Promoting the reuse and recycling of building demolition materials

The demolition of constructed structures has earned a negative reputation for the construction industry due to the enormous amount of waste that is sent to landfills. Demolition waste reuse and recycling is, therefore, significant; it is a new and illustrative perspective on demolition waste management from the viewpoint of the building material lifecycle. It is discovered that demolition waste reuse and recycling plays important roles in value transformation for building material lifecycle, local economics,
sustainable environment and nature resource conservation. In this research article, the authors aim to pinpoint demolition waste management in the lifecycle of building materials, and to examine various economic and environmental aspects of demolition waste reuse and recycling. In addition, the barriers, limitations and solutions for improving the implementation of demolition waste reuse and recycling are discussed in the article.

Superplasticity and cavitation of recycled AZ31 magnesium alloy fabricated by solid recycling process

Superplastic behaviour of Mg-alloy AZ31 was investigated to clarify the possibility of its use for superplastic forming (SPF) and to accurately evaluate material characteristics under a biaxial stress by utilizing a multi-dome test. The material characteristics were evaluated under three different superplastic temperatures , 643, 673, and 703 K in order to determine the most suitable superplastic temperature. Finite Element Method (FEM) simulation of rectangular pan forming was carried out to predict the formability of the material into a complex shape. The superplastic material properties are used for the simulation of a rectangular pan. Finally, the simulation results are compared with the experimental results to determine the accuracy of the superplastic material characteristics. The experimental results revealed that the m values are greater than 0.3 under the three superplastic temperatures, which is indicative of superplasticity. The optimum superplastic temperature is 673 K, at which a maximum m value and no grain growth were observed. The results of the FEM simulation revealed that certain localized thinning occurred at the die entrance of the deformed rectangular pan due to the insufficient ductility of the material. The simulation results also showed that the optimum superplastic temperature of AZ31 is 673 K.

Public environmental consumerism : recycling behaviour and its impact on intentions to purchase green products

Recycling behaviour has been used as indicators of green behavior since research has indicated that there is a positive relationship between environmental concern and ecologically responsible behavior such as recycling. The objective of this study is to find out if there is a difference between recyclers and non-recyclers and heavy and light recyclers with respect to their willingness to pay more for green products despite the perception of green products being of a lower quality in comparison to alternative products. The answers to this will help us to better understand environmentally conscious consumerism of both groups of consumers i.e. the light and heavy recyclers. The results indicate that willingness to pay somewhat higher prices and accepting somewhat lower quality of green products appears to be, generally, independent of recycling and non-recycling, as well as heavy and light recycling behaviour. It also addresses the implications of these findings for business managers.

Polyhedral : recycling boundary ecologies

Foregrounding the extent to which 'place' remains resistant to the politics and poetics of 'network culture', this essay approaches place as a boundary ecology rather than as an instance of cultural invariance. It calls on readers to think about attempts to actively recycle cultural 'debris' or 'waste' through an ethics of passage instead of the kind of instrumentalist statics that prevents the development of an ontology of mobility. Con-tending that such a capacity to inhabit passage is compromised by the eschatological language used to communicate the implications of environmental disaster, as well as by languages of consultation that (con-ceptually) empty place of any creative power to incubate alternatives – events, modes of relation –, the essay stresses the mythopoetic techniques that produce places as knots or nodal points within a network of pas-sage. The designer's task is to create the hinge mechanisms that render such boundary ecologies inhabitable imaginatively, and by materialising the nexus between creativity and change to alter our position vis-a-vis our ethical responsibilities as citizens of a shared biosphere.

Solid state recycling of 5083 Al alloy by hot extrusion

The machined chips of 5083 Al alloy were recycled by hot extrusion at 723 K with an extrusion ratio of 44:1 in air. Corrosion and mechanical properties of the recycled specimens have been compared with those of a virgin extrusion which was processed from the ingot block. As a result of salt immersion tests, mass loss of the recycled specimen was not less than twice of that of the virgin extrusion. The deterioration in corrosion properties for the recycled specimen was attributed to the excessive contamination of Fe which promoted galvanic corrosion. As a result of tensile tests, the recycled specimen exhibited a good combination of high strength and high elongation to failure at room temperature. The excellent mechanical properties for the recycled specimen were attributed to the refined microstructure. However, the elongation to failure of the recycled specimen at elevated temperatures more than 573 K was lower than that of the virgin extrusion. The contamination of oxide particles is likely to be responsible for the lower elongation in the solid recycled specimen.

