se testou e analisou microbiológica os protocolos de esterilização, obtendo entendimento e otimização do mesmo. Os resultados mostraram-nos que a configuração desenvolvida atingiu aspectos de esterilidade nos protocolos de esterilização avaliados. Entretanto tem a necessidade de aprofundar estudos aplicando o baixo vácuo para o entendimento quanto a utilização quanto os protocolos do funcionamento e uma futura otimização para produção em larga escala. / Most of infection in the medical-dental office is prevenient of cross-contamination, when have the contact with different instrumental and materials without basic control after the process and contact on patient. This point have the standard protocol was accept and described in literature, its utilizing for instrumental sterilizing is the autoclave, it is recognized by organs legislators. However, some instrumental and materials not be accept in this method, on this is necessary one method second in this case is chemical on the instrumentation, but created environmental problem in relation its application. Therefore, this research made the proof of conception in the multifunctional autoclave with the option ozone, ultraviolet and moist heat, what it is analyzing the microbiological protocols of the sterilizing, understanding and optimization the sterilizing process. This results show us which this constructive configuration in this work reached aspects of the sterilizing in the protocols, describe in this text. In the future research in this subject could be study the strongly aspects about the vacuum process before the sterilizing process with ozone gas and development and optimization the prototype for make the scaling up.

Este estudo analisou a ação do ozônio como coadjuvante à terapia endodôntica. Assim, (I) avaliou da eficiência da água ozonizada na redução microbiana realizada sobre suspensão bacteriana de Enterococcus faecalis, Pseudomonas aeruginosa e Staphylococcus aureus estudo in vitro; (II) testou a eficiência da água ozonizada e o gás ozônio na redução microbiana realizada em canais radiculares contaminados estudo ex vivo; e, (III) avaliou a reação biológica de cultura de fibroblastos sob aplicação do ozônio pelo método MTT. Inicialmente a água ozonizada nas concentrações de 5, 20 e 40 g/mL foi aplicada diretamente sobre as suspensões bacterianas separadamente por um minuto. Em seguida, foram feitas diluições seriadas e o plaqueamento para posterior contagem das UFC/mL. Na segunda parte, 180 dentes foram inoculados com 10 L das suspensões bacterianas separadamente e incubados por 7 dias. Em seguida foram submetidos aos grupos experimentais: Grupo I: controle de contaminação; Grupo II: instrumentação rotatória associando o hipoclorito de sódio 1% ao Endo-PTC gel e irrigação final com EDTA-T; Grupo III: protocolo semelhante ao Grupo II com a aplicação final do gás ozônio na concentração de 40 g/mL; e, Grupo IV: protocolo semelhante ao Grupo II com a irrigação final com a água ozonizada na concentração de 40 g/mL. Na sequencia de cada grupo foi feita coleta microbiológica, diluição seriada e plaqueamento por 24 horas e contagem das UFC/mL. Na terceira parte, a análise da viabilidade celular dos fibroblastos. O PBS foi ozonizado nas concentrações de 10, 20 e 40 g/mL e aplicado sobre as células. Os dados foram tabulados e submetidos à análise estatística pelo método de Kruskal-Wallis, complementado pelo método de Dunn (p<0.05). A primeira parte do estudo mostrou que o E. faecalis apresentou crescimento nas concentrações de 5 e 20 g/mL. Na análise da P. aeruginosa e o S. aureus não foi possível detectar UFC/mL. Já no estudo ex vivo, o Grupo IV foi o mais efetivo contra os microrganismos testados, com diferença estatística para os demais grupos, quando dos dentes contaminados com a P. aeruginosa. O estudo da viabilidade mostrou que o ozônio, em 0 horas, ocasionou uma queda na viabilidade celular que foi revertida nos demais tempos experimentais. A concentração de 40 g/mL foi a que proporcionou maior estímulo ao final da avaliação, com diferença estatística significante ao Grupo Controle. Diante das metodologias aplicadas, pode-se concluir que (I) a concentração de 40 g/mL foi a mais efetiva para reduzir o número dos microrganismos testados; (II) o protocolo instituído para a fase de preparo