Role of the sediments of two tropical dam reservoirs in the flux of metallic elements to the water column

In tropical climates, the high rainfall and temperature, throughout the annual cycle, allow high leaching rates of metallic elements from the basin upstream, which accumulate in the reservoirs. However, the concentration of these elements in natural waters is usually lower than expected, due to the ease of adsorption and co-precipitation in solid phases. We have studied two tropical dam reservoirs in Brazil, Três Marias (Minas Gerais) and Tucuruí (Pará), with the aim of understanding the correlation between physical–chemical parameters of the water column, chemical and mineralogical characteristics of the accumulated material and the solubility, mobilization and precipitation of metals in reservoirs. Metals speciation performed in selected samples determined that metallic micronutrients are preferentially adsorbed or retained through precipitation/co-precipitation onto fine-size charged crystalline/amorphous Fe-oxides. Under the prevailing reducing and low pH conditions of the bottom reservoirs, some adsorbed metals (particularly Fe and Mn) are easily released from their metal bearing-phases and mobilized to the aqueous phase of sediments, which show high levels of soluble forms of these elements. However, the solubilization process and the release to the water column are not very extensive, as abundances of metals such as Fe, Mn, Zn and Cu in water are low, although increasing with dept

Internet of things e a sustentabilidade nas cidades inteligentes

Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementA tecnologia está a evoluir a uma velocidade exponencial, está a tornar-se cada vez mais útil e a espalhar-se por imensas áreas onde até há pouco tempo não existia. Dado o seu desenvolvimento e omnipresença pode ser aproveitada para mitigar e acabar com muitos problemas que hoje existem. As alterações climáticas são o grande problema aqui tratado e, uma vez que é complexo e que exige grande dedicação para que não se agrave, é necessário agir. Os contributos para este problema continuar a crescer são vários e é necessário saber como os mitigar, eliminar ou contornar. Será feita uma investigação com foco nos problemas que causam as alterações climáticas para depois entrar-se numa investigação com foco numa das tecnologias mais faladas e debatidas do momento, Internet of Things. Sendo as cidades as maiores contribuintes para o aquecimento global, serão identificadas e analisadas tecnologias IoT que podem contrariar esta tendência, construindo-se um referencial que as associará às cidades

Acompanhamento da construção do Centro Escolar do Agrupamento nº 1 de Beja Escola EB1 de Santa Maria

O presente relatório traduz a sequência do Estágio Curricular realizado na Câmara Municipal de Beja, ao longo de 4 meses. Procurei com este documento, reflectir os conhecimentos adquiridos no decurso do estágio, sobretudo através da experiência que me foi concedida em poder viver o dia-a-dia de um Engenheiro Civil em obra, neste caso a construção do Centro Escolar do Agrupamento Nº 1 de Beja (Escola EBI Santa Maria). A estrutura do relatório está dividida em 4 partes, respeitantes essencialmente à construção da referida Escola. Uma introdução que aborda especificamente os objectivos do presente relatório, um capítulo que abrange o acompanhamento de todas as fases da construção da Escola Básica Nº1 e Jardim de Infância de Santa Maria, complementado com fotografias, um outro capítulo que integra os aspectos mais importantes sobre a Higiene e Segurança em Obra e ainda um outro sobre a Direcção e Fiscalização de Obra, que permitiu optimizar a gestão do processo construtivo. São também referidas outras obras acompanhadas ao longo do Estágio e finalmente a conclusão retirada deste percurso relevante para a aquisição de experiências de qualquer Engenheiro Civil recém-formado

Assessing the impact of metals loads and other contaminants in large freshwater bodies using hyperspectral remote sensing. A challenge for the future of lakes and rivers management

The use of remote sensing to estimate water quality parameters, such as suspended sediments, metals and nutrients distribution, seems to be a useful technology to use as a preliminary study in large freshwater bodies. Empirical models based on the relationships between spectral measurements and water and sediments quality analytical data, will decrease the number of sampling sites in the basin, since remote sensing is a considered a potential method to estimate water quality variations. In order of having a synergy between hyperspectral data and geochemical, mineralogical and hydrological information, we would like to use the hyperspectral remote sensing technology in two different scenarios: (1) A contamination area by intense agriculture and (2) A contamination area by mine industry

