RESUMOA contaminação de águas por espécies tóxicas ou recalcitrantes gera grandes impactos ambientais. Nesse contexto, os Processos Oxidativos Avançados (POAs), tecnologias que utilizam principalmente o radical hidroxila (HO • ) para a oxidação dos poluentes, têm se destacado como métodos alternativos promissores no tratamento de águas residuais e efluentes industriais. Os POAs têm sido considerados uma estratégia eficaz do ponto de vista técnico, econômico e ambiental para a degradação de poluentes presentes em águas residuais e efluentes industriais, apesar de possuir limitações como alto custo das fontes de energia, desenvolvimento de novos materiais catalíticos de baixo custo e construção de reatores em escala real. Há uma grande relevância na aplicação desses processos em escala industrial mediante a otimização desses fatores de eficácia. Sendo assim, o objetivo deste trabalho foi realizar um levantamento bibliográfico sobre os POAs e apresentar dados a respeito da eficiência desses processos na degradação de poluentes, comparando os embasamentos teóricos e a sua aplicação industrial. Diante disso, os fundamentos e aplicações dos principais POAs (químicos, fotoquímicos, eletroquímicos, sonoquímicos, sonoeletroquímico e processos baseados em ozônio), bem como suas vantagens e desvantagens foram descritos nesta revisão da literatura.

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The aim of the present study was to investigate the electrochemical formation of free chlorine species (HOCl/ClO) and their subsequent use for the degradation of the pesticide atrazine. Initially, the process of electrochemical-free chlorine production was investigated using a bench-scale electrochemical flow-cell. The most significant variables (electrolyte concentration ([NaCl]) and inter-electrode gap) of the process were obtained using a 2 factorial design and the optimum process conditions (1.73 mol L and 0.56 cm) were determined by a central composite design. Following optimization of free chlorine production, three degradation techniques were investigated, individually and in combination, for atrazine degradation: electrochemical, photochemical and sonochemical. The method using the techniques in combination was denominated sono-photo-assisted electrochemical degradation. Constant current assays were performed and the sono-photo-assisted electrochemical process promoted more efficient removal of atrazine, achieving total organic carbon removal of ∼98% and removal of atrazine to levels below the detection limit (>99%) in under 30 min of treatment. Furthermore, the combination of three techniques displayed lower energy consumption, and phytotoxicity tests (Lactuca sativa) showed that there was no increase in toxicity.

IntroductionThe inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.ObjectiveIn order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.MethodsFor this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH2O.ResultsWe observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.ConclusionWe conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.