Browsing by Issue Date, starting with "2006-09"
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- Lead bioremoval by cork residues as biosorbentPublication . Mota, Dora; Marques, Paula; Rosa, Maria Fernanda; Gil, Luís; Marques, Carlos PereiraThe intensification of industrial activity during the last few years has greatly contributed to the increase of heavy metals in the environment, mainly in the aquatic systems [1]. Conventional technologies traditionally used for the removal of heavy metals from aqueous solutions are expensive and inefficient at low metal concentrations [2]. Biosorption, which is a property of different types of biomass (biosorbents) to bind and concentrate heavy metals from even very dilute aqueous solutions, is one of the most promising technologies that can be used for this purpose [3]. The goal of this work was to study the bioremoval process of Pb(II) ions from aqueous dilute solutions by cork granulates (1-2 mm) from a Portuguese cork processing company. The effect of physico-chemical parameters such as initial metal solution, pH, biomass cork pre-treatments and initial metal and biosorbent concentrations on the metal removal efficiency were investigated. The maximum Pb(II) uptake capacity (Qmax) of cork biomass was also determined from the Langmuir isotherm. The results obtained showed that the optimum initial pH for Pb(II) removal was in the range 3-4, leading to removal yields of about 90-100% for initial metal concentrations of 10-100 mg/L. Cork biomass without treatment provided a higher removal yield (93%) than the biomass submitted to previous extraction with deionised water (80%), ethyl acetate (83%) and ethanol (88 %). The Langmuir model showed a very good correlation with experimental results (r2=0.995) and the Qmax was determined as being 5.3 mg Pb(II)/g cork. The optimisation of continuous bioremoval of Pb(II) (10 mg/L) from 25 L of influent, regarding metal uptake yield and volume of effluent containing a Pb(II) concentration 1 mg/L (MAV), was carried out by the factorial design methodology, leading to the establishment of the best operating conditions. In these conditions, two fixed bed-reactors (operational liquid volume of each reactor containing 20g of biosorbent=138 mL) running in sequential mode (feed flow rate - 590 mL/h) were more efficient (effluent volume with [Pb(II)] 1 mg/L=10 L) than one reactor alone (effluent volume with [Pb(II)] 1 mg/L=5 L). Finally, the chemical characterization in terms of CQO, TOC and phenolic compounds of the effluent before discharge showed that all values were lower than the ones allowed by environmental legislation.
- Petrological and thermochronological constraintson the geodynamic evolution of the Ribeira Fold BeltPublication . Tassinari, Colombo C. G.; Munhá, José; Neto, Coriolano Dias; Santos, Teresa; Cordani, Umberto G.; Nutman, Allen P.; Fonseca, Paulo E.
- Air flow exchange velocity of urban canyon cavities due to thermal spatial differencesPublication . Panão, Marta Oliveira; Goncalves, Helder; Ferrão, PauloIn this paper, the air exchange velocity between the urban canyon cavity and the air layer above roof level is quantified, using a two-dimensional k-ε model, and correlated with the air cavity mean temperature, for two cases: leeward and downward wall heating. The spatial thermal differences are evaluated by assuming a wall temperature higher than the air temperature, with this difference ranging between 0 and 16 K. The undisturbed wind velocity above the roof level is varied from 1 to 6 ms-1 and the canyon aspect ratio is 1.5, which corresponds to a skimming flow regime. The model predicts two situations, which correspond to air flow regimes where one or two eddies are formed, respectively: (a) for high wind speed, the air inside the cavity is negligible affect by the buoyancy effect and the air exchange velocity linearly increases with the increase of wind velocity; (b) for low wind speed, when the buoyancy forces are stronger than the wind induced forces, the air exchange velocity is not a linear function with the wind velocity. The transition wind velocity between (a) and (b) is a function of the wall-air temperature difference. The situation of windward heated wall and two eddies air flow regime is the most favorable to extract heat from the cavity. On the contrary, the heated air is hardly extracted from the cavity when only the wind induced eddy is predicted and windward wall is heated. In this situation an increase of 10 K on the wall temperature increases by 1 K the in-cavity air temperature.
