Degradação de espécies químicas de relevância ambiental utilizando-se processo oxidativos avançados

Orientador: Patricio Peralta ZamoraAs páginas 66, 68 e 97 tem gráficos com linhas apagadas, e por erro de paginação não há página 105.Dissertação (mestrado) - Universidade Federal do ParanáResumo: Neste trabalho realizaram-se estudos tendentes a avaliar o potencial de alguns processos oxidativos avançados (POAs), em relação à capacidade de degradação de substratos químicos de interesse ambiental, especificamente compostos fenólicos. Preliminarmente, os sistemas Ti02-UV, ZnO-UV e H202-UV foram avaliados, utilizando-se uma estratégia multivariada (sistema de planejamento fatorial) que permitiu identificar as condições experimentais ótimas para a degradação de um substrato padrão (fenol, 1x10"3 molL"1). Estas condições estão representadas por pH 4,0 e 25 mg de semicondutor para o sistema Ti02-UV, pH 8,0 e 25 mg de semicondutor para o sistema ZnO-UV e pH 5,5 e relação molar H202/Fenol de 15:1 para o sistema H202-UV. Utilizando-se um reator fotoquímico de irradiação superficial, os principais parâmetros cinéticos do processo de degradação de fenol foram medidos, argumentos estes que revelaram o sistema H202-UV como o de melhor eficiência. Nas condições otimizadas, este sistema permitiu a completa degradação de fenol em tempos de reação da ordem de 15 min. Estudos complementares realizados por cromatografia líquida de alta eficiência permitiram a identificação de alguns intermediários de degradação característicos, dentre os que destacam hidroquinona, benzoquinona, pirogalol e pirocatecol. Com base nestas evidências, uma rota mecanística de degradação foi proposta. Em etapas mais avançadas do estudo, um reator de maior eficiência foi utilizado (sistema de irradiação interna). Neste sistema, estudos de degradação de fenol, clorofenol, efluente de polpação de madeira (licor negro) e efluente de branqueamento de polpa (kraft Ei), foram realizados. Diversos testes analíticos foram aplicados, visando-se caracterizar a verdadeira extensão do processo de degradação dos resíduos. Dentro deste contexto, resultados satisfatórios foram obtidos nos estudos envolvendo fenol (redução de fenóis totais superior a 90% em 15 min de tratamento), ortoclorofenol (resultados similares aos observados para fenol) e licor negro (remoção praticamente completa das espécies fenólicas em tempos de 15 min). Estudos realizados por meio de bio-ensaio demonstraram a significativa e sistemática diminuição da toxicidade aguda durante o decorrer do tratamento estudado. Resultados igualmente positivos não foram obtidos para o efluente de branqueamento Kraft Ei, que demonstrou resistência ao sistema H2O2-UV. Neste caso, a redução de fenóis totais foi de apenas 50%, após 2 horas de tratamento. De igual forma, o bio-ensaio respirométrico demostrou ineficiente remoção da toxicidade aguda associada a este resíduo. Em função dos resultados obtidos, é possível observar que os processos oxidativos avançados aqui estudados representam um elevado potencial de aplicação para o tratamento de resíduos desta natureza químicaAbstract: In this work the potentiality of some advanced oxidative processes (POAs) toward the degradation of chemical species of environmental relevance (phenolic compounds) was investigated. Preliminarily, the Ti02-UV, ZnO-UV and H202-UV systems were evaluated by using a multivariate strategy (factorial design study). By this study, the optimal experimental conditions for degradation of a IxlO"3 moL"1 aqueous phenol solution were established, conditions that are represented by pH 4.0 and 25 mg of semiconductor for the Ti02-UV system, pH 8.0 and 25 mg of semiconductor for the ZnO-UV system, and pH 5.5 and a 15:1 H202:phenol molar ratio for the H202-UV system. Using a superficially-irradiated photochemical reactor the main kinetics parameters of the phenol degradation process were investigated. In these studies, the H202-UV system show the best performance, permitting almost total phenol degradation at reaction times of about 15 min. In complementary studies, some intermediate species were identified by high performance liquid chromatography. The identification of hydroquinone, benzoquinone, pyrogallol and pyrocatechol permitted the proposition of a mechanistic route for the phenol degradation process. In more advanced stages of the work, a photochemical reactor of high photonic yield was used (internal irradiation). With this system, degradation studies involving phenol, chlorophenol, and two effluents from the paper industry (black liquor and bleaching E1 stage) were carried out. Several analytical methodologies were used to characterize the degradation process. Good results were observed in the degradation study of phenol and o-chlorophenol (total phenols reduction higher than 90% at reaction times of 15 min), and black liquor (almost total removal of phenolic species at reaction times of about 15 min. Using a bioassay, the significantly reduction of acute toxicity during the photochemical treatment was demonstrated. Resembling positive results were not observed in the studies involving the bleaching effluent (E1). This sample was resistant to the H2O2-UV process, showing a degradation of about 50 % of the total phenols content at reaction times of 2 h. Similarly, the respirometric bioassay demonstrated inefficiency of the process in the elimination of the acute toxicity associated with this residue. In view of the obtained results it is possible to observe that the advanced oxidative processes studied here present a high application potentiality in the treatment of residues of this chemical nature

