1,721,092 research outputs found
SUSTAINABLE DEVELOPMENT GOALS AND CIRCULAR ECONOMY RELATIONSHIP ROLES IN EDUCATION AND INDUSTRY FOR WASTE COLLECTION IMPLEMENTATION
No full textInterest on circular economy (CE) is growing from many points of view. After discussing its relationship with the Sustainable Development Goals (SDGs), this article focuses on the role played in this frame by waste collection and specifically by education and industry. The importance of source separation emerged from the analysis. This is not limited to municipal solid waste only as special waste management can contribute to the circularity of the products
Special waste valorization and renewable energy generation under a circular economy: Which priorities?
Full text linkThe European Union regulation for emissions from waste incinerators had a significant evolution in the last 20 years. That allowed reaching a clear improvement in the environmental performances of the plants, synchronized with specific requests of compliance of the more and more stringent limits set at regulatory level. Today the main questions for the sector in Europe seem mostly related to the role of waste to energy plants in a scenario of circular economy and to the role of those plants in the generation of energy only in part renewable. It seems that the topic of the local environmental and health impact has become out to date in European Union. In spite of that, a big question remains on the suitability of the present regulation for the future of the sector, including co-incineration by the use of Secondary Recovered Fuel from waste as substitute of coal in cement works. The present article analyzes an aspect that should be a priority higher than the concept of circular economy and energy generation. Indeed, a question remains on the criticalities that could be present in the European Union for under-estimation of the role of heavy metals, in spite of the evolution of the regulation. If we look at the experience of the University of Trento (where the Author worked in various research projects since 2003) the last decade has been characterized by recurrent warnings from that University about the excessive simplification of the regulation in case of heavy metals. As an example, in case of waste incineration, a set of heavy metals are managed by summing their concentrations to be compared as sum to the regulation limit: no valorization of the specific knowledge on toxicity is made. In order to point out the consequences of this simplification, a few case-studies demonstrating a potential criticality on the role of CrVIare discussed. A control methodology integrating the present one is discussed in this article, to propose a solution suitable to avoid under-estimations of human exposure to heavy metals from incineration and co-incineration. This approach is particularly important when special waste is combusted as the composition of the input can present heavy metals concentrations higher than municipal solid waste
Selective collection as a pretreatment for indirect solid recovered fuel generation
No full textEffective selective collection (SC) has been increasing in many countries of the European Union. As a consequence the composition of residual municipal solid waste (RMSW) is changing not only because of economic development, but also due to the collection system. The input of RMSW treatment plants is thus not homogeneous. This paper analyses two case studies involving a total of five SC scenarios and their impact on the generation of solid recovered fuel (SRF) with/without bio-drying, post-treatment and packaging take back programs (TBPs). These case studies are based on two types of SC: kerbside and drop-off. The latest regulation on SRF classification is taken into account: energy content, Cl and Hg concentrations are assessed and discussed. The role of the respirometric index (RI) is also analyzed. Results show that when SC is highly efficient RMSW can be classified directly as SRF, but only if the introduction of RI does not set stringent respirometric targets. The role of packaging TBPs is important as the residual waste remaining after the packaging has been processed, can be valorized increasing the lower heating value (LHV) of the residual RMSW and minimizing the streams that should be landfilled. The source separation of food waste has a significant impact on the suitability of bio-drying: when the SC of food waste is very efficient, its percentage in the RMSW may be too low for effective bio-drying. © 2013 Elsevier Ltd
Optimizing the Methodology of Characterization of Municipal Solid Waste in EU under a Circular Economy Perspective
No full textThe methodology for the characterization of residual municipal solid waste (RMSW) is available since decades. Some modifications have been introduced in order to modernize it. Now, in order to take into account the targets of the circular economy, an additional effort must be made to be sure of generating the right information suitable for the optimization of municipal solid waste in that frame. In that perspective, the Authors present a few proposals in order to avoid mistakes and to deepen the reliability of the data generated during the analysis performed to classify the residual municipal solid waste in fractions. A new model of characterization is thus proposed, suitable for planning waste management in the frame of the circular economy principles
The sustainable city and air pollution
Full text linkThe present paper deals with the integrated approach typically adopted to improve the air quality in a European urbanized area. A case study is selected and analyzed in order to find out the viable criteria for the correct management of the problem, aimed at a sustainable city and the decrease of human health effects. The role of conventional and unconventional pollutants (e.g. PM10 and ultrafine particles) is discussed. The available measurement strategies are analyzed in order to point out the trend of the sector and the gap to be covered for guaranteeing a homogeneous protection of the territory (every citizen has the right to inhale air of the same quality). The importance of not limiting the analysis to the implementation of emission inventories is demonstrable through simple examples: indeed data of global balances can mislead decision makers; they must guarantee an acceptable human exposure that depends on the amount of pollutant that effectively reaches each inhabitant. Location criteria for urban planning are proposed to prevent unacceptable human exposure cases (e.g. kindergarten should not be authorized near an urban freeway; construction of street canyons should be avoided). Zooming out the urban area helps to demonstrate that the coordination among cities is compulsory. To this concern, the transport of air pollutants from region to region must be taken into account. Unconventional emerging solutions for improving the air quality in urban areas are presented and discussed in the paper together with cost-related viability aspects
