While attention on the importance of closing materials loops for achieving circular economy (CE) is raging, the technicalities of doing so are often neglected or difficult to overcome. These technicalities determine the ability of materials, components and products (MCPs) to be properly recovered and redistributed for reuse, recycling or recovery, given their remaining functionality, described here as the remaining properties and characteristics of MCPs. The different properties of MCPs make them useful for various functions and purposes. A transition, therefore, towards a CE would require the utmost exploitation of the remaining functionality of MCPs; ideally, enabling recirculation of them back in the economy. At present, this is difficult to succeed. This short communication article explains how the remaining functionality of MCPs, defined here as quality, is perceived at different stages of the supply chain, focusing specifically on plastic packaging, and how this affects their potential recycling. It then outlines the opportunities and constraints posed by some of the interventions that are currently introduced into the plastic packaging system, aimed at improving plastic materials circularity. Finally, the article underpins the need for research that integrates systemic thinking, with technological innovations and policy reforms at all stages of the supply chain, to promote sustainable practices become established.
Highlights Plastic waste recycling is currently facing a wide range of bottlenecks. There is a need for a sufficient collection, sorting and recycling infrastructure. Mechanical and aesthetic properties of the recyclates should be carefully considered. Potential collaboration within industries may be proved a fruitful route. A combined and aligned effort by all involved parties is a necessity.
a b s t r a c tThe transition to a circular economy, where the value of resources is preserved in the technosphere, must be supported by policies and operational decision-making based on evidence. Existing methods used to provide this evidence (e.g. LCA, LCSA, CBA) are not robust enough to adequately address the creation and dissipation of systemic and multidimensional value that spans the social, environmental, economic and technical domains. This study proposes a novel, conceptual approach that seeks to assess how complex value is created, destroyed and distributed in resource recovery from waste systems. This approach expands beyond conventional methods of estimating value. It combines scientific and engineering methods with a socio-political narrative grounded in the systems of provision (sop) approach, and provides a comprehensive, analytical framework for making the transition to a resource-efficient future. This framework has the potential to connect bottom-up and top-down approaches in assessing resource recovery from waste systems, and address systemic challenges through transparency and flexibility, while accounting for the dynamic and non-linear nature of commodities flow and infrastructure provision in the overall system. This creates the pathway towards circular economy, and lays the foundations for future advances in computational and assessment methodologies in the field of RRfW. Crown
Landfilling is one of the most common waste management methods employed in all countries alike, irrespective of their developmental status. The most commonly used types of landfills are (a) municipal solid waste landfill, (b) industrial waste landfill, and (c) hazardous waste landfill. There is, also, an emerging landfill type called “green waste landfill” that is, occasionally, being used. Most landfills, including those discussed in this review article, are controlled and engineered establishments, wherein the waste ought to abide with certain regulations regarding their quality and quantity. However, illegal and uncontrolled “landfills” (mostly known as open dumpsites) are, unfortunately, prevalent in many developing countries. Due to the widespread use of landfilling, even as of today, it is imperative to examine any environmental- and/or health-related issues that have emerged. The present study seeks to determine the environmental pollution and health effects associated with waste landfilling by adopting a desk review design. It is revealed that landfilling is associated with various environmental pollution problems, namely, (a) underground water pollution due to the leaching of organic, inorganic, and various other substances of concern (SoC) contained in the waste, (b) air pollution due to suspension of particles, (c) odor pollution from the deposition of municipal solid waste (MSW), and (d) even marine pollution from any potential run-offs. Furthermore, health impacts may occur through the pollution of the underground water and the emissions of gases, leading to carcinogenic and non-carcinogenic effects of the exposed population living in their vicinity.
Graphical abstract
Circular economy (CE) is extensively discussed around the globe. Presently, discussions are mostly concerned with the importance of achieving CE and the benefits associated therewith, with the various barriers surrounding its implementation being less debated. Understanding the context in which circularity can flourish is a prerequisite in building the capabilities to deal with the multi-faceted challenges that currently hamper progress in closing the material, component and product loops. In this study, we discuss the importance of systems thinking in understanding the way resource recovery systems operate, and in promoting deep transformational change. We suggest that transformational change needs to go beyond closing materials, components and products (MCPs) loops, and promote sustainability in the way resources are exploited, used and managed throughout the system. By adopting a system of systems approach, we postulate that there are five interconnected sub-systems that need to be considered for supporting transitions to CE, namely, resource flows and provisioning service; governance, regulatory framework and political landscape; business activities and the marker; infrastructure and innovation; and user practices. This holistic approach provides a useful means to cutting through systemic complexity, and focuses on the dynamics between processes, values and actors in the value chain, and their dependence on cultural, spatial and temporal characteristics. We conclude that a systems-based approach can build up the capabilities required to identify and understand persistent linear trends and, in turn, support forward-thinking and time investment in enabling sustainable transitions. This, in turn, can help to align priorities and transform our current practices, speeding up the process of closing the MCP loops in a sustainable manner.
Eight different surface sediment samples (K1-K8) were collected from two separate areas of Lake Koumoundourou and two samples (E1 and E2) from one area of Elefsis Bay, Athens, Greece. The level of pollution attributed to heavy metals was evaluated using several pollution indicators. Degree of Contamination, Modified Contamination Degree and Geoaccumulation Indexes were applied in order to determine and assess the anthropogenic contribution of the selected six elements (Cr, Ni, Cu, Zn, As and Pb). Moreover, the adverse effects of the sediments to aquatic organisms, from both heavy metals and polycyclic aromatic hydrocarbons (PAHs), were determined by using Sediment Quality Guidelines. The results indicated that Lake Koumoundourou is contaminated with heavy metals in a moderate degree and almost 50 % of the sediments are associated with frequent observation of adverse effects, when it comes to Ni and occasional observation of adverse effects, when it comes to Cu, Zn and Pb. As far as PAHs are concerned, around 60 % of the samples can be occasionally associated to toxic biological effects according to the effect-range classification for phenanthrene, benzo(a)anthracene, chrysene and pyrene. Finally, samples taken from the north side of the lake are more contaminated with PAHs than the ones taken from the east side probably due to the existence of the water barrier which acts as a reservoir of PAHs.
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