This paper presents a novel argumentation framework to support Issue-Based Information System style debates on design alternatives, by providing an automatic quantitative evaluation of the positions put forward. It also identifies several formal properties of the proposed quantitative argumentation framework and compares it with existing non-numerical abstract argumentation formalisms. Finally, the paper describes the integration of the proposed approach within the design Visual Understanding Environment software tool along with three case studies in engineering design. The case studies show the potential for a competitive advantage of the proposed approach with respect to state-of-the-art engineering design methods.Keywords: argumentation; debate; design rationale; Issue-Based Information System (IBIS); decision support Engineering design is often described as an information-processing activity based on problem-solving within the constraints of bounded rationality (Simon, 1996;Simon & Newell, 1971). It consists of decomposing an initial problem into a range of sub-problems, proposing and assessing partial solutions, and integrating them as to satisfy the overall problem. This process is collaborative and often involves communication between non-co-located engineers. The development and communication of design solutions require engineers to form and share design rationale, that is, the argumentation in favour or against proposed designs.These aspects of the engineering design process have led to the development (Kunz & Rittel, 1970) and subsequent investigation (Buckingham Shum & Hammond, 1994;Fischer, Lemke, McCall, & Morch, 1991) of the issue-based information system (IBIS) method, a graph-based formalisation of the decisions made during a design process along with the reasons why they were made. The IBIS method envisions a decision-making process where problems (or issues) are given solutions (or answers) after a thorough debate involving technical, economical, life, environmental and safety considerations. It also provides means to actively develop, communicate and record the reasons (or arguments) in favour or against the options explored during the design process. Initially, IBIS was conceived purely as a conceptual information system and its first implementations were paper-based and totally operated by hand. However, over time several software tools supporting editing and visualisation of IBIS graphs have been developed, for example, Compendium, DRed and design Visual Understanding Environment (designVUE) (e.g. see Aurisicchio & Bracewell, 2013;Buckingham Shum et al., 2006). These IBIS-based tools,

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The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity.

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This work deals with the study of technologies aimed to upgrade the existing waste water treatment plants, paying attention to high process efficiencies and low costs. We verified the possibility to reach high N removal efficiencies in extended aeration activated sludge plants which are not equipped with specific denitrification steps. The experimented process is based on particular conditions, kept in the biological reactor, which allow simultaneous nitrification and denitrification, even without alternating (in time or in space) of anoxic and aerobic phases: aeration system is controlled by means of dissolved oxygen and redox potential measurements. Our research was carried out, for about three years, on a laboratory plant (V = 40 L) fed with synthetic waste water, a pilot scale plant (V = 1,400 L) fed with waste water coming from a real plant, and two full-scale plants (1,500-2,000 p.e.). The main advantages of the studied process are the following: high total N removal efficiencies (up to 90%) without the realization of new specific basins for the denitrification process; decreasing of operating costs (savings in Electric Energy consumption) due to the low oxygen concentration required in the biological reactor.