químico cirúrgico que associou a terapia tradicional com a água ozonizada na concentração de 40 g/mL foi o mais efetivo; (III) o ozônio em contato com os fibroblastos de gengiva, inicialmente causou diminuição na viabilidade celular, que foi revertida nos tempos experimentais subsequentes. A concentração de 40 g/mL foi a que causou maior redução no número de células viáveis, porém foi a que proporcionou maior estímulo ao final do experimento, mostrando-se biocompatível com a linhagem celular testada; e, (IV) diante do conjunto dos dados experimentais, a água ozonizada na concentração de 40 g/mL, comparada com as demais concentrações testadas, é a que apresenta melhor desempenho quanto ao seu poder antimicrobiano e biocompatibilidade, justificando sua inserção no arsenal clínico na terapia endodôntica. / This study analyzed the action of ozone as an adjunct to endodontic therapy. So (I) evaluated the effectiveness of ozonated water in microbial reducing performed on bacterial suspension of Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus - in vitro study (II) tested the efficiency of ozone gas and ozonated water in reducing microbial held in contaminated root canals - ex vivo study, and (III) evaluated the biological response of fibroblasts culture in the application of ozone, according to MTT method. In the first part of the experiment the ozonated water at concentrations of 5, 20 and 40 g/mL was placed in direct contact with the bacterial suspensions separately for one minute. Then, serial dilutions were made for plating and subsequent counting of CFU/mL. In the second part, 180 teeth were inoculated with 10 L of bacterial suspensions and incubated separately for 7 days. They were then subjected to experimental groups: Group I: contamination control, Group II: rotary instrumentation combining 1%sodium hypochlorite and gel Endo-PTC, final irrigation with EDTA-T, Group III: similar protocol to Group II with final application of ozone gas in concentration of 40 g/mL, and Group IV: protocol similar to Group II with a final irrigation with ozonated water at concentration of 40 g/mL. Following each group was done microbiological collecting and serial dilution and plating for 24 hours and subsequent counting of CFU/mL. In the third part, the analysis of cell viability of gingival fibroblasts was performed by MTT method. The PBS has been ozonized at concentrations of 10, 20 and 40 g/mL and applied on the cells. Data were tabulated and analyzed statistically by Kruskal-Wallis method, complemented by Dunn\'s method (p <0.05). The first part of the study showed that E.faecalis grew in concentrations of 5 and 20 g/mL. The P. aeruginosa and S. aureus were susceptible to all three concentrations of ozonated water, it was not possible to detect CFU/mL. In the second part of the study, the Group IV was the most effective against the tested microorganisms, with statistical difference for the other groups, especially when the teeth were infected with P. aeruginosa. Finally, the third part of the study showed that ozone, at 0 hours, caused a decrease in cell viability that was reversed in the other experimental times. The concentration of 40 g/mL provided the greatest stimulus on the final evaluation period, with statistically significant difference to the control group. Given the methodologies applied, it can be concluded that (I) the concentration of 40 g/mL was most effective at reducing the number of microorganisms, (II) the protocol established for the standard chemical preparation stage associated with ozonated water at a concentration of 40 g/mL was the most effective, (III) the ozone in contact with the gingival fibroblasts, initially caused a decrease in cell viability, which was reversed in subsequent experimental times. The concentration of 40 g/mL was the one that caused a greater reduction in the number of viable cells, however, was that provided the greatest stimulus to the end of the experiment and proved to be biocompatible with the cell line tested, and (IV) on the set of experimental data, the ozonated water at a concentration of 40 g/mL , compared with the other concentrations tested, it has the best performance in terms of its biocompatibility and antimicrobial power, justifying their inclusion in the clinical arsenal in endodontic therapy.