Indicadores ambientais de sustentabilidade sistematizados pelo modelo pressão-estado-resposta (PER): análise de águas superficiais na microbacia hidrográfica Passo da Pedra, em Pato Branco – PR.

No presente trabalho foi desenvolvido um estudo direcionado a avaliação da sustentabilidade ambiental da micro bacia Hidrográfica do Rio Passo da Pedra do município de Pato Branco-PR por meio de indicadores de sustentabilidade atrelados ao modelo pressão, estado, resposta (PER). Os procedimentos metodológicos incluíram as etapas de revisão crítica de literatura, diagnóstico ambiental da área de estudo e a seleção/proposição dos parâmetros relacionados. Após serem analisados os fatores de relevância sobre as águas superficiais para gestão ambiental eficiente foram estabelecidos 15 indicadores caracterizados quanto ao nome, definição, importância, mecanismo de medição, unidade de medida, frequência de coleta e enquadramento no modelo PER. Os indicadores ora definidos permitem criar e avaliar programas e políticas públicas que visem reverter o quadro atual, com ações e práticas voltadas à sustentabilidade ambiental nas micro bacias hidrográficas. Adicionalmente seu arranjo pode proporcionar um melhor entendimento das relações estabelecidas entre as pressões antrópicas e o ambiente, os indicadores desenvolvidos neste trabalho permitirão evidenciar as suas inter-relações

Caracterização física, química e ecotoxicológica de efluente da indústria de fabricação de explosivos

The production and use of nitroaromatic explosives have resulted in their dissemination into the environment, where their presence in waterways and soil represents an ecological and health hazard. The hazardous characteristics of these compounds need to be carefully studied, so that the impact of their discharge on the environment can be better evaluated. This work presents the characterization of wastewater from Brazilian TNT industry using as analytical techniques mass spectroscopy, chromatography, toxicity assays and other physico-chemical analyses

CULTIVO DE PLEUROTUS OSTREATUS EM RESIDUOS DA AGROINDUSTRIA DE MILHO

Este trabalho avaliou o potencial do fungo Pleurotus ostreatus para a conversão de resíduos da cadeia do milho oriundos da região Sudoeste do Paraná. A metodologia do trabalho consistiu em estudar através de planejamento fatorial de experimentos completo o efeito dos co-substratos palha de milho e efluente agroindustrial oriundo do processo de produção de farinha de milho, canjica especial e farinha de biju. Os resultados mostraram que a adição do efluente nos níveis de variação estudados reduziu o grau de colonização do formulado pelo fungo. Os melhores resultados, que produziram o maior índice de colonização (93%) foi observada para a condição que utilizou 30% de palha de milho e 30% de efluente agroindustrial

The need for fast-track, high-quality and low-cost studies about the role of the BCG vaccine in the fight against COVID-19.

