Browsing by Issue Date, starting with "2009-11"
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- A contaminação por TNT e DNT das águas subterrâneas do SeixalPublication . Amaral, Helena; Fernandes, Judite; Berg, Michael; Schwarzenbach, René P.; Kipfer, Rolf
- Novas tendências nos sistemas de digestão anaeróbica e produção de biogásPublication . Di Berardino, SantinoOs sitemas integrados de valorização energética e ambiental dos resíduos com base na digestão anaeróbica associada a práticas agrícolas, podem constituir uma oprtunidade de negócios e de desenvolvimento do meio rural. A tecnologia existente consegue satisfazer, vantajosamnete, as aplicações práticas, existindo soluções inovadoras que poderão permitir maiores rendimentos. O cultivo de terrenos com plantas herbáceas com resíduos digeridos, pode susbtituir vantajosamente as culturas de alto rendimento e ocupar e valorizar terrenos marginais. O biogás é um combustível muito versátil, que pode alimentar os dispositivos mais diversos, nomeadamente as células a combustível, as turbinas a gás ou pode ser convertido em biometano. Em Portugal estes sistemas têm difuculdade em avançar na implementação, pois existem barreiras técnicas, não técnicas e económicas que devem ser removidas.
- A qualidade das águas naturais portuguesas: minerais e de nascentePublication . Machado Leite, Mário
- On the Best Practice Implementation of Solar Thermal Obligations. The ProSTO EU Project and the Portuguese experiencePublication . Prates, Manuel João Lopes; Mendes, J. Farinha; Carvalho, Maria JoãoBased on the work that it is running within the ProSTO EU project (http://www.solarordinances.eu/), this paper presents a tentative approach to the best way for a successful implementation of a solar thermal obligation (STO) in a community. The EU framework, and base line assessment – including success factors and performance indicators were presented by the ProSTO coordinator elsewhere [1]. The Portuguese case was presented elsewhere too [2]. Here, all the complete set of measures that must be taken to succeed, will be presented. The experience shows that it is necessary to get an integrated “policy package” in the way of “zero building emissions”, around the kernel key point of clear requirements, aiming energy savings, namely for energy demand limitation, and energy efficiency of thermal installations. A parent kernel key point of this “policy package” is quality: certification of thermal solar system and components – solar collectors, factory made systems, and custom built systems; planner, designer and installer certification; technical impositions in the regulations (supported by a very consistent manual of actual good practices for solar thermal applications, with a flexible method to follow new developments); guarantee impositions (maintenance contract). All relevant documents of these quality items must be integrated in the Building Use Manual for easy management. Another kernel key point, this with focus on overcoming barriers, is that of public awareness, aiming to create an understanding that the implementation of a STO is not another awful bureaucratic burden, throughout on-line information (lists of certified equipments, installers, technical description of the equipments, manual of good practices, scholar materials (class notes, computer codes, homework assignments, etc.), etc.), and the implementation of training courses for all stakeholders.
- Impacto na saúde e medidas relacionadas com armas químicas e outros agentes químicos perigososPublication . Curto, Maria João Marcelo; Teixeira, Adriano; Ramalho, Luís; Costa, Maria do CéuNeste trabalho é abordado o impacto da utilização de produtos químicos perigosos em acções de terrorismo e são propostas medidas de intervenção que devem ter em conta os cenários previsíveis. Considerando-se primordial a protecção da saúde de grupos alvo, pretende-se sensibilizar as entidades responsáveis para medidas específicas a serem adoptadas por médicos, laboratórios, enfermeiros e brigadas de intervenção de peritos, cuja formação e treino contínuo são fundamentais para identificar e colmatar as carências estruturais e operacionais locais. Nesta comunicação discutimos os referenciais para cursos de formação e treino contínuo dos respondentes para colmatar as carências estruturais locais identificadas. Como um terrorista actua para destabilizar a sociedade, assegurar informação clara e fiável ao público é um elemento chave aqui também relevado para organizar a resposta a qualquer ataque terrorista.
- Physical and chemical processing of printed circuit boards wastePublication . Oliveira, Paula; Taborda, F. Charters; Margarido, F.; Nogueira, CarlosA recycling process for PCB’s is being studied, based on physical processing and hydrometallurgical treatment. PCB’s waste was shredded in a lab cutting mill, resulting a grinded material with 90% (weight) with particle size less than 2.1 mm and an average particle diameter of 1.2 mm. Chemical analysis of granulometric fractions showed that the base metals like Cu, Zn, Pb and Sn concentrated mainly in intermediate size fractions (0.4-1.7 mm) being fines very rich in epoxy resin composite. About 80-90% of the principal metals were recovered in that size range. The first step of chemical treatment was the acid leaching of metals. The use of nitric acid solutions at appropriate conditions allowed the efficient solubilization of base metals like Cu, Ni, Zn, Pb and Ag. More than 90% recovery of Cu, Zn and Ni were achieved at 90ºC using 1 M HNO3. Dissolution of silver required higher concentrations (only 70% yield using 2 M HNO3). Tin leaching was inefficient in nitric media, being always lower than 20%. The leaching conditions here reported were adequate to the base metals solubilization, allowing further processing of leachates for separation and recovery using hydrometallurgical operations. Precious metals recovery would be attained in a subsequent leaching step using highly concentrated acidic solutions.
- Leaching behavior of several zinc rich residues in a hydrometallurgical recycling processPublication . Pedrosa, Fátima; Cabral, Marta; Nogueira, Carlos; Margarido, F.The leaching of metals contained in spent Zn-MnO2 batteries and electric arc furnace (EAF) dusts using sulfuric acid solutions was studied, in order to evaluate the feasibility of simultaneous treatment of both wastes by a hydrometallurgical process. In both residues, a substantial quantity of zinc was solubilized (about 100% in batteries and 70-80% in EAF dusts) in diluted acid solutions and room temperature, corresponding to the reaction of zinc oxide species. Other species were more refractory to the chemical attack, namely the manganese (III or IV) oxides in batteries and the zinc ferrite in dusts, requiring higher temperatures (e.g. 90ºC) and higher leachant concentrations. Lead present in EAF dusts was not solubilized in sulfate media, thus remaining in the leach residue. Results seem to confirm the possibility of treatment of both zinc-containing residues by the same hydrometallurgical process, eventually involving two leaching stages – diluted acid leaching and hot acid leaching – followed by solution purification through iron precipitation and Zn/Mn separation and recovery. Concerning lead, a second leaching circuit in chloride media could be developed for its potential recovery.
- Contamination by heavy metals in aquatic trophic webs: the case of otter and red-swamp crayfishPublication . Henriques, J. F.; Santos, M. M. Correia dos; Trancoso, Maria Ascensão; Reis, M. Santos
- O consumo sustentável como um vector de mitigação das alterações climáticasPublication . Aguiar, Ricardo
- Habitação e Construção SustentávelPublication . Duarte, Ana Paula