Quality of recycling: Urgent and undefined

Quality of recycling is a concept used by many authors in the scientific literature and the EU legislator. However, a clear definition of what is intended for quality of recycling and a framework for operationalising it is lacking. Most studies, while proposing indicators reflecting quality, leave the concept of quality largely undefined. Such lack of clarity is an obstacle to the conception of robust policies addressing recycling and circular economy. In this article, we review the available studies investigating on recycling quality, synthetize the approaches available and conclude suggesting a way forward for research to operationalise the definition to support circular economy policy measures and monitoring. Essentially, quality is not an on/off criterion. The definition of quality of recycling should consider that quality depends on technical characteristics of the recyclate, which determine if it is adequate (thus functional) for a certain end application or not. Furthermore, it should consider that the recyclate can be used in different end applications over different markets and that can be adequate for substitution of primary resources in certain applications, but less or not in others. At system-wide level, this results in a certain degree of virgin resource substitution. To this end, preserving functionality, i.e. minimising the recyclate loss of functions via functional recycling, is key. Drawing upon studies on waste management, life cycle assessment and resource dissipation, we link the concept of functionality to substitutability of virgin resources and broader suitability in the circular economy, striving to show the linkages between different perspectives.

Effect of a very low negative dietary cation-anion difference (DCAD) diet on plasma and urine metabolomics of prepartum Holstein cows

The objectives of this cross-sectional, nonintervention, observational study were to compare urine and blood parameters between cows consuming a positive dietary cation-anion difference (DCAD) diet [early dry cows, DCAD + 250 mEq/kg of dry matter (DM), n = 15] with the same cows consuming a negative DCAD diet (-220 mEq/kg of DM) 10 d after moving them from the early dry to the prepartum group. The most remarkable finding was that cows consuming the anionic diet had very low urine pH and very low base excess in blood, suggestive of uncompensated metabolic acidosis. Importantly, the metabolomics data revealed that only urine concentrations of essential and aromatic amino acids were decreased, and that concentrations of total nonessential amino acids and glucogenic amino acids were increased in plasma and reciprocally decreased in urine, suggesting that the cows fed anionic salts were attempting to meet a high glucose demand by mobilizing gluconeogenic amino acid reserves. Notably, the dietary anionic salts exerted marked effects on glycerophospholipids, with a reduction in most phosphatidylcholine containing diacyl (PC aa) and acyl-alkyl (PC ae) moieties in plasma and urine. Further characterization of these metabolomic profiles may lead to the development of novel biomarkers to identify cows susceptible to metabolic acidosis and other metabolic diseases.

Sustainability assessment of Construction and Demolition Waste management applied to an Italian case

Construction and Demolition Waste represents a priority stream for the European Union and has a large potential for closing the material circulation loop in line with the Circular Economy principles. The present study focuses on the socio-economic and environmental implications of the management of such waste in the Campania Region (Italy), with the aim of documenting the benefits of recycling actions and landfill avoidance. By using local primary data, and complementing them with data from literature and datasets, three scenarios have been investigated: i) Status Quo, i.e., a baseline scenario presenting the current management of Construction and Demolition Waste in the Region; ii) a Linear Economy scenario, considering the total flow disposed of in landfill and iii) a Best Practice scenario based on the implementation of selective demolition practices and increased recycling for the production of high-quality recycled aggregates. Special attention has been paid to the land use and socio-economic implications linked to the management of this flow, which are rarely considered. We quantify that, with the implementation of best practices, ca. 18 Mkg CO2 -eq. can be saved annually relative to the Status Quo alongside creating additional 1,000 jobs-eq. and incurring important benefits on land use. The results stress that the potential environmental and social benefits of selective demolition and best practices are significant, but the incurred economic costs may hinder their application and the resulting development of more circular economy actions in the construction sector, highlighting the need for incentives and tools to facilitate this transition.