Bacillus Calmette-Guérin (BCG) vaccination is routine and near-universal in many low- and middle-income countries (LMIC). It has been suggested that BCG can have a protective effect on COVID-19 morbidity and mortality. This commentary discusses the limitations of the evidence around BCG and COVID-19. We argue that higher-quality evidence is necessary to understand the protective effect of the BCG vaccine from existing, secondary data, while we await results from clinical trials currently conducted in different settings

Seroprevalence of Chikungunya Virus after Its Emergence in Brazil.

Chikungunya has had a substantial impact on public health because of the magnitude of its epidemics and its highly debilitating symptoms. We estimated the seroprevalence, proportion of symptomatic cases, and proportion of chronic form of disease after introduction of chikungunya virus (CHIKV) in 2 cities in Brazil. We conducted the population-based study through household interviews and serologic surveys during October-December 2015. In Feira de Santana, we conducted a serologic survey of 385 persons; 57.1% were CHIKV-positive. Among them, 32.7% reported symptoms, and 68.1% contracted chronic chikungunya disease. A similar survey in Riachão do Jacuípe included 446 persons; 45.7% were CHIKV-positive, 41.2% reported symptoms, and 75.0% contracted the chronic form. Our data confirm intense CHIKV transmission during the continuing epidemic. Chronic pain developed in a high proportion of patients. We recommend training health professionals in management of chronic pain, which will improve the quality of life of chikungunya-affected persons

Previous BCG vaccination is associated with less severe clinical progression of COVID-19

Background: BCG vaccination, originally used to prevent tuberculosis, is known to “train” the immune system to improve defence against viral respiratory infections. We investigated whether a previous BCG vaccination is associated with less severe clinical progression of COVID-19./ Methods: A case-control study comparing the proportion with a BCG vaccine scar (indicating previous vaccination) in cases and controls presenting with COVID-19 to health units in Brazil. Cases were subjects with severe COVID-19 (O2 saturation < 90%, severe respiratory effort, severe pneumonia, severe acute respiratory syndrome, sepsis, and septic shock). Controls had COVID-19 not meeting the definition of “severe” above. Unconditional regression was used to estimate vaccine protection against clinical progression to severe disease, with strict control for age, comorbidity, sex, educational level, race/colour, and municipality. Internal matching and conditional regression were used for sensitivity analysis./ Results: BCG was associated with high protection against COVID-19 clinical progression, over 87% (95% CI 74–93%) in subjects aged 60 or less and 35% (95% CI − 44–71%) in older subjects./ Conclusions: This protection may be relevant for public health in settings where COVID-19 vaccine coverage is still low and may have implications for research to identify vaccine candidates for COVID-19 that are broadly protective against mortality from future variants. Further research into the immunomodulatory effects of BCG may inform COVID-19 therapeutic research.

Epidemiological characteristics and temporal trends of new leprosy cases in Brazil: 2006 to 2017.

Our study aims to describe trends in new case detection rate (NCDR) of leprosy in Brazil from 2006 to 2017 overall and in subgroups, and to analyze the evolution of clinical and treatment characteristics of patients, with emphasis on cases diagnosed with grade 2 physical disabilities. We conducted a descriptive study to analyze new cases of leprosy registered in the Brazilian Information System for Notificable Diseases (SINAN), from 2006-2017. We calculated the leprosy NCDR per 100,000 inhabitants (overall and for individuals aged < 15 and ≥ 15 years) by sex, age, race/ethnicity, urban/rural areas, and Brazilian regions, and estimated the trends using the Mann-Kendall non-parametric test. We analyzed the distributions of cases according to relevant clinical characteristics over time. In Brazil, there was a sharp decrease in the overall NCDR from 23.4/100,000 in 2006 to 10.3/100,000 in 2017; among children < 15 years, from 6.94 to 3.20/100,000. The decline was consistent in all Brazilian regions and race/ethnicity categories. By 2017, 70.2% of the cases were multibacillary, 30.5% had grade 1 (G1D) or 2 (G2D) physical disabilities at diagnosis and 42.8% were not evaluated at treatment completion/discharge; cases with G2D at diagnosis were mostly detected in urban areas (80%) and 5% of cases died during the treatment (leprosy or other causes). Although the frequency of leprosy NCDR decreased in Brazil from 2006 to 2017 across all evaluated population groups, the large number of cases with multibacillary leprosy, physical disabilities or without adequate evaluation, and among children suggest the need to reinforce timely diagnosis and treatment to control leprosy in Brazil