O objetivo desta pesquisa foi o de estudar o desempenho de pós-filtros adsorvedores de carvão ativado granular de origem mineral e de origem vegetal, com relação a, principalmente, remoção de 2-metilisoborneol e trans-1,10-dimetiltrans- 9-decalol. Os ensaios experimentais foram conduzidos na estação de tratamento de água Alto da Boa Vista, empregando-se quatro filtros piloto em acrílico com diâmetro interno de 14,2 cm e 1,5 m de profundidade de meio filtrante cada, sendo dois deles preenchidos com o carvão ativado granular Filtrasorb 300 da CALGON (filtros 1 e 3) e os outros dois, com o carvão ativado granular 119 12x25 da CARBOMAFRA (filtros 2 e 4). Os filtros operaram em paralelo, 24 h por dia, 7 dias por semana, sendo o 3 e 4 abastecidos com água filtrada da estação; e o 1 e 2, com água filtrada ozonizada. A taxa média de aplicação nos filtros durante os ensaios foi de 143 m3m2.d, o que gerou um tempo de contato no leito vazio médio de 15 min. O tempo médio total de detenção nas colunas de ozonização ficou em 21 min e a dosagem média total de ozônio aplicada na água filtrada da estação em 1,11 mgL. Os valores de 2-metilisoborneol na água filtrada da estação de tratamento foram superiores aos da água ozonizada, indicando que a ozonização contribuiu para a redução (média de 53,4 %) deste composto. O filtro que apresentou os menores valores de 2-metilisoborneol foi o do carvão betuminoso, alimentado com água ozonizada (filtro 1), com uma remoção média de 50,6 %. Além disso, foi o único filtro que apresentou valores médios de 2-metilisoborneol abaixo da concentração limiar de odor ( 9,0 ngL). O filtro que apresentou os maiores valores de 2-metilisoborneol foi o 4 (carvão vegetal alimentado com água filtrada da estação). / The main purpose of this research was to study the performance of granular activated carbon post filter adsorbers made of bituminous coal and vegetal coal (coconut), regarding, mainly, removal of 2-methylisoborneol and trans-1,10-dimethyltrans- 9-decalol. The experimental researches were conducted in the water treatment plant Alto da Boa Vista, using four pilot filters, made in acrylic, with an internal diameter of 14.2 cm and a filter media depth of 1.5 m, each. Two of them (named 1 and 3) were filled with the carbon Filtrasorb 300 (CALGON) and the other two (named 2 and 4), with the carbon 119 12x25 (CARBOMAFRA). The filters operated in parallel, 24 h per day, 7 days per week. The filters 3 and 4 were fed with filtered water from the plant and the filters 1 and 2, with filtered plus ozonated water. The average hydraulic loading rate in the filters was 143 m3m2.d and the empty bed contact time, 15 min. The average detention time in the ozone contact columns was 21 min and the average ozone dosage, 1.11 mgL. The 2-methylisoborneol values in the filtered water of the plant were higher than in the ozonated water, which indicates that the ozonation reduced (average of 53.4 %) this substance. The filter that showed the lower values of 2-methylisoborneol was the bituminous one, fed with ozonated water (filter 1), with an average removal of 50.6 %. Moreover, was the only one that presented average values of 2-methylisoborneol lower than the odor threshold concentration ( 9,0 ngL). The filter that presented the higher values of 2- methylisoborneol was the vegetal one, fed with filtered water (filter 4).

Com o intuito de viabilizar, ambiental e economicamente, a degradação de algumas substâncias perigosas e recalcitrantes, presentes em águas e efluentes, foi desenvolvido um sistema para estudar a tratabilidade dessas substâncias, utilizando Processos Oxidativos Avançados POAs. As espécies escolhidas foram o fenol (C6H5OH) a 50 mg L-1 e o cianeto de potássio (KCN) a 20 mg L-1. Os resíduos químicos foram submetidos a tratamentos com diferentes doses de O3 (0, 2,4 e 4,8 g h-1), H2O2 (0, 150 e 300 mg L-1 para o fenol e 0, 60 e 120 mg L-1 para o cianeto) e UV (0, 8 e 32 watts), pois tais combinações promovem a geração de radicais hidroxila (OH), cujo potencial de oxidação é superior ao de cada oxidante individualmente. O sistema desenvolvido funciona em batelada com recirculação, possibilitando todas as combinações de interesse entre os oxidantes, com capacidade máxima de 300 mL de resíduo, volume adotado para todos os testes deste trabalho. O sistema é composto por uma coluna cilíndrica disposta na posição vertical, ligada a um reator UV. Outros equipamentos instalados são a bomba para a circulação do resíduo, o concentrador de O2, o ozonizador (0-24 g h-1), cujo gás é insuflado pela base da coluna, e seu excesso passa pelo destruidor de O3, composto por uma coluna preenchida com carvão ativado. A solução de H2O2 é adicionada ao sistema com o auxílio de uma seringa. A eficiência do processo de mineralização do fenol, foi avaliada através de 27 tratamentos (combinações) nos tempos de 15 e 30 minutos e pH 6,5. As amostras coletadas foram analisadas em equipamento Shimadzu TOC-5000A, obtendo-se a concentração de carbono orgânico total. Os dados foram submetidos à análise estatística (Fatorial e teste de Tukey, p<0,05). As combinações com os