Benzoic acid solubility has been measured in pure water and in the binary mixtures containing different solvents including water, N,N-dimethylformamide (DMF), ethanol, or 1,4-dioxane. The experiments were carried out employing the cell used in Oliveira's dissertation. The temperature dependence of the solubility of an acid in two solvents could be evaluated. There was similar influence of the temperature in the solubility of benzoic acid in mixtures of water + DMF and water + 1,4-dioxane. An increase in acid solubility was observed with temperature in all mixtures. Addition of more ethanol in water favors the solubilization of benzoic acid.

This study aimed at providing experimental liquid-liquid equilibrium (LLE) data for aqueous two-phase systems (ATPSs) formed by poly (ethylene glycols) (PEG) of different molecular weights (1500 or 4000 or 6000) g.mol À1 and sodium thiosulfate pentahydrate at different temperatures (293.15e313.15) K and under atmospheric pressure. Correlations of experimental data of binodal curves were carried out using the Merchuk methodology. The effects of temperature, polymer molecular weight and of the nature of the anion of salts on binodal curves were discussed. In comparison with other anions previously investigated, the salting-out ability of the thiosulfate anion was between those of citrate and tartrate anions. Finally, the Othmer-Tobias and Bancroft equations and the NRTL activity coefficient model were used for correlating tie line compositions.

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In this paper the environmental evaluation of the separation process of the microalgal biomass Scenedesmus sp. from full-scale photobioreactors was carried out at the Research and Development Nucleus for Sustainable Energy (NPDEAS), with different flocculants (iron sulfate - FeCl, sodium hydroxide - NaOH, calcium hydroxide - Ca(OH) and aluminum sulphate Al(SO), by means of the life cycle assessment (LCA) methodology, using the SimaPro 7.3 software. Furthermore, the flocculation efficiency by means of optical density (OD) was also evaluated. The results indicated that FeCl and Al(SO) were highly effective for the recovery of microalgal biomass, greater than 95%. Though, when FeCl was used, there was an immediate change in color to the biomass after the orange colored salt was added, typical with the presence of iron, which may compromise the biomass use according to its purpose and Al(SO) is associated with the occurrence of Alzheimer's disease, restricting the application of biomass recovered through this process for nutritional purposes, for example. Therefore, it was observed that sodium hydroxide is an efficient flocculant, promoting recovery around 93.5% for the ideal concentration of 144 mg per liter. It had the best environmental profile among the compared flocculant agents, since it did not cause visible changes in the biomass or compromise its use and had less impact in relation to acidification, eutrophication, global warming and human toxicity, among others. Thus, the results indicate that it is important to consider both flocculation efficiency aspects and environmental impacts to identify the best flocculants on an industrial scale, to optimize the process, with lower amount of flocculant and obtain the maximum biomass recovery and decrease the impact on the extraction, production, treatment and reuse of these chemical compounds to the environment. However, more studies are needed in order to evaluate energy efficiency of the process coupled with other microalgal biomass recovery technologies. In addition, studies with natural flocculants, other polymers and changes in pH are also needed, as these are produced in a more sustainable way than synthetic organic polymers and have the potential to generate a biomass free of undesirable contaminants.

Dados de equilíbrio p-V-t isotérmicos são coletados para o ar de 23 ºC a 60 ºC na faixa de pressão de 1,04 atm até 1,73 atm. O equipamento experimental consiste de uma célula que é termostatizada por um banho. Os resultados permitem verificar as leis de Boyle-Mariotte e Gay-Lussac, tão bem quanto a equação dos gases ideais.

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Introdução/objetivo A COVID-19 é uma doença associada a quadros respiratórios agudos, que já causou a morte de mais de 4.800.000 pessoas em todo o mundo. A pressão sobre os sistemas de saúde, o aumento de internações em UTI e, consequentemente, do uso de antimicrobianos levaram a um aumento considerável nas taxas de Infecções Relacionadas à Assistência à Saúde (IRAS) e na ocorrência de microrganismos multirresistentes (MR). Este trabalho objetiva descrever o perfil de pacientes com COVID-19, internados na UTI de um hospital de referência, localizado em Belo Horizonte/MG, identificando fatores associados à ocorrência de IRAS e infecção por microrganismos MR, e o desfecho clínico desses pacientes. Métodos Análise retrospectiva do banco de dados do Serviço de Controle de Infecção Hospitalar, contendo informações clínicas de pacientes adultos, com RT-PCR ou teste de antígeno positivos para COVID-19, internados na UTI, no período de março de 2020 a agosto de 2021. Resultados Foram analisados 436 pacientes, sendo que a mediana de idade foi 68 anos. 352 (80,7%) pacientes necessitaram de ventilação mecânica (VM). A taxa global de letalidade por COVID-19 foi 57,8%, sendo que a letalidade até 7 dias foi 4,6%, e até 30 dias, 37,8%. 198 (45,4%) pacientes apresentaram IRAS, com letalidade de 70,7%. Infecção Primária da Corrente Sanguínea Laboratorial (IPCSL) foi a infecção mais frequente (97, 49,0%), seguida por Pneumonia Associada a Ventilação (PAV), com 59 casos, 29,8%. A mortalidade por IRAS foi 32,1%. A densidade de incidência (por 1.000 procedimentos-dia) de IPCSL associada a cateter venoso central (CVC), PAV e Infecção do Trato Urinário associada a sonda vesical de demora foram, respectivamente, 17,1, 10,1, 2,6. Entre os microrganismos multirresistentes, o mais frequente foi Klebsiella pneumoniae, seguido por Acinetobacter baumannii e Pseudomonas aeruginosa, resistentes a carbapenêmico. Houve uma associação entre infecção e o tempo de uso de CVC (20,42 × 10,16 dias, p < 0,001). Uso prévio de meropenem também se associou à infecção (p < 0,01). Conclusão: COVID-19 é uma doença de elevada letalidade. A ocorrência de IRAS contribui para os óbitos. A IPCSL é a infecção mais frequente, tornando fundamental o treinamento das equipes quanto aos cuidados na manipulação de CVC. Uso prévio de carbapenêmico associa-se à ocorrência de IRAS por microrganismos MR, sendo importante o funcionamento de programas de stewardship de antimicrobianos.