Food waste accounting - Methodologies, challenges and opportunities

Food waste (FW) is a priority both at global and European level. The United Nations (UN) defined the Sustainable Development Goal 12.3 target of ‘By 2030, halve per capita global FW at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses’. The European Commission has committed to achieve this goal and defined FW as a priority within the Circular Economy Action Plan. In order to support achievement of the SDG 12.3 target on food waste and maximise the contribution of all actors, the Commission to established the EU Platform on Food Losses and Food Waste (FLW) to support all actors in defining measures needed to prevent food waste, sharing best practice, and evaluating progress made over time. The first step to address FW is to have a robust account of FW generated along the Food Supply Chain (FSC). Studies can be found in the literature that estimate FW at the EU level but results are discrepant because of different approaches, e.g. inclusion of inedible fractions of food and type of measurement. Furthermore, each approach presents strengths and weaknesses that may influence its use for specific purposes. At present, a consolidated framework for FW quantification in Europe is still an open challenge. A robust FW accounting system and FW quantification is primordial to enable monitoring FW and measuring distance to FW reduction targets. Such information is necessary to identify the most important FW streams, to define a baseline to monitor FW reduction over time, and to recognise FW flows that may undergo a valorisation process in a circular economy perspective To contribute to the development of harmonized and robust FW accounting methodologies and FW quantification, the Joint Research Centre (JRC), bioeconomy unit (D1) organized a technical workshop entitled ‘Food waste accounting: methodologies, challenges and opportunities’ with speaker’s representative of the main projects related to FW accounting. The aim of the workshop was to share experiences and perspectives on FW quantification at the European scale, highlighting opportunities and challenges in order to improve FW quantification and ensure better decision support in relation to FW reduction and valorisation. A key message from the workshop was that a harmonize methodology for FW accounting is not yet defined and there is the need of improving and matching methodological aspects and policy questions as the information needs are different depending on the area of policy intervention (either prevention, management or valorisation). Together with a clear framework for FW accounting, a clear and consensual FW definition clearly and in standardized way the aim, definitions and terminology (edible/inedible and avoidable/unavoidable), system boundaries, and, units of measurement is very important. This involves defining. This would enable the comparison of existing data across countries, commodities, and FSCs, which would further help exploring patterns and driving factors of FW generation. It was also identified the need to improve data quality and the development of methods to account liquid waste. Moreover, research is necessary to identify systematically types and sources of uncertainty and variability within the FW accounting framework and provide guidelines and tools to assess them. Another challenge to be addressed is the identification of FW drivers is of extreme relevance for both designing properly the framework for primary data collection and defining effective reduction strategies.JRC.D.1-Bio-econom

Geochemistry of metals in the bottom sediments of tropical dam reservoirs in San Francisco River (Três Marias, MG) and Tocantins River (Tucuruí, PA), Brazil.

In tropical climates, the high rainfall and temperature, throughout the annual cycle, allow high leaching rates of metallic elements from the basin upstream, which accumulate in the reservoirs. However, the concentration of these elements in natural waters is usually lower than expected, due to the easiness of adsorption and co-precipitation in solid phases. We have studied two tropical dam reservoirs in Brazil, Três Marias (Minas Gerais) and Tucuruí (Pará), with the aim at understanding the correlation between physical-chemical parameters of the water column, chemical and mineralogical characteristics of the accumulated material and the solubility, mobilization and precipitation of metals in reservoirs. Metals speciation performed in selected samples assess that metallic micronutrients are preferentially adsorbed or retained through precipitation/co-precipitation onto fine-size charged crystalline/amorphous Fe-oxides. Under the prevailing reducing and low pH conditions of the bottom reservoirs some adsorbed metals (particularly Fe and Mn) are easily released from their solid hosts and mobilized to the aqueous phase of sediments, which show high levels of soluble forms of these elements. However, the solubilisation process and the release to the water column are not very extensive, as abundances of metals such as Fe and Mn in water are low, although increasing with depth