Origins of the Concept of Circular Economy and its Evolution

The first concepts connected with the material circularity have been introduced through the terms of Industrial Symbiosis and Industrial Ecology since the 1940s. In 1947 Renner, G. included in his works the term of ‘reuse – exchange’ as processes by which waste or by-products of an industry or industrial processes become the raw materials for another one (exchange). In 1966, Economy in Washington – with the paper ‘The Economics of the Coming Spaceship Earth’ presented the idea of a circular loop for the materials, considering open and closed systems. Moreover, in the 1970s, Stahel, W. R. introduced the concept with the expression ‘cradle-to-cradle’ in opposition with ‘cradle-to grave’. As a consequence of the environmental revolution, the industrial ecology gained more and more importance. In the 1980s, Frosh, R. A. proposed an analogy of natural ecosystems, for the eco-industrial ones: in addition to reducing the production of wastes, they should maximize the efficient use of residue materials and end-of-life products, as an input for other production processes. In 1994, Pauli, G. in ‘Zero Emissions Research and Initiatives’ divided the economic models in three: red, green and blue economy. Later, Ayres went ahead using the metaphor of the biosphere (ecology) – technosphere (economy), followed by Biomimicry of Benyus, thanks to the ‘Spiral of Life’. At the end of the 19th and the beginning of the 20th centuries, the Linear Economy based on the terms take, make, consume, throw away was introduced. Its development is connected with the technological innovations encouraged by the growing scientific development increased productivity and promoted the progress of the linear economy. The Circular Economy, was introduced in 2015 by the European Union, and its aim is connected with the concept of: a) more efficient and sustainable use of resources; b) new integrated model of production, distribution and consumption

Public attitude towards nuclear and renewable energy as a factor of their development in a circular economy frame: two case studies

5siThe energy sector is one of the most important sectors of the economy and one of the polluters of the environment. Therefore, in order to achieve the Sustainable Development Goals and the climate goal stated in the Paris Agreement, many countries need to carry out a full-scale eco-modernization of the energy sector and develop green energy. Nuclear and renewable energy may become key areas of global energy development in the near future, in agreement also with Circular economy concepts, but public opinion (and other controversial visions/aspects) is one of the barriers to their development. The purpose of this study is to analyze the relationship between attitudes towards nuclear and renewable energy in two countries: EU and non-EU, considering the level of their development. The authors conducted a survey among residents regarding their attitude towards nuclear and renewable energy, as well as their attitude to the present energy policy. The cluster analysis technique was used to analyze the results. The obtained results confirmed the dependence between the level of development of nuclear and renewable energy and the public attitude towards it. The authors identified the public attitude as one of the key factors in the development of energy and the achievement of environmental and social sustainability.openopenKaraeva, Anzhelika; Magaril, Elena; Torretta, Vincenzo; Viotti, Paolo; Rada, Elena CristinaKaraeva, Anzhelika; Magaril, Elena; Torretta, Vincenzo; Viotti, Paolo; Rada, Elena Cristin

IMPORTANCE OF COMPREHENSIVE HEALTH RISK ASSESSMENT PROCEDURES FOR MODERN WASTE-TO-ENERGY FACILITIES IN COMPLEX GEOGRAPHICAL CONTEXTS ORIENTED TO CIRCULAR ECONOMY

Although circular economy (CE) principles set material circularity, resource efficiency and waste recycling as priority targets to guarantee the sustainable development of future generations, the thermochemical valorisation of municipal solid waste (MSW) still plays a fundamental role in the transition towards the final CE targets. As a matter of fact, the waste-to-energy (WtE) sector allows recovering energy from waste, reducing the pressure on MSW landfills and their related potential environmental impacts; however, recovering material for further uses is not excluded in WtE options. Significant improvements have been achieved in the air pollution control of exhaust gases from direct and indirect MSW combustion during the last decades. The efforts focussed on reducing dioxin emissions especially, and this has let other substances emerge as priority pollutants (e.g., heavy metals). In addition, the location of WtE facilities in certain geographical contexts is still potentially critical from the point of view of human exposure and the related health risk; moreover, the public acceptance of WtE plants is still limited, in spite of their recent role in fighting SARS-CoV-2 risks from waste management. The purpose of the present paper is to underline the importance of implementing correct and complete health risk assessment procedures tailored to the exposed population living in the area of influence of a WtE plant. The paper will present two case studies regarding the projects of two WtE plants in a mountainous region, highlighting the critical issues that arose during the environmental impact assessment procedures. The paper will finally suggest possible options to improve the health risk assessment procedure and alternative measures to reduce the expected impacts of the WtE sector on the environment and human exposure

Potential of bio-drying applied to exhausted grape marc

In the present work, experimentation was carried out to study the behavior of exhausted grape marc during the bio-drying process. This process was chosen as an alternative to the typical grape marc thermal drying approach. The aim was to reduce the moisture level thanks to the biological exothermal reactions, and to increase the energy content in the biodried grape marc. The target was the generation of a product interesting for energy options. For the development of the research, a biological pilot reactor and a respirometric apparatus were used. Results demonstrated that bio-drying can decrease the water content saving the original energy content. The final material could be assumed like a solid recovered fuel, class 5:1:1 with a very low potential rate of microbial self-heating

Approaching sustainability and circularity along waste management systems in universities: an overview and proposal of good practices