Seroprevalence of Chikungunya virus and living conditions in Feira de Santana, Bahia-Brazil.

BACKGROUND: Chikungunya is an arbovirus, transmitted by Aedes mosquitoes, which emerged in the Americas in 2013 and spread rapidly to almost every country on this continent. In Brazil, where the first cases were detected in 2014, it currently has reached all regions of this country and more than 900,000 cases were reported. The clinical spectrum of chikungunya ranges from an acute self-limiting form to disabling chronic forms. The purpose of this study was to estimate the seroprevalence of chikungunya infection in a large Brazilian city and investigate the association between viral circulation and living condition. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a population-based ecological study in selected Sentinel Areas (SA) through household interviews and a serologic survey in 2016/2017. The sample was of 1,981 individuals randomly selected. The CHIKV seroprevalence was 22.1% (17.1 IgG, 2.3 IgM, and 1.4 IgG and IgM) and varied between SA from 2.0% to 70.5%. The seroprevalence was significantly lower in SA with high living conditions compared to SA with low living condition. There was a positive association between CHIKV seroprevalence and population density (r = 0.2389; p = 0.02033). CONCLUSIONS/SIGNIFICANCE: The seroprevalence in this city was 2.6 times lower than the 57% observed in a study conducted in the epicentre of the CHIKV epidemic of this same urban centre. So, the herd immunity in this general population, after four years of circulation of this agent is relatively low. It indicates that CHIKV transmission may persist in that city, either in endemic form or in the form of a new epidemic, because the vector infestation is persistent. Besides, the significantly lower seroprevalences in SA of higher Living Condition suggest that beyond the surveillance of the disease, vector control and specific actions of basic sanitation, the reduction of the incidence of this infection also depends on the improvement of the general living conditions of the population

Previous BCG vaccination is associated with less severe clinical progression of COVID-19

BACKGROUND: BCG vaccination, originally used to prevent tuberculosis, is known to "train" the immune system to improve defence against viral respiratory infections. We investigated whether a previous BCG vaccination is associated with less severe clinical progression of COVID-19 METHODS: A case-control study comparing the proportion with a BCG vaccine scar (indicating previous vaccination) in cases and controls presenting with COVID-19 to health units in Brazil. Cases were subjects with severe COVID-19 (O2 saturation < 90%, severe respiratory effort, severe pneumonia, severe acute respiratory syndrome, sepsis, and septic shock). Controls had COVID-19 not meeting the definition of "severe" above. Unconditional regression was used to estimate vaccine protection against clinical progression to severe disease, with strict control for age, comorbidity, sex, educational level, race/colour, and municipality. Internal matching and conditional regression were used for sensitivity analysis. RESULTS: BCG was associated with high protection against COVID-19 clinical progression, over 87% (95% CI 74-93%) in subjects aged 60 or less and 35% (95% CI - 44-71%) in older subjects. CONCLUSIONS: This protection may be relevant for public health in settings where COVID-19 vaccine coverage is still low and may have implications for research to identify vaccine candidates for COVID-19 that are broadly protective against mortality from future variants. Further research into the immunomodulatory effects of BCG may inform COVID-19 therapeutic research