Innovating at the food, water, and energy interface.

Food, energy, and water (FEW) systems are inexorably linked. Earth's changing climate and increasing competition for finite land resources are creating and amplifying challenges at the FEW nexus. Managing FEW systems to mitigate these negative impacts and stresses is a pressing policy issue. The FEW interface is often managed as three independent systems, missing disruptive opportunities for streamlined integrated management. We contend that existing technologies can be reframed and emerging technologies can be harnessed for integrated FEW management, changing the way that each resource system operates within the broader system. We discuss solutions to three main challenges to integrating FEW system management: resolving spatiotemporal disconnections over multiple scales; closing resource loops; and creating actionable information. Sustainable resource management is critical for humanity, as well as for functioning trade systems and ecological health. Embracing integrated management in FEW systems would enable policy makers and managers to more efficiently and effectively secure critical resource systems in the face of global change.

Output-oriented analysis of the wet mechanical processing of polyolefin-rich waste for feedstock recycling.

In recent years, an increasing number of studies have revealed that plastics and their components (e.g. plasticisers) pose an environmental risk. However, it is hard to imagine how our industrialised society could do without these materials, since the fields of application are manifold. One possible approach to tackle this mounting problem is the implementation of a comprehensive and well-functioning collection and recycling system. An international comparison shows that only a small proportion of the total plastics in circulation is collected and recycled. The investigations conducted under the present research project, 'Plastic Reborn', focused on both identification and analysis of the discharge paths of polyolefin-rich waste streams, under the Austrian waste management system. Another objective was determining the utilisation potential of the output fractions of these polyolefin-rich waste streams, generated from a wet mechanical processing pilot plant. Experiments have shown that the polyolefins are successfully separated from the waste streams and that a total polyolefin potential of 429,000 t y-1 remains unexploited in the Austrian waste management system. Thus, these separated plastic fractions can make a significant contribution to the implementation of the European Circular Economy Directive. The residual fractions meet the legal and company-specific requirements for their use as solid recovered fuels in co-combustion plants.

An overview of the challenges and trade-offs in closing the loop of post-consumer plastic waste (PCPW): Focus on recycling.

Recycling of post-consumer plastic waste (PCPW) is increasingly promoted as the means to achieving circular economy (CE). It converts plastic waste into a secondary material that can be fed back into the system, for use in the same or new components and products, with similar or lower functionality; hence "closing the loop". Up until today, research on examining the environmental impacts, economic implications and technicalities of plastic waste recycling deals with one particular aspect, or stage on the plastic value chain, lacking coherence and structure. To move this research forward, understanding the challenges and trade-offs in scaling up plastic waste recycling is necessary. Here, we bring together existing literature on the multi-faceted aspects of closing the plastic loop, critically debating on the multi-stakeholder endeavours of promoting circularity in the plastics value chain. We present an overview of how the design, production, collection and sorting of PCPW present challenges for plastic waste recycling, which in turn result to a number of trade-offs. We explain that the evaluation of the multi-dimensional implications of trade-offs arising from the PCPW recycling, is essential in measuring the long-term sustainability of resource recovery from waste systems. This work scrutinises the sustainability of closing the plastic waste loops and sets a future research agenda.