Business models for the reuse of construction and demolition waste.

The construction sector is the largest contributor to waste in Europe. Approximately one-third of all waste originates from construction and demolition. In Europe, most construction and demolition waste (CDW) is recycled as backfilling and only limited amounts of construction materials are reused for their original purpose. There is a current policy push by the European Commission (EC), as well as several EU member states, focused on lifting waste up the European waste hierarchy from recycling to reuse to help preserve resources and reduce the environmental impacts of CDW, which is considered a priority waste stream. This article explores the potential and the barriers to the increased reuse of CDW and describes several business models for reuse based around the intersection between public authorities, waste companies and private companies involved in the construction and demolition sector. The article is empirically based on a study of various reuse schemes operated by waste companies, municipalities and private waste operators in Denmark. Using a mixed-methods approach, in which survey methods are combined with company visits and qualitative interviews, the article analyzes the potential and the barriers to the creation of direct reuse schemes for CDW. Based on the findings from these, four generic business models for the direct reuse and recycling of CDW are synthesized specifically targeting the CDW fractions that are waste managed at public recycling stations. Finally, the article discusses how market conditions, environmental issues and quality can influence emerging reuse schemes.

A review of the plastic value chain from a circular economy perspective.

Although plastic is one of the most commonly used materials in our everyday life, the current linear economy ('produce, use and dispose') engenders high risks to human health in relation to greenhouse gas (GHG) emissions and environmental pollution. As a response to these challenges, the circular plastic economy is gaining momentum, where the goal is to reduce, reuse and recycle all plastic. The transition to the circular economy should be made across the entire plastics value chain in order to ensure circular design, production, use and waste management. This study examines the current scientific literature in relation to the entire value chain of plastics. This aim of the article is to provide an overview of the existing research (and highlight research gaps) associated with the transition of plastic use to a circular model. The literature was divided into the following categories: 1) design; 2) production; 3) use; 4) end-of-life; and 5) value chain. A high proportion of the literature was found to address the end-of-life phase, suggesting that the other phases are currently neglected. The results have implications that are applicable to multiple phases; in particular, contamination of waste streams and composite materials places significant limitations on the opportunity to recycle and reuse plastic in new products. This calls for changes in the whole value chain, and for trans-sectorial collaboration to ensure systemic transparency. Therefore, future research should take a holistic approach to the transition to circular through careful mapping of implications, stakeholder involvement and collaboration.

Linking climate change mitigation and coastal eutrophication management through biogas technology: Evidence from a new Danish bioenergy concept.

The interest in sustainable bioenergy solutions has gained great importance in Europe due to the need to reduce GHG emissions and to meet environmental policy targets, not least for the protection of groundwater and surface water quality. In the Municipality of Solrød in Denmark, a novel bioenergy concept for anaerobic co-digestion of food industry residues, manure and beach-cast seaweed has been developed and tested in order to quantify the potential for synergies between climate change mitigation and coastal eutrophication management in the Køge Bay catchment. The biogas plant, currently under construction, was designed to handle an annual input of up to 200,000 t of biomass based on four main fractions: pectin wastes, carrageenan wastes, manure and beach-cast seaweed. This paper describes how this bioenergy concept can contribute to strengthening the linkages between climate change mitigation strategies and Water Framework Directive (WFD) action planning. Our assessments of the projected biogas plant indicate an annual reduction of GHG emissions of approx. 40,000 t CO2 equivalents, corresponding to approx. 1/3 of current total GHG emissions in the Municipality of Solrød. In addition, nitrogen and phosphorous loads to Køge Bay are estimated to be reduced by approx. 63 t yr.(-1) and 9 tyr.(-1), respectively, contributing to the achievement of more than 70% of the nutrient reduction target set for Køge Bay in the first WFD river basin management plan. This study shows that anaerobic co-digestion of the specific food industry residues, pig manure and beach-cast seaweed is feasible and that there is a very significant, cost-effective GHG and nutrient loading mitigation potential for this bioenergy concept. Our research demonstrates how an integrated planning process where considerations about the total environment are integrated into the design and decision processes can support the development of this kind of holistic bioenergy solutions.