melhores resultados foram utilizadas para uma segunda etapa de testes, variando os tempos em 5, 15, 30 e 45 minutos. Os novos dados foram submetidos à análise estatística e, novamente, as combinações com melhores resultados foram utilizadas para avaliação do efeito do pH (6,5 e 9,5) na mineralização do fenol. A combinação O3 (4,8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1), em pH 9,5, apresentou a melhor condição de tratamento em 30 minutos, proporcionando 99,7% de mineralização do fenol. O delineamento experimental do cianeto foi baseado nas melhores razões oxidante/resíduo obtidas para o fenol. Foi preparada solução 8,13 mg L-1 de CN previamente alcalinizada (pH 11,0). Os tempos estudados foram 1, 2, 4, 5 e 10 minutos e as amostras foram submetidas à análise de N-NO3 por espectrofotometria em sistema por análise em fluxo. Neste caso a combinação O3 (4,8 g h-1) / UV (32 watts), proporcionou 97,6% da oxidação do cianeto à NO3 em 7 minutos de tratamento. Os custos dos tratamentos nas melhores condições foram de R$ 11,08 por litro de fenol tratado e R$ 4,20 por litro de cianeto tratado. Concluiu-se que o sistema proposto foi eficiente no tratamento de ambos resíduos químicos (fenol e cianeto) em um curto período de tempo / In order to facilitate, environmentally and economically, the degradation of some hazardous and recalcitrant substances, presented in waters and wastewaters, a system was developed to study the treatability of chemical substances using Advanced Oxidative Processes AOPs. The substances chosen were phenol (C6H5OH) at 50 mg L-1 and potassium cyanide (KCN) at 20 mg L-1. The chemical residues were submitted to treatments with different combinations and doses of O3 (0, 2.4, and 4.8 g h-1), H2O2 (0, 150 and 300 mg L-1 for phenol and 0, 60 and 120 mg L-1 for cyanide) and ultraviolet radiation (0, 8 and 32 watts), as these combinations promote the generation of hydroxyl radicals (OH), whose oxidation potential is greater than of each oxidant individually. The developed system works in batch treatments with recirculation, allowing all combinations of interests among the oxidants, with a maximum capacity of 300 mL of waste, adopted for all tests of this work. The system consists of a cylindrical column disposed in the vertical position and connected to a UV reactor. Other installed equipments are the pump for residual recirculation, the O2 concentrator, the ozonator (0-24 g h-1), which gas is blown from the base of the column and its excess is destroyed by the equipment composed of a glass column filled with granulate activated carbon. The solution of H2O2 is added to the system with the aid of a syringe. The efficiency of the mineralization of phenol was evaluated in 27 treatments in 15 and 30 minutes and pH 6.5. The collected samples were analyzed in Shimadzu TOC 5000A equipment, obtaining the concentration of total organic carbon (TOC). The obtained data were submitted to statistical analysis (Factorial and Tukey test, p<0.05). The combinations with the best results were used for a second phase of tests, varying the time at 5, 15, 30, and 45 minutes. The new data were submitted to statistical analysis and the best performing combinations were used to evaluate the effect of pH (6.5 and 9.5) in the mineralization of phenol. The combination of O3 (4.8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1) at pH 9.5 showed the best treatment condition in 30 minutes, providing 99.7% of phenol mineralization. The experimental design of cyanide was based on the best oxidant/residue reasons obtained for phenol. A solution with 8.13 mg L-1 of CN previously alkaline (pH 11.0) was prepared. The treatment times were 1, 2, 4, 5 and 10 minutes and the samples were submitted to N-NO3 analysis by spectrophotometry system in flow injection analysis. In this case the combination O3 (4.8 g h-1) / UV (32 watts) provided 97.6 % of oxidation of the cyanide to NO3 in 7 minutes of treatment. The costs of treatments in the best conditions were R$ 11,08 per litter of phenol treated and R$ 4,20 per litter of cyanide treated. It can be concluded that the proposed system was effective in the treatment of both chemical residues (phenol and cyanide) in a short period of time

Atmospheric concentrations of surface ozone (O3) are strongly affected by deposition to the biosphere. Deposition processes are very sensitive to turbulence, temperature, relative humidity and soil moisture deficit and are expected to respond to global climate change, with implications for both air quality (e.g. human health) and ecosystem services (e.g. crop yields). In this PhD study, the global chemistry aerosol model UKCA (United Kingdom Chemistry Aerosol model) dry deposition scheme was thoroughly investigated. Some errors in the existing implementation of the current UKCA stomatal resistance and in-canopy aerodynamic resistance terms for O3 and NOw (NO2, PAN, PPAN, MPAN) were identified and corrected (WES scheme). These model corrections led to a decrease of the total annual dry deposition of -150 Tg(O3) yr-1 (-13%) which brings UKCA more in line with multi-model inter-comparison