In this paper, a circular-economy framework is applied to the prefabricated building sector to explore the environmental advantages of prefabrication in terms of reduction, reusability, adaptability, and recyclability of its components. A qualitative approach is used to revisit the design, construction, and demolition stages of prefabricated buildings; in so doing, the circular-economy framework is applied to foster circular prefabricated modi operandi. Prefabrication of buildings can be divided into four entities: elements and components, panels (or non-volumetric elements), volumetric, and entire modules. Through an analysis of published research on how the circular economy can be applied to different industry sectors and production processes, seven strategies emerged, each of which revealed the potential of improving the circular economy of buildings. The first strategy is reduction of waste through a lean production chain. By reusing the waste, the second strategy investigates the use of by-products in the production of new components. The third strategy focuses on the reuse of replacement parts and components. The fourth strategy is based on design toward adaptability, respectively focusing on reusability of components and adapting components for a second use with a different purpose. Similarly, the fifth strategy considers the implications of designing for disassembly with Building Information Modeling so as to improve the end-of-life deconstruction phase. The sixth strategy focuses on design with attention to recyclability of used material. Finally, the seventh strategy considers the use of tracking technologies with embedded information on components’ geometric and mechanic characteristics as well as their location and life cycle to enable second use after deconstruction. It is demonstrated that prefabricated buildings are key to material savings, waste reduction, reuse of components, and various other forms of optimization for the construction sector. By adopting the identified strategies in prefabricated buildings, a circular economy could be implemented within the construction industry. Finally, seven guidelines were distilled from the review and linked to the identified strategies. Owing to their degree of adaptability and capacity of being disassembled, prefabricated buildings would allow waste reduction and facilitate a second life of components.
7 August 2000 in Journal of Environmental Monitoring
A new sampling system has been developed for the measurement of time-averaged concentrations of organic micropollutants in aquatic environments. The system is based on the diffusion of targeted organic compounds through a rate-limiting membrane and the subsequent accumulation of these species in a bound, hydrophobic, solid-phase material. It provides a novel and robust solution to the problem of monitoring in situations where large temporal fluctuations in pollutant levels may occur. Accumulation rates are regulated by choice of diffusion-limiting membrane and bound solid-phase material and have been found to be dependent on the physico-chemical properties of individual target analytes. Two separate prototype systems are described: one suitable for the sampling of non-polar organic species with log octanol/water partition coefficient (log P) values greater than 4, the other for more polar species with log P values between 2 and 4. Both systems use the same solid-phase material (47 mm C18 Empore™ disk) as a receiving phase but are fitted with different rate-limiting membrane materials (polysulfone for the polar and polyethylene for the non-polar analytes). The two systems complement each other and together can be used for sampling a wider range of organic analytes than generally possible using current passive sampling techniques. Calibration data are presented for both devices. In each case, linear uptake kinetics were sustained, under constant conditions, for deployment periods of between 1 and 9 days. The effects of water temperature and turbulence on sampling rates have been quantitatively assessed. The performance of the system was further investigated by means of field exposures for one and two weeks in marine environments where calibrated samplers were used to determine the time-averaged concentrations of the polar biocides diuron and irgarol 1051. The quantitative results obtained using the passive sampler were compared with those obtained using spot sampling.
1 September 2002 in Science of The Total Environment