- How to measure the value from a sustainable point of viewPublication . Alexandre, Jorge; Maia, Anabela; Camocho, David; Rodrigues, Fátima; Henriques, José João M. Silva; Catarino, JustinaEntrepreneurial activities must change when taking into account Sustainable Development paradigm. A new way of evaluating enterprises’ performance which incorporates economical, environmental and social criteria is necessary. Any organisation can no longer work as a “black box”. Society wants to know about the impacts of inputs and outputs of companies’ activities and therefore a continuous process of transparency, communication and continuous improvement is required. Therefore the Value of a company can no longer be seen only as the profi t for its shareholders, but must be extended in an objective way to the other elements of Sustainability: the social and environmental criteria. If Top Management and the VA team are sensitized for the Sustainability principles and for their contribution in creating Value, these aspects will be integrated in the company’s strategic management so that they will contribute for its viability in the long term. This paper aims at presenting a specifi c methodology to support the process of decision making at the level of the practices related to increasing Value towards a Sustainable Entrepreneurial Development. After a study of the possible synergies between tools used by Value Management (mainly Value Analysis) and Environmental Management (Cleaner Production, Eco effi ciency, among others) a methodology, joining them and profi ting from their synergies was developed and tested in several companies.
- GreenMed: inovar nas compras públicas ambientalmente orientadas em PortugalPublication . Trindade, Paula; Duarte, Ana Paula; Fernandes, Andreia; Vivas, Paulo; Duarte, Ezequiel; Ribeiro, Carla; Frade, Margarida; Pedro, Sandra; Gomes, MyleneAs aquisições públicas Ambientalmente Orientadas (GPP) constituem uma metodologia para a integração sistemática de critérios ambientais nos procedimentos de aquisição de produtos e/ou serviços por parte da administração pública. O projecto GreenMed teve a duração de 3 anos e foi financiado pelo programa LIFE-Ambiente. Tem como objectivo promover práticas de aquisições públicas ambientalmente orientadas nos países mediterrânicos através do desenvolvimento de ferramentas inovadoras e de planos de acção neste domínio. Os grupos alvos deste projecto são as autoridades locais da Grécia e de Portugal. Este projecto inovador em Portugal teve a coordenação científica do CENDES - Centro para o Desenvolvimento Empresarial Sustentável do Instituto Nacional de Engenharia, Tecnologia e Inovação (INETI), tendo sido aplicado na Câmara Municipal de Torres Vedras. O projecto contou ainda com parceiros gregos, nomeadamente o município de Neo Psychico, tendo sido trocada experiência entre Portugal e a Grécia
- Normalização em ética e responsabilidade social: desenvolvimentos em PortugalPublication . Duarte, Ana Paula; Sousa Rocha, Cristina; Frazão, RuiA Organização Internacional de Normalização (ISO) está a desenvolver a Norma Internacional de Responsabilidade Social (Norma ISO 26000), com publicação prevista para 2008, que constituirá um guia sobre esta matéria, tendo encorajado por outro lado todos os países participantes a desenvolver as suas próprias normas nacionais sobre a mesma temática. Portugal vem participando nestes esforços através da APEE (Associação Portuguesa de Ética Empresarial), na sua qualidade de Organismo de Normalização Sectorial para os domínios da Ética Empresarial e Responsabilidade Social, que lançou as Comissões Técnicas CT 164 Responsabilidade Social e CT 165 Ética Empresarial, no âmbito do Sistema Português de Normalização. A CT 164 tem o mandato de acompanhar e contribuir para os desenvolvimentos da Norma ISO e, ainda mais importante, de elaborar uma Norma Portuguesa de Responsabilidade Social (RS), como resposta ao interesse crescente por parte das empresas e de outras organizações em actuar reconhecidamente em prol da sustentabilidade, e ao repto da própria ISO, que encorajou os diversos países a elaborarem as suas normas nacionais de RS. É de referir que o trabalho em Portugal se tem desenvolvido em articulação com o da também recém-criada CT 165 Ética Empresarial, cujo principal objectivo é o desenvolvimento de uma norma sobre a elaboração e implementação de códigos de ética em organizações. Por outro lado, o Fórum de Ética e Responsabilidade Social é composto por entidades representativas de seis categorias de partes interessadas (stakeholders), definidas pela ISO, ou seja, Empresas, Organizações Laborais, Organizações Não Governamentais, Organizações de Consumidores, Organizações Governamentais e Serviços, Suporte, Investigação e Outros. O Fórum tem a função de Mirror Committee do ISO/TMB/WG SR e, sobretudo, de contribuir activamente para o desenvolvimento dos projectos de Normas Portuguesas de Responsabilidade Social e de Elaboração e Implementação de Códigos de Ética em organizações, em estreita colaboração com a CT 164 e a CT 165.