estimates. This was associated with a large increase of surface O3 concentration over land in the Northern Hemisphere (NH) with values up to 12 ppb (+50%) higher on annual average. Many studies have shown that O3 stomatal uptake by vegetation, which is the pathway leading to damage, accounts for 40-60% of total deposition on average. The remaining non-stomatal deposition flux is to external foliar surfaces, and soil. A more mechanistic non-stomatal dry deposition approach along with a scheme to simulate the effect of moisture on foliar surfaces on the stomatal transport (ZHG scheme) was introduced in UKCA to study the relative contributions of O3 flux occurring to stomatal and non-stomatal pathways at the global scale, and to explore the sensitivity of simulated surface O3 and O3 deposition flux. The ZHG scheme, led to significant changes in the O3 dry deposition velocity (Vd) (+40% in the North Hemisphere over boreal forests and -30% over tropical regions on annual average). The results of this study show that the ZHG scheme significantly changes the partitioning between stomatal and non-stomatal O3 flux. The non-stomatal fraction increased throughout the year and considerably during the cooler season and in spring (with maxima values by up to 60% for C3 grass and by up to 70% for needle leaf trees). The performance of both UKCA dry deposition schemes were compared with measurements, focussing on the diurnal and seasonal variations of the dry deposition velocity terms and the partitioning of O3 fluxes between stomatal and non-stomatal sinks. Overall, both UKCA dry deposition schemes capture the diurnal variations of Vd reasonably well. However, this study highlighted difficulties in comparing large grid (~280 x 390 km at mid-latitudes) averaged modelled values with site and vegetation specific characteristics of the measured exchange processes (~1 km2) and the driving meteorological variables. These differences in scale are a large source of uncertainty in the comparison of measured and modelled O3 Vd. Off-line simulation tests conducted on the non-stomatal deposition component with the ZHG scheme demonstrated the importance of modelling some key environmental and meteorological factors accurately (e.g. relative humidity, friction velocity, leaf area index). This was found to be crucial in order to improve O3 Vd model performance as well as improving the representation of specific vegetation properties. A comparison of the modelled global surface O3 concentration against observations both in the NH and SH revealed that the model performs well in the NH using both schemes, capturing the observed surface O3 cycle and the absolute values. The ZHG scheme led to a reduction of the annual bias (up to -13.5% on average) in the NH monitoring sites considered for this study. This is associated with a decrease in O3 deposition simulated with ZHG (as much as of -20% on annual average). By contrast, the seasonal cycle and absolute values of the observed surface O3 are not well reproduced by the model across the SH monitoring sites used in this study and a larger bias was found using the ZHG scheme (60% on average) compared to WES scheme (47% on average), as a consequence of an increase in O3 deposition (as much as of +20% on annual average) calculated with ZHG. A future climate integration for the 2090s using RCP 8.5 scenario was used to investigate the response of UKCA modelled O3 to climate change. The effect of climate change (by altering only the GHG concentrations predicted with RCP 8.5) on the dry deposition sink of O3 was addressed contrasting the two non-stomatal deposition parameterizations, and ignoring the changes in land-use and anthropogenic emissions. The study showed that O3 Vd over land declines from 2000 to 2100, and most strongly over vegetated areas (up to -24% over S. America, -17% over N. America and -10% over Europe). Climate change led to an increase of surface O3 concentration over land (by up to 20%). Whilst the two schemes behave similarly, and an increase in turbulence has been identified as the main driver, the decrease in land Vd is generally stronger in ZHG. This effect is more important over N. America and Eurasia where ZHG exhibits larger differences in deposition compared to WES as a result of changing climate. The increase in surface O3 over Arctic and Antarctic regions shows the effect that changes in O3 deposition might have on the long-range transport of O3. Finally, the influence of climate change on the partitioning of the O3 deposition flux was examined. This analysis revealed that more O3 is predicted to deposit through stomatal pathways with ZHG over N. America, C. Europe and E. Asia (up to +30%) compared to WES as a result of changing climate. Given that ZHG scheme captures the influence of meteorology and changing climate on surface O3 better than WES, it was concluded that modelled surface O3 using ZHG scheme showed a larger sensitivity to a changing climate than WES. These results imply potentially important effects of climate change on tropospheric O3, degrading air quality through the later decades of this century.

