Adsorption of BTX (benzene, toluene, o-xylene, and p-xylene) from aqueous solutions by modified periodic mesoporous organosilica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The capacity of a periodic mesoporous organosilica (PMO) to adsorb the aromatic compounds benzene, toluene, o-, and p-xylenes (BTX), which are usually present in produced waters, was investigated under both column and batch processes. The PMO was synthesized by condensation of 1,4 bis(triethoxisilyl)benzene (BTEB) under acidic conditions by using structure-directing agent (SDA) Pluronic P123 in the presence of KCl. Thermogravimetric analysis showed that the presence of the surfactant decreases the thermal stability of the PMO. The small-angle X-ray diffraction pattern, as well as the nitrogen adsorption/desorption isotherm measurements, revealed that the synthesized material has a crystalline structure, with hexagonally-ordered cylindrical mesopores. The adsorption kinetics study indicated an adsorption equilibrium time of 50 min and also showed that the data best fitted the pseudo-first order kinetic model. The intraparticle diffusion model was also tested and pointed to the occurrence of such process in all cases. Both Langmuir and Temkin models best represented the adsorption isotherms of toluene: Langmuir and Redlich-Peterson models best represented the data obtained for the other compounds. Adsorption capacity decreases in the order benzene > o-xylene > p-xylene > toluene. Satisfactory results were observed in the application of the synthesized PMO for the removal of BTX from aqueous solution. (C) 2011 Elsevier Inc. All rights reserved.3632626634Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [486059/2007-3

Influência das condições socioambientais na prevalência de hipertensão arterial sistêmica em duas comunidades ribeirinhas da Amazônia, Brasil

This article discusses the influence of environmental conditions on the prevalence of systemic hypertension in two riverine communities in the Sustainable Development Reserve of Tupé, Manaus, Amazonas, Brazil, through an ecological study of multiple groups and contextual analysis carried out with the local inhabitants. To identify the environmental etiology describing the risk of disease development, the study compares demographics, incidence rates and common daily practices in these communities, using data collected in the field, between 2012 and 2014, as well as values provided by IBGE, originally from National Health Survey, 2013. The results suggest that social and environmental determinants, such as general living conditions, occupation and access to protective health care, in the investigated communities, are relevant factors in explaining the observed variability in systemic arterial hypertension (SAH) incidence rates. The study concludes by pointing out the importance and need to consider socio-environmental vulnerability in the elaboration of public health policies and in the management of environmentally protected areas. © 2018, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. All rights reserved

Segurança alimentar e nutricional: a produção do conhecimento com ênfase nos aspectos da cultura Feeding and nutritional security: the construction of knowledge with emphasis on cultural aspects

Este ensaio sobre segurança alimentar e nutricional tem como objetivos enfatizar a importância dos aspectos culturais para avaliar políticas de alimentação e nutrição, e contribuir com o debate nos centros de ensino interessados em pesquisas sobre o tema. A estrutura desse objeto envolve diversas disciplinas, inclusive as que se referem ao direito e à cultura. Fez-se a revisão da bibliografia pertinente para contextualizar a problemática da segurança alimentar e nutricional nas esferas macro e micro social. Também, foram analisados documentos oficiais e realizadas reflexões a partir de estudos antropológicos e exemplos de situações interligadas ao assunto, na expectativa de sedimentar algumas noções conceituais que contemplem aspectos da cultura, para enriquecer a avaliação de políticas sociais sobre segurança alimentar e nutricional. Destacou-se a abordagem antropológica para desvendar os significados da fome crônica, um dos efeitos mais perversos da insegurança alimentar. Concluiu-se que a compreensão dos aspectos culturais cria uma nova perspectiva analítica para estudos da eficácia da segurança alimentar e nutricional, para além do campo explicativo e normativo do modelo biomédico.<br>This essay on food safety stresses the importance of cultural aspects in assessing food and nutrition policies. It thus intends to contribute to topic discussions in educational centers interested in research on this issue. Such an objective involves various disciplines, including those concerned with law and culture. A bibliographical review was carried out in order to contextualize food and nutritional safety problems within the macro and micro-social spheres. Anthropological studies, the analysis of official documents and sample situations related to the subject were considered in an attempt to strengthen concepts comprising cultural aspects in order to improve the evaluation of social policies on nutritional and food safety. The anthropological approach is emphasized for an understanding of the diverse meanings of chronic hunger, one of the most perverse effects of food and nutritional insecurity. It was concluded that a better understanding of cultural factors brings forth a new analytical perspective for the study and evaluation of the efficacy of food and nutritional safety, beyond the explanatory and normative scope of the biomedical model