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Bioelectrochemical systems (BESs) are developed to transform the energy harvested from the biomass into electricity. Different types of BESs including microbial fuel cell (MFC), microbial electrolysis cell (MEC), and microbial desalination cell (MDC) are under intensive research and development; however, their life cycle environmental impacts have not been systematically compared to identify the most environmentally friendly BES. To understand and eventually help reduce the environmental impacts of different BESs, life cycle assessment (LCA) models were developed in this study to assess and compare their potential environmental impacts. The results indicate that the MEC has better environmental performance than the MFC and MDC due to the large hydrogen peroxide production in the operation phase. The environmental performance of the MFC and MDC can be improved by the increase of power density, but their environmental impacts, at a relatively high power density that can be achieved by current technology, are still higher than the environmental impacts of the MEC at current power density. When the environmental impacts are benchmarked with those of the traditional wastewater treatment methods, the MEC has a better environmental performance, whereas the MFC and MDC have relatively large environmental impacts. This publication is made possible by NPRP # 6-289-2-125 from Qatar national research fund (a member of Qatar foundation).

This study presents a state of the art and design proposal for membrane sunspaces, as alternative to conventional ones, in glass, commonly used in the functional refurbishment of old buildings. Sunspaces are passive solar systems that can be easily integrated in existing buildings. Enclosing balconies with glazing has an impact on existing building functional performance (useful area, thermal performance and acoustic improvement) and it may even postpone the renovation need of the intervened building. However, inevitably, many of old buildings are located in areas with access restrictions and other physical constraints on the movement of materials, components and equipment - that limits its construction and maintenance processes and thus demand for alternative solutions. Glass is being applied in all types of sunspaces, so architects and engineers take for granted that it has to be inevitably used. However, a major weakness of glass is its weight and cost, specially associated with installation complexity, framing systems and accessories needed. The fact that membrane requires less substructure, changes the architectural approach - giving more freedom to design options. Membrane construction technology and installation process could be a practical alternative to traditional construction methods for closing balconies in old buildings. For this research, a full-scale Membrane Alternative Sunspace prototype was implemented into an old building (taken as case study) to evaluate the real construction process aspects and compare it with the common glazed solutions. Results were examined from an environmental, economic and building technology's point of view - regarding production, construction and maintenance phases., First author thanks to FCT (Fundacao para a Ciencia e Tecnologia - Portugal), MCE (Ministerio da Educacao e Ciencia - Portugal) and ESF (European Social Fund) for supporting the research fellowship with the reference SFRH/BD/104891/2014; and with other authors thanks the financial support from the Project UID/AUR/04509/2013 by FCTMEC by national funding and, when applicable, FEDER co-financing under the new PT2020 partnership agreement - Lab2PT, School of Architecture/University of Minho, Portugal and Project POCI-01-0145-FEDER-007457 - CONSTRUCT Institute of R&D In Structures and Construction of Faculty of Engineering/University of Porto, Portugal, funded by FEDER funds through COMPETE2020. Authors also thanks to: owners of the building case study, that allow the MAS1 full-scale prototype integration on it; and Floret architecture firm that provides case study building designs. Also thanks to Bionova Ltd for provide a One Click LCA student license.

The reduction of CO2 emissions is an urgent objective to pursue. The scientific and the industrial world have gathered such challenge, starting to find out energy- and resource-efficient manufacturing strategies. From the literature review, in the domain of environmental impact analysis of manufacturing processes, two relevant knowledge gaps can be spotted: (1) the metal forming processes (and, in particular, the bulk forming processes) are still not well documented, and (2) there is a lack of systematic and comparative studies on energy and material flows enabling the identification of environmentally-friendly manufacturing design strategies. This research offers a contribution to a better understanding of the environmental impact of forming and machining processes. The performance of the two processes is evaluated and compared with the varying of the material usage related factors. The impacts on the final results of the aluminum recycling strategy as well as of the applied method to account for benefits of recycling are analyzed. Therefore, the paper represents an effort aimed at tuning and improving a methodology able to thoroughly analyze the environmental impact of a given process, and to better compare different manufacturing strategies from the environmental point of view.

The scientific studies in the domain of environmental sustainability of metal processing technologies predominantly focus on conventional material removal processes, as milling and turning. Despite some exceptions, many other non-machining technologies, such as metal forming processes, are still not well documented in terms of their energy and resource efficiency. Moreover, to properly evaluate the environmental impact of a given process, a standing-alone approach is no longer sufficient. In order to offer a valuable contribution in the domain of metal shaping sustainability, the present paper proposes a thorough methodology entailing to compare, from the environmental point of view, two traditional technologies: a hot extrusion process (mass conserving approach) and a turning (subtractive) one. A Life Cycle Assessment (LCA) based approach is implemented to properly analyze the considered processes. An axi-symmetric aluminum component was selected to develop the analysis on. Besides the analysis of material flows occurring all along the life cycle of the component, the material use and the consumed electrical energy necessary for the tools manufacturing are measured to properly quantify the environmental impact of the production phases. The most relevant influencing factors within each technology are identified and quantified. Moreover, an analysis of the environmental performance of the two processes at the varying of the batch size is presented. The paper aims at providing some general guidelines for the identification of the greenest technology as the main influencing factors change. © 2014 Elsevier Ltd. All rights reserved.