O objetivo principal desta pesquisa foi desenvolver um aparato e procedimento experimental para estudar a oxidação química de organoclorados por injeção de ozônio em escala de laboratório. A concepção do ensaio desenvolvido permite realizar ensaios de coluna em meio aquoso ou em meio poroso, saturado ou não saturado, com monitoramento da concentração e da pressão absoluta de ozônio na entrada e na saída da coluna, do pH, da temperatura do meio, da temperatura ambiente e controle da vazão. Nesta pesquisa foram realizados ensaios para verificar a degradação de PCE em fase dissolvida em concentração de saturação em diversos meios: água ultrapura, águas subterrâneas coletadas em um poço cacimba e em um poço tubular profundo, e soluções de bicarbonato de sódio. A investigação experimental compreendeu ensaios de saturação e decaimento de ozônio, ensaios batch e ensaios de coluna em meios com valores de pH variados. Os resultados indicaram que o ozônio em fase dissolvida atinge a saturação após aproximadamente 15 minutos de injeção, com concentrações saturadas variando entre 90 e 170 µmol/L, dependendo do meio aquoso de estudo. O decaimento biexponencial do ozônio dissolvido mostrou tempos de meia vida t1 e t2, que variaram conforme o meio de estudo, entre 4 e 26 minutos, e 14 e 193 minutos, respectivamente. O decaimento monoexponencial resultou em tempos de meia vida entre 12 e 76 minutos. Os ensaios batch em meio aquoso mostraram degradação significativa do PCE por ozônio dissolvido comparativamente à degradação em água ultrapura não ozonizada. A adição de bicarbonato de sódio diminuiu os tempos de meia vida do ozônio em água, mas não intensificou a degradação do PCE em sistema fechado (ensaios batch). Os ensaios de coluna em meio aquoso indicaram que a volatilização e o arraste são os principais mecanismos de remoção de PCE por injeção de ozônio. As concentrações de PCE em fase dissolvida observadas no início do ensaio de coluna foram quase completamente volatilizadas e recuperadas no trap, tanto nos ensaios com a injeção de oxigênio quanto nos ensaios com injeção de ozônio. As concentrações de PCE na coluna no final dos ensaios foram inferiores ou ligeiramente superiores ao valor de intervenção estabelecido pela CETESB em 2014. Os ensaios de coluna em meio sólido (microesferas de vidro e areia) indicaram que ocorre degradação do PCE, com remoção quase total na coluna, porém com menor recuperação no trap. Possivelmente, o maior tempo de residência na coluna favorece as reações do ozônio com o PCE. / The aim of this research was to develop experimental apparatus and procedure to investigate chemical oxidation of chlorinated organic compounds by ozone injection at laboratory scale, in aqueous media and in saturated or unsaturated porous media. The test allows control of ozone inlet and outlet pressures and concentrations, pH, room and column temperature, and ozone flow. In this research, tests were performed to investigate degradation of PCE dissolved at maximum solubility concentration in several media: ultrapure water, groundwater collected in a shallow well and in a deep well, and sodium bicarbonate solutions. The experimental investigation comprised ozone saturation and decay tests, batch tests, and column tests in aqueous media with several pH values. Results indicated that dissolved ozone reaches saturation after approximately 15 minutes of injection, at saturated concentrations between 90 and 170 µmol/L, depending on the aqueous medium. Second order ozone decay half lives t1 and t2 vary, respectively, between 4-26 minutes and 14-193 minutes depending on the aqueous medium. First order decay half lives varied between 12-76 minutes. Batch tests in aqueous media showed significant PCE degradation by dissolved ozone as compared to degradation in non ozonized ultrapure water. Addiction of sodium bicarbonate decreased ozone half-lives in water but did not intensify PCE degradation as observed in the results of batch tests. Column tests in aqueous media evinced that stripping and volatilization are the mains mechanisms of PCE removal by ozone injection. Initial concentrations of dissolved PCE in the column were almost completely volatilized and recovered in the trap, for ozone injection as well as for oxygen injection. Final concentrations of dissolved PCE in the column were in the order of ppb and very near the limit allowable value according to the environmental agency of the state of São Paulo. Column tests in solid media indicate that PCE degrades and is removed from the column, but not totally recovered in the trap; probably, the more extended residence time in the column enhances reactions of ozone and PCE

Ozone dry deposition, an important tropospheric ozone sink, is expected to evolve with climate and land use, but coarse representation of ozone dry deposition in most large-scale atmospheric chemistry models hinders understanding of the influence of this sink on ozone air quality. Ozone uptake by stomata, injurious to plants, has been emphasized in the atmospheric chemistry community as the predominant terrestrial ozone depositional sink. However, there is an abundance of observational evidence from monitoring sites around the world suggesting that nonstomatal deposition processes (e.g., surface-mediated aqueous reactions on leaf cuticles, reactions with soil organic matter) are important ozone sinks. With observations from one of the longest ozone eddy covariance datasets available and a model hierarchy, I find substantial variations in nonstomatal ozone dry deposition, which is a non-negligible amount of the total ozone dry deposition, and identify the individual deposition processes driving observed variability. I pinpoint the responses of ozone pollution to changes in precursor emissions, climate, and ozone dry deposition at the beginning and end of the 21st century using a new version of the NOAA GFDL chemistry-climate model that more explicitly resolves deposition processes by leveraging the interactive biophysics of the land component of the model. My work highlights that under strong precursor emission controls there is a shift in the high ozone pollution season over northern mid-latitudes to a wintertime peak, and that wintertime ozone is sensitive to ozone dry deposition due to the long ozone lifetime. For both summer and winter, I find that neglecting variations in nonstomatal deposition and dependencies on environmental conditions may hinder accurate identification of the processes driving observed trends and variability in ozone pollution. In light of the sensitivity of ozone to dry deposition during winter, I identify a need for developing observational constraints on the wintertime depositional sink.