Reductions in nutrient discharge from aquaculture through recycling of water utilising floating media and activated carbon filtration

Nutrient discharge into coastal areas, such as the Great Barrier Reef can result in the degradation of coastal ecosystems. For example, excess nitrogen and phosphorus can damage corals through inducing algal bloom and subsequent shading. Excessive phosphorus can further weaken coral skeletons making them susceptible to damage. Land based industries such as aquaculture can contribute to such problems. This study set out to develop a system whereby water from aquaculture can be constantly reused resulting in minimized waste discharge. A three-stage filtration system utilizing floating media and activated carbon was designed to harness bacterial processes that could reduce both particulate and dissolved compounds to the extent whereby approximately 100% reuse of the wastewater became possible. This involved efficient and effective particulate and biological removal mechanisms in both aerobic and anaerobic zones of the filtration system. This design reduced dissolved nitrogen levels by up to 70% and maintained low phosphorus levels, which allowed the reuse of water for the successful culture of barramundi with a survival rate of 97% over 25 days. This pilot scale study demonstrated the potential of reusing aquaculture wastewater from the viewpoint of reducing nutrient input into coastal environments. Future research will refine these processes and assess the performance of the system at several commercial scale applications.

Sustainable aquaculture through water recycling

The discharge of nutrient rich effluent from aquaculture systems into coastal waters is cause for concern. Direct filtration of aquaculture wastewater, using floating medium and sand with in line flocculation, and biological filtration using activated carbon, has the potential to improve water quality for recycling within aquaculture systems. This study looked at the performance of laboratory scale dual media and activated carbon filters in suspended solids and nutrient removal in the treatment of aquaculture wastewater. The dual media filter, with flocculant FeCl3 of 9mg/L, functioned best at a velocity of 7mJh with low headloss, and good turbidity and phosphorus removal (80% and 53% respectively). The activated carbon filter removed ammonia (84%) and nitrite (71 %) in the process of nitrification with a five-hour hydraulic retention time. This paper reports preliminary results from a longer term sustainable aquaculture project.

Found footage: recycling historic material a-historically

The digital has speeded up multi-platform image delivery, to impose sampling and collagic strategies into the way we process information. This is a trauma inducing situation. During an earlier period of technological change reading the moving landscape similarly overwhelmed the early train traveller. Wolfgang Schivelbusch noted that ‘The inability to acquire a mode of perception adequate to technological travel crossed all political, ideological and aesthetic lines.’ (1983) New perceptual strategies had to be developed that contextualized the blur and the streak produced by looking out the train window without overwhelming the viewer. Utilizing Chris Brewin’s (2001) model of two parallel memory systems, this paper argues that, as another round of unprecedented technological change impacts on our senses, another ‘re-alignment’ of the senses is required. Chris Brewin’s (2001) model of two parallel memory systems, of Verbally Accessible Memory (VAM) and Situational Accessible Memory (SAM), suggests that the current information explosion requires a greater emphasis on the SAM system for processing information and critical thinking. Processed through the amygdala, SAM is implicit, situationally triggered, information intensive and conveys no sense of time. Found footage films, like those of Martin Arnold and Peter Tscherkassky that cut up, layer, repeat and recycle historic imagery perform the sampling and collagic strategies that characterize this SAM memory system to demonstrate a more visually based mode of critical thinking.

Recycling textiles : The use of ionic liquids in the separation of cotton polyester blends

Textiles are commonly made from intimate blends of polyester and cotton, which makes recycling very difficult. We report for the first time the use of ionic liquid in the separation of polyester cotton blends. By selective dissolution of the cotton component, the polyester component can be separated and recovered in high yield. This finding presents an environmentally benign approach to recycling textile waste. © 2014 The Royal Society of Chemistry.