In recent years, the importance of sustainability and circularity in waste management systems has become increasingly evident. As the world grapples with the environmental consequences of excessive waste generation, it has become crucial to find innovative and sustainable solutions. Universities, as centres of knowledge and research, play a vital role in achieving sustainability and circularity in waste management. The key contribution of this study is to provide: 1) a systematic review of the existing literature concerning sustainable waste management systems (SWMS) implemented in universities; 2) an analysis of the studies presented in this paper identifying applicable approaches and sustainable practices to provide novel guidelines by including waste management system in a circular and sustainable model within universities. Through research, collaboration, education, implementation of sustainable practices, and support for entrepreneurship, universities can strongly contribute to the development and implementation of sustainable waste management practices. As the world continues to face the challenges of waste generation, universities will continue to be at the forefront of finding innovative, sustainable, and circular solutions

Critical analysis of the integration of residual municipal solid waste incineration and selective collection in two Italian tourist areas

Municipal solid waste management is not only a contemporary problem, but also an issue at world level. In detail, the tourist areas are more difficult to be managed. The dynamics of municipal solid waste production in tourist areas is affected by the addition of a significant amount of population equivalent during a few months. Consequences are seen in terms of the amount of municipal solid waste to be managed, but also on the quality of selective collection. In this article two case studies are analyzed in order to point out some strategies useful for a correct management of this problem, also taking into account the interactions with the sector of waste-to-energy. The case studies concern a tourist area in the north of Italy and another area in the south. Peak production is clearly visible during the year. Selective collection variations demonstrate that the tourists' behavior is not adequate to get the same results as with the resident population. © The Author(s) 2014

Local Actions for Reducing Global Greenhouse Gas Footprint: 10 Years of Covenant of Mayors Initiative

Covenant of Mayor was launched in 2008 as a voluntary initiative for local administrations that intend to adopt a plan of interventions concerning greenhouse gas mitigations, achieving and exceeding the EU climate and energy targets. In its first decade of activity, Covenant of Mayors has become the world\u2019s largest initiative based on actions of energy saving and local climate mitigation, involving 250+ million inhabitants and 7700+ signatories in more than 50 countries worldwide, under the denomination of Global Covenant of Mayors for Climate and Energy. Globally, a total 5996 municipalities subscribed to the above-mentioned agreement in the first decade, in addition to 1743 progress plans and a wide database of indications regarding successful actions of Greenhouse Gas footprint mitigation at a European scale. This work reports on the global statistics of the initiative in the period 2008-2017 and the geographical location of the signatories within the territory of the European Union, highlighting limits and challenges of the initiative

Microplastics removal in wastewater treatment plants: A review of the different approaches to limit their release in the environment

In last 10 years, the interest about the presence of microplastics (MPs) in the environment has strongly grown. Wastewaters function as a carrier for MPs contamination from source to the aquatic environment, so the knowledge of the fate of this emerging contaminant in wastewater treatment plants (WWTPs) is a priority. This work aims to review the presence of MPs in the influent wastewater (WW) and the effectiveness of the treatments of conventional WWTPs. Moreover, the negative impacts of MPs on the management of the processes have been also discussed. The work also focuses on the possible approaches to tackle MPs contamination enhancing the effectiveness of the WWTPs. Based on literature results, despite WWTPs are not designed for MPs removal from WW, they can effectively remove the MPs (up to 99 % in some references). Nevertheless, they normally act as “hotspots” of MPs contamination considering the remaining concentration of MPs in WWTPs’ effluents can be several orders of magnitude higher than receiving waters. Moreover, MPs removed from WW are concentrated in sewage sludge (potentially >65 % of MPs entering the WWTP) posing a concern in case of the potential reuse as a soil improver. This work aims to present a paradigm shift intending WWTPs as key barriers for environmental protection. Approaches for increasing effectiveness against MPs have been discussed in order to define the optimal point(s) of the WWTP in which these technologies should be located. The need of a future legislation about MPs in water and sludge is discussed

Carbon Footprint and Energy Recovery Potential of Primary Wastewater Treatment in Decentralized Areas: A Critical Review on Septic and Imhoff Tanks

The present work is a critical review on the carbon footprint and energy recovery potential of septic and Imhoff tanks for primary wastewater treatment. From an online search of research papers, a lack of up-to-date research about gas emissions from Imhoff tanks emerged. Additionally, available literature data should be extended to incorporate the effect of seasonal variations, which may be relevant due to the fact that both systems work under environmental conditions. The literature generally agrees on the positive effect of temperature increase on biogas and methane production from both septic and Imhoff tanks. Additionally, sludge withdrawal is an important operational feature for gas production in these reactors. More recently, the application of electrochemical technologies and the installation of photovoltaic modules have been studied to enhance the sustainability of these decentralized solutions; in addition, sludge pretreatment has been investigated to raise the obtainable methane yields due to limited sludge biodegradability. Further research is needed to assess the effective sustainability of biogas collection and valorization from existing septic and Imhoff tanks, considering the limited biogas generation and the implementation of these systems in decentralized wastewater treatment scenarios (rural or mountain areas). Contrary to the intensive research on greenhouse gas mitigation strategies applied to centralized systems, solutions specifically designed for gas emission mitigations from septic and Imhoff tanks have not attracted the same scientific interest up to now. More generally, given the widespread application of these two options and their potential significant contribution to the overall carbon footprint of wastewater treatment technologies, much more research must be performed in the future both on the quantification of gas production and on the applicable strategies to reduce their carbon footprint