Com o intuito de viabilizar, ambiental e economicamente, a degradação de algumas substâncias perigosas e recalcitrantes, presentes em águas e efluentes, foi desenvolvido um sistema para estudar a tratabilidade dessas substâncias, utilizando Processos Oxidativos Avançados POAs. As espécies escolhidas foram o fenol (C6H5OH) a 50 mg L-1 e o cianeto de potássio (KCN) a 20 mg L-1. Os resíduos químicos foram submetidos a tratamentos com diferentes doses de O3 (0, 2,4 e 4,8 g h-1), H2O2 (0, 150 e 300 mg L-1 para o fenol e 0, 60 e 120 mg L-1 para o cianeto) e UV (0, 8 e 32 watts), pois tais combinações promovem a geração de radicais hidroxila (OH), cujo potencial de oxidação é superior ao de cada oxidante individualmente. O sistema desenvolvido funciona em batelada com recirculação, possibilitando todas as combinações de interesse entre os oxidantes, com capacidade máxima de 300 mL de resíduo, volume adotado para todos os testes deste trabalho. O sistema é composto por uma coluna cilíndrica disposta na posição vertical, ligada a um reator UV. Outros equipamentos instalados são a bomba para a circulação do resíduo, o concentrador de O2, o ozonizador (0-24 g h-1), cujo gás é insuflado pela base da coluna, e seu excesso passa pelo destruidor de O3, composto por uma coluna preenchida com carvão ativado. A solução de H2O2 é adicionada ao sistema com o auxílio de uma seringa. A eficiência do processo de mineralização do fenol, foi avaliada através de 27 tratamentos (combinações) nos tempos de 15 e 30 minutos e pH 6,5. As amostras coletadas foram analisadas em equipamento Shimadzu TOC-5000A, obtendo-se a concentração de carbono orgânico total. Os dados foram submetidos à análise estatística (Fatorial e teste de Tukey, p<0,05). As combinações com os melhores resultados foram utilizadas para uma segunda etapa de testes, variando os tempos em 5, 15, 30 e 45 minutos. Os novos dados foram submetidos à análise estatística e, novamente, as combinações com melhores resultados foram utilizadas para avaliação do efeito do pH (6,5 e 9,5) na mineralização do fenol. A combinação O3 (4,8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1), em pH 9,5, apresentou a melhor condição de tratamento em 30 minutos, proporcionando 99,7% de mineralização do fenol. O delineamento experimental do cianeto foi baseado nas melhores razões oxidante/resíduo obtidas para o fenol. Foi preparada solução 8,13 mg L-1 de CN previamente alcalinizada (pH 11,0). Os tempos estudados foram 1, 2, 4, 5 e 10 minutos e as amostras foram submetidas à análise de N-NO3 por espectrofotometria em sistema por análise em fluxo. Neste caso a combinação O3 (4,8 g h-1) / UV (32 watts), proporcionou 97,6% da oxidação do cianeto à NO3 em 7 minutos de tratamento. Os custos dos tratamentos nas melhores condições foram de R$ 11,08 por litro de fenol tratado e R$ 4,20 por litro de cianeto tratado. Concluiu-se que o sistema proposto foi eficiente no tratamento de ambos resíduos químicos (fenol e cianeto) em um curto período de tempo / In order to facilitate, environmentally and economically, the degradation of some hazardous and recalcitrant substances, presented in waters and wastewaters, a system was developed to study the treatability of chemical substances using Advanced Oxidative Processes AOPs. The substances chosen were phenol (C6H5OH) at 50 mg L-1 and potassium cyanide (KCN) at 20 mg L-1. The chemical residues were submitted to treatments with different combinations and doses of O3 (0, 2.4, and 4.8 g h-1), H2O2 (0, 150 and 300 mg L-1 for phenol and 0, 60 and 120 mg L-1 for cyanide) and ultraviolet radiation (0, 8 and 32 watts), as these combinations promote the generation of hydroxyl radicals (OH), whose oxidation potential is greater than of each oxidant individually. The developed system works in batch treatments with recirculation, allowing all combinations of interests among the oxidants, with a maximum capacity of 300 mL of waste, adopted for all tests of this work. The system consists of a cylindrical column disposed in the vertical position and connected to a UV reactor. Other installed equipments are the pump for residual recirculation, the O2 concentrator, the ozonator (0-24 g h-1), which gas is blown from the base of the column and its excess is destroyed by the equipment composed of a glass column filled with granulate activated carbon. The solution of H2O2 is added to the system with the