The present study aims to treat some aspects of environmental contamination under the focus of the principle of precaution, which is based on ideas and discussion about the concerns of society regarding ethics, the environment, water resources, the risk of contamination, and the uncertainties of technological applications in all areas of human knowledge. In the assessment of these scenarios it was decided to evaluate, under a critical view, the chemicals used in the treatment of drinking water, which could cause health problems, directly or indirectly, in the population. Some samples of commercial aluminium sulphate were analysed, concluding that there was a need for physical and chemical assessments to identify the origins of the raw materials used in its manufacturing process.
The respective compounds of copper, cadmium and lead, owing to their strong toxic potential, as a result of industrial effluent, have left a trail of contamination in humans and the environment. This paper aimed to study the electrode position on the removal of aqueous solutions of cadmium, lead and copper, using an electrolytic cell with a metallic screen cathode of carbon steel and platinum anode. Removal efficiencies were obtained by analysis of the solutions before and after treatment, using the methodology of cathodic-stripping voltammetry with a mercury drop electrode to quantify the concentrations of Cd 2+ , Pb 2+ and Cu 2+. Removal efficiencies were obtained of 94.07% for cadmium, 94.71% for lead and 96.19% for copper, demonstrating that electrolytic removal is an effective technique for the removal of these metals from simulated industrial wastewater.
Resumo: Este trabalho examina implicações e desafios ao ensino de Ciências e Biologia emergentes da implantação de lei obrigando o ensino religioso na forma confessional no estado do Rio de Janeiro. Utilizamos como fonte cartas dos leitores de O Globo, além de outros pronunciamentos da mídia e textos acadêmicos. A polêmica do ensino religioso nas escolas públicas brasileiras aparece associada a novos elementos, incluindo pela primeira vez discussões ligadas não apenas a cidadania e liberdade religiosa, mas também ao confronto entre os pontos de vista criacionista e evolucionista, relativamente novo no Brasil, com enorme potencial de crescimento. Este cenário resulta da formação de novas alianças entre grupos religiosos disputando o espaço público com defensores da laicidade. Diante disso, reforçamos a importância das atividades de divulgação científica e de demarcação da natureza da Ciência, sendo especialmente importantes nesse sentido as contribuições da Filosofia e História da Ciência.
Elaborado por Maurício Amormino Júnior-CRB6/2422 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. 2019 Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.