Energy from municipal solid waste
Full text linkThis paper presents an overview of the solutions available for obtaining energy from municipal solid waste. Special waste is not taken into account because of its extreme variability of characteristics from region to region and from type to type. On the contrary, municipal solid waste shows aspects useful for a more homogeneous analysis of international interest concerning the exploitation of its energy content. The first part of this paper deals with the evolution of the interest towards energy recovery from municipal solid waste. The analysis is performed at an international level, but a zoom is presented referring to the European Union. The second part of the paper concerns the energy availability taking into account the dynamics of qualitative and quantitative composition of municipal solid waste. The third part analyses the role of selective collection in the frame of energy recovery. In this case it is pointed out how food waste selective collection can change the approach of biogas exploitation: from a landfill based concept (with sanitary landfill seen as a bioreactor) to a reactor based scenario (where the anaerobic digester allows for the collection of 100% of the biogas generated). The fourth section of the paper concerns the trend in residual municipal solid waste exploitation, taking into account the effects of the European Union directives on the energy recovery strategies and the role played by the Directive 1999/31/CE (a compulsory pre-treatment makes less interesting the option of landfilling, moving the energy exploitation of residual municipal solid waste towards thermal treatments). Finally, a section of this paper concerns a case study that offers a vision on how much anaerobic digestion and thermal treatments can support the energy demand of a citizen. © 2014 WIT Press
Opportunities for the energy sector from unconventional environmental analyses and sensors
Full text linkThe typical problems of air pollution to be faced with in many anthropized areas, even where the environment is protected by modern approaches, make it strategic the integration of conventional methodologies for air quality monitoring with unconventional ones proposed in the sector but not yet considered suitable to be official. By these integrated approaches, it is possible to identify single or multiple sources responsible of local air pollution (also in form of peaks of pollution). The additional information generated by unconventional sampling and/or sensors can be used by decision makers for setting strategies of reduction of the impact of specific sources, when these last ones are responsible of an unsustainable incidence in contributing to the local air pollution. A few case studies were selected and have been analysed to discuss about the advantages in integrating the conventional monitoring tools with other ones that are innovative (not alternative) but not official yet. The selected case studies belong to two categories: A) the first one concerns the identification of the role of a single source in contributing to the local air pollution, b) the second one concerns the assessment of the role of a sector in the local presence of air pollutants. The cases belong to the civil and the industrial sectors. Diffused and conveyed emissions are analysed depending on the case
Municipal solid waste selective collection and tourism
Full text linkThis paper concerns the interaction between tourism and the selective collection of municipal solid waste (MSW). Data for an Italian province are shown, zooming in on five municipalities characterised by the high presence of tourists along the year. Information on the selective collection organisation is presented (also based on the presence of eco-centers). The highest tourist months are in winter and summer and their effect is seen in the increase of the factions connected with the tourists meals and also the increase of residual MSW. The monthly peaks of waste generation are very high, but the final results in terms of selective collection efficiency seem to not be affected (being even higher than 80%, a value that is better than the one obtained at provincial scale). Also the presence of decentralised landfills did not discourage the source separation that changed significantly in about a decade. Moreover, the trend of tourists towards shorter periods of holiday does not affect selective collection; possibly because they are used to coming back to the same municipality, where they have already learned the local principles of source separation. © 2014 WIT Press
Potential environmental benefits of direct electric heating powered by waste-to-energy processes as a replacement of solid-fuel combustion in semi-rural and remote areas
No full textThe combustion of wood-based biomass for domestic heating, which is common in rural and mountainous regions of Europe, entails significant local impacts on air quality. Worse conditions occur in low-income countries where the use of coal in household stoves is a common practice. The present paper aims at demonstrating that the combination of waste-to-energy (WtE) plants (based on direct or indirect waste combustion technologies) and direct electric heating (DEH) would be beneficial to reduce air pollution and, meanwhile, optimize the local waste management. Specifically, a WtE plant powering a DEH network will be compared with two reference scenarios of domestic heating: the use of wood/pellet stoves and coal stoves. The results show that shifting to a DEH system, powered by the nearby WtE plant, would reduce the emissions of total suspended particles, NOx, CO, VOCs, dioxins, PAHs and heavy metals by >99%, 27%, 97%, 96%, 93%, 94% and 32%, respectively, with respect to the use of solid fuel in household stoves. In addition, the higher degree of atmospheric dispersion of the off-gas from the stack of the WtE plant is expected to further reduce the impacts in terms of air quality, as estimated by an approach based on the concept of dilution factors. The avoided transportation of waste to other waste facilities outside the region would reduce the greenhouse gas emissions with respect to coal combustion and biomass burning, by 63% and 3%, respectively. The integration of local WtE and DEH could be also “mild”, opening to scenarios that could improve the local air quality without renouncing totally to the habits of domestic wood combustion in mountainous regions. Mild-DEH could be designed to integrate the domestic use of wood with electrical heaters, reducing fuel use and air pollution
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