aid of a syringe. The efficiency of the mineralization of phenol was evaluated in 27 treatments in 15 and 30 minutes and pH 6.5. The collected samples were analyzed in Shimadzu TOC 5000A equipment, obtaining the concentration of total organic carbon (TOC). The obtained data were submitted to statistical analysis (Factorial and Tukey test, p<0.05). The combinations with the best results were used for a second phase of tests, varying the time at 5, 15, 30, and 45 minutes. The new data were submitted to statistical analysis and the best performing combinations were used to evaluate the effect of pH (6.5 and 9.5) in the mineralization of phenol. The combination of O3 (4.8 g h-1) / UV (32 watts) / H2O2 (300 mg L-1) at pH 9.5 showed the best treatment condition in 30 minutes, providing 99.7% of phenol mineralization. The experimental design of cyanide was based on the best oxidant/residue reasons obtained for phenol. A solution with 8.13 mg L-1 of CN previously alkaline (pH 11.0) was prepared. The treatment times were 1, 2, 4, 5 and 10 minutes and the samples were submitted to N-NO3 analysis by spectrophotometry system in flow injection analysis. In this case the combination O3 (4.8 g h-1) / UV (32 watts) provided 97.6 % of oxidation of the cyanide to NO3 in 7 minutes of treatment. The costs of treatments in the best conditions were R$ 11,08 per litter of phenol treated and R$ 4,20 per litter of cyanide treated. It can be concluded that the proposed system was effective in the treatment of both chemical residues (phenol and cyanide) in a short period of time

During 2004 and 2006 the University of Iowa provided air quality forecast support for flight planning of the ICARTT and MILAGRO field campaigns. A method for improvement of model performance in comparison to observations is showed. The method allows identifying sources of model error from boundary conditions and emissions inventories. Simultaneous analysis of horizontal interpolation of model error and error covariance showed that error in ozone modeling is highly correlated to the error of its precursors, and that there is geographical correlation also. During ICARTT ozone modeling error was improved by updating from the National Emissions Inventory from 1999 and 2001, and furthermore by updating large point source emissions from continuous monitoring data. Further improvements were achieved by reducing area emissions of NOx y 60% for states in the Southeast United States. Ozone error was highly correlated to NOy error during this campaign. Also ozone production in the United States was most sensitive to NOx emissions. During MILAGRO model performance in terms of correlation coefficients was higher, but model error in ozone modeling was high due overestimation of NOx and VOC emissions in Mexico City during forecasting. Large model improvements were shown by decreasing NOx emissions in Mexico City by 50% and VOC by 60%. Recurring ozone error is spatially correlated to CO and NOy error. Sensitivity studies show that Mexico City aerosol can reduce regional photolysis rates by 40% and ozone formation by 5-10%. Mexico City emissions can enhance NOy and O3 concentrations over the Gulf of Mexico in up to 10-20%. Mexico City emissions can convert regional ozone production regimes from VOC to NOx limited. A method of interpolation of observations along flight tracks is shown, which can be used to infer on the direction of outflow plumes. The use of ratios such as O3/NOy and NOx/NOy can be used to provide information on chemical characteristics of the plume, such as age, and ozone production regime. Interpolated MTBE observations can be used as a tracer of urban mobile source emissions. Finally procedures for estimating and gridding emissions inventories in Brazil and Mexico are presented.

The goal of this thesis is to investigate the kinetics and amount of SO2 uptake on hematite, which will act as a representative of mineral dust aerosol. The environmental reaction chamber used here will allow the variation of water vapor pressure to examine the effect of relative humidity (RH) on these parameters. The role of a common atmospheric oxidant, ozone, in the uptake process will also be investigated. The results will be presented with emphasis on the role of hematite in mineral dust aerosols as a sink of SO2, and the possible acidification of hematite particles through heterogeneous reaction pathways.