• Energy Research

Abstract The rare earth elements (REEs) were classified as critical raw materials for Europe for their economic relevance and the supply risk. Currently, most of REE production is concentrated in the Chinese area and it is used for the production of many technologies including: fluorescent lamps, fluid catalytic cracking catalysts and permanent magnets. At the end of their life, these products can cause management problems, mainly due to the hazardous component presence. Nevertheless, this critical issue is combined with the significant content of REEs, which makes them a potential resource of secondary raw materials. In this regard, the literature reports many processes for the waste exploitation, but the effective sustainability is often neglected. In this context, the present paper took into account three processes, one for each mentioned waste, to assess both the environmental and the economic aspects. The obtained results were allocated on the basis of metals market price proving an advantage for most of the elements, compared to the primary production. Following the paper evaluation, the fulfillment of the circular economy approach could reduce up to 200 times the impact in the climate change category and up to 70 times the cost due to the REE mining.

Abstract One of the most significant effects of an earthquake is the production of a huge amount of waste. An incorrect management of the rubbles causes relevant environmental damages, economic losses and a psychological impact for the population. In this context, the present manuscript assesses different strategies of waste management, estimating the carbon footprint and the economic impact, in order to define the best choices. Overall, different management options can be applied, that have different costs and impacts on the environment: a temporary storage site could be used, rubbles can be treated through different technologies (either simple crushing or advanced refining), and the treatment can be carried out at different distances from the site of the event. The environmental impact assessment evidenced the importance of an in-situ pre-treatment of the rubbles and of an enhanced refining, addressed at the achievement of high quality inert. On the other hand, the economic analysis suggests that the best option is to transport everything to the treatment site, and to carry out a simple treatment of the rubbles. Consequently, our assessment resulted in conflicting conclusions, where an enhanced treatment of the rubbles is positive, from an environmental point of view, but negative, for the increase in the management costs. The economic criteria are currently pushing any decision taken by the emergency managers; however, the environmental load may have a long-term effect with even more significant economic consequences, and it cannot be neglected.

As it is now known, we have only one earth available for our life and it is our duty to preserve it [...]

End of life photovoltaic panels of different technologies (poly crystalline Si, amorphous Si, and CdTe) were treated mechanically in pilot scale by single shaft shredder minimizing the production of fine fractions below 0.4 mm (<18% weight). Grounded material was sieved giving: an intermediate fraction (0.4-1 mm) of directly recoverable glass (18% weight); a coarse fraction (which should be further treated for encapsulant removal), and fine fractions of low-value glass (18%), which can be treated by leaching for the removal of metal impurities. Encapsulant removal from coarse fraction was successfully performed by solvent treatment using cyclohexane at 50 °C for 1 h giving high-grade glass (52% weight), which can be reused for panel production. Experimental results of solvent treatment were compared with those from thermal treatment by economic analysis and Life Cycle Assessment, denoting in both cases the advantages of solvent treatment in recovering high-value glass.

AbstractBad choices in municipal waste (MW) management cause negative effects on sustainability. Evolving regulation has identified prevention and recycling as the best strategies; nevertheless, disposal in landfilling sites plays an essential role since a complete zero-waste scenario is not realistic, currently. Nowadays, policies require a preliminary waste stabilization to decrease the putrescible content. Therefore, mechanical biological treatment (MBT) has replaced the previous crushing, aimed at simple volume reduction. Literature has proved the effectiveness of MBT when MW collection system is ineffective. The present paper considered a facility in an area with a high-performance MW collection system. A long-term (1999–2019) on-site sampling allowed the comparison between two sites of the facility: the old site (before the MBT activation) and the new area, where the stabilized waste is disposed of. Monitoring of biogas, leachate (analyzed parameters: pH, BOD5, COD, ammonia-nitrogen) and odorous emissions was performed to verify the effect of the stabilization process. The considered long period and the on-site sampling support the relevance of the results, compared to the available literature, often referred to as laboratory scale. The results proved the relatively low benefit of stabilization at the considered facility, which cannot justify the energy consumption of MBT.

The construction and building field represents a key sector for the recent Circular Economy Action Plan (March 2020). Therefore, the production of low impact materials represents an essential step towards the implementation of a sustainable market. In this regard, the present paper focused on the production of painting wooden products for interior design. These industrial processes include an essential phase consisting of the reduction of odor emissions, which produce negative impacts on the environment and a persistent annoyance for the population close to the facilities. The main cause of the odor emissions in wood painting manufacturing is the production of volatile organic compounds (VOCs). In this context, the present research aimed to develop an innovative process able to combine the use of lower impact paints with a more efficient UV system for the abatement of the emissions.

The strong growth of the electrical and electronic equipment production combined with its short lifespan are causing the production of a significant amount of waste to treat. In particular, the present paper focuses on end-of-life liquid crystal displays (LCDs) for their significant content of valuable materials, like plastic, glass and metals that could be recovered after dismantling. In the recent literature, traditional LCD recycling processes are combined with innovative treatments, which allow to recover critical raw materials, such as indium. In this context, we have evaluated the environmental impact of four different strategies of end-of-life LCD management: the disposal in landfilling sites, the incineration, the traditional recycling treatment and an innovative process also addressed to the recovery of indium. The traditional recycling treatment resulted to be the best scenario for the environment. Indeed, a life cycle assessment study gave following environmental burdens (if negative they are credits): 18, 81, -68, -60kg CO2-equiv. and 0.08, 0.01, -0.25, -0.18mol H+-equiv., for the four scenarios in the categories of global warming and acidification, respectively. The limit of the variability of LCD composition was overcome including additional literature data in the study. In order to improve the innovative process sustainability, a system of water recirculation was optimized with a consequent impact decrease of 35% in the global warming category. Nevertheless, this action should be combined with an increase of indium concentration in the panel because the low metal content represents the bottleneck of the overall approach. In this regard, a sensitivity analysis showed that an increase of at least five times in indium concentration in the waste is needed to observe an advantage of the innovative vs the traditional recycling process, when the impact category of climate change is considered. As a whole, the life cycle assessment was confirmed as a key tool for the choice of the best option of WEEE management.

The agriculture sector produces significant amounts of organic residues and the choice of the management strategy of these flows affects the environmental sustainability of the sector. The scientific literature is rich with innovative processes for the production of bio-based products (BBP) from agriculture residues, aimed at the implementation of circular economy principles. Based on literature data, the present paper performed a life cycle assessment and assessed the environmental sustainability of five processes for the exploitation of rice and wheat straw, tomato pomace, and orange peel. The analysis identified as significant issues the high energy demand and the use of high impact organic solvent. The comparison of BBP with conventional products showed higher environmental loads for the innovative processes that used organic residues (except for rice straw case). The obtained results do not want to discourage the circular strategy in the agriculture sector, but rather to draw the attention of all stakeholders to the environmental sustainability aspects, focusing on the necessity to decrease the electricity demand and identify ecological agents to use in BBP manufacturing, in agreement with the most recent European policies.