Search Results (6,514)

Biodegradable organic waste offers significant opportunities for resource recovery within the frame of the circular economy. In this work, the effects of carbon-encapsulated iron nanoparticles and ozone pre-treatments in the mesophilic methanogenic stage of a temperature-phased an-aerobic digestion have been studied using biochemical methanogenic potential (BMP) tests and modeling simulation. To do that, digestates from a pre-treated thermophilic acidogenic reactor that co-digested sludge and wine vinasse were used. The addition of nanoparticles favored the removal of particulate matter, which increased by 9% and 6% in terms of total solids and volatile solids, respectively. When combined with ozone pre-treatment, these increases were 27% and 24%, respectively, demonstrating enhanced AD efficiency. The dose of iron nanoparticles encapsulated in carbon did not result in a statistically significant increase in methane production when sludge and vinasse were used as feedstock. The combination of nanoparticles with the ozone pre-treatment significantly improved the methanogenic phase of the second stage, increasing the methane production yield by 22% and reducing the lag phase from 10 days to 3 days, according to the modified Gompertz model. Full article

Prickly pear (Opuntia ficus indica L.) could be used in rabbit nutrition in compliance with circular economy principles, global warming issues, and reduction of production costs. This study aims to evaluate the effects of dietary incorporation of prickly pear seed cake (PPSC) on growth, physiological, and histometric parameters in rabbits. A total of 105 rabbits were divided into three experimental groups (n = 35) and fed different diets: a commercial feed (C group), the same feed with alfalfa replaced by PPSC at 10% (10PP group), and at 20% (20PP group). They were group-housed in cages with 5 animals per cage from weaning until slaughtering. While body weights and weight gains were similar in all groups, the coefficients of nutrient digestibility of dry matter, fibers, and ashes, as well as the characteristics of intestinal villi, were improved in the 10PP group compared to the others (p < 0.05). The 20PP group showed a reduction in perirenal and interscapular fat (p < 0.05), as well as lower plasma concentrations of triglycerides and cholesterol compared to the C group (p < 0.001). In conclusion, PPSC can be incorporated into the diets of growing rabbits up to 20% as a partial substitute for alfalfa without the impairment of growth performance. Additionally, the inclusion of PPSC enhanced nutrient digestibility and increased the intestinal absorption surface area. Full article

Transitioning to a circular economy is crucial for sustainable energy development; yet, current energy supply chains lack comprehensive assessment tools. This study introduces the Holistic Multi-Indicator Decision Support System (HMI_DSS), an innovative tool grounded in life cycle thinking and advanced multi-criteria decision-making methodologies, including Entropy and PROMETHEE II. The HMI_DSS quantifies and assesses sustainability and circularity in energy systems by employing 49 indicators, with a focus on energy efficiency and greenhouse gas emissions. A case study on the rice straw energy supply chain for biogas production illustrates the tool’s effectiveness, comparing a baseline scenario to an alternative. The results show that the global warming potential (GWP) of the baseline is 122 gCO₂eq/kWh, while the alternative is 116 gCO₂eq/kWh. However, the baseline scenario has lower energy consumption (1.72 × 10⁷ MJ annually) than the alternative (1.98 × 10⁷ MJ). Overall, the alternative outperforms the baseline in terms of sustainability and circularity. The HMI_DSS offers a flexible and robust framework for evaluating trade-offs in energy systems, providing valuable insights for energy companies and researchers in adopting circular economy principles to achieve sustainable development. Full article

Carbon dots (CDs) derived from mandarin peel biochar (MBC) at different pyrolysis temperatures (200, 400, 600, and 800 °C) have been synthesized and characterized. This high-value transformation of waste materials into fluorescent nanoprobes for environmental monitoring represents a step forward towards a circular economy. In this itinerary, CDs produced via one-pot hydrothermal synthesis were utilized for the detection of copper (II) ions. The study looked at the spectroscopic features of biochar-derived CDs. The selectivity of CDs obtained from biochar following carbonization at 400 °C (MBC400-CDs towards various heavy metal ions resulted in considerable fluorescence quenching with copper (II) ions, showcasing their potential as selective detectors. Transmission electron microscopic (TEM) analysis validated the MBC-CDs’ consistent spherical shape, with a particle size of <3 nm. The Plackett–Burman Design (PBD) was used to study three elements that influence the F₀/F ratio, with the best ratio obtained with a pH of 10, for 10 min, and an aqueous reaction medium. Cu (II) was detected over a dynamic range of 4.9–197.5 μM and limit of detection (LOD) of 0.01 μM. Validation testing proved the accuracy and precision for evaluating tap and mountain waters with great selectivity and no interference from coexisting metal ions. Full article

The influence of bagasse fibres from beer manufacturing in mechanical, thermal, and rheological properties of three polymers (BioPE, PLA, and PP) has been studied in order to develop new environmentally friendly biocomposites for injection moulding applications. Totals of 10 wt%, 20 wt%, and 30 wt% of bagasse fibre (BSG) were added to the polymers by extrusion compounding, adding specific compatibilising additives, and injected samples were mechanically characterised by tensile, Charpy impact, and hardness tests. In addition, the fractures obtained after the impact test were observed using scanning electron microscopy (SEM) to assess the compatibility matrix filler. Characterisation of the thermal properties is also carried out by using differential scanning calorimetry (DSC) and thermogravimetry (TGA). Additionally, melt flow index of the biocomposites is also studied. An increase in the rigidity of the BioPE and PP composites was produced with the increase in BSG content, dealing with a decrease in maximum strain and impact resistance; whereas, in the filled BGS PLA biocomposites, Young’s modulus was lower than that of the PLA material, improving the ductility of the PLA-BGS formulations. Compatibilisation effect was, therefore, different in the nine developed formulations, and the BGS content also influenced their thermal, mechanical, and rheological behaviours. Full article

Chromite is formed in nature in ophiolitic layers and ultrabasic rocks through fractional crystallization. The corresponding mining technologies separate the ore from these ultrabasic rocks, which are considered to be tailings for the process but may be valorized in other applications. The need to utilize this material is due to the large quantities of its production and the special management required to avoid possible secondary pollution. In the present work, the ultrabasic rocks of chromite mining were applied to acid mine drainage (AMD) neutralization. The aim was to increase the technological maturity of the method and promote circular economy principles and sustainability in the mining sector. Ultrabasic rocks were obtained from a chromite mining facility as reference material. Furthermore, an artificial AMD solution was synthesized and applied, aiming to simulate field conditions. According to the results, the sample was successfully utilized in AMD neutralization (pH 7), achieving rapid rates in the first 30 min and maximum efficiency (liquid to solid ratio equal to 8.3) at 24 h. However, the method presented a drawback since Mg was leached, even though the concentration of other typical metals contained in an AMD solution decreased. Full article

The management of the organic fraction of municipal solid waste (OFMSW), also called urban biowaste, and urban wastewater sludge (UWWS) represents a challenge for cities and regions, which want to adopt innovative urban bioeconomy approaches for their treatment and production of high-added-value products beyond the traditional anaerobic digestion (AD) and compost. This adoption is often restricted by the availability and maturity of technologies. The research object of this manuscript, based on the findings of EU Horizon 2020 project HOOP, is the identification of state-of-the-art circular technologies for material valorisation of OFMSW and UWWS, following a novel screening methodology based on the scale of implementation (tested at least at pilot scale). The screening resulted in 25 technologies, which have been compared and discussed under a multidisciplinary assessment approach, showing their enabling factors and challenges, their current or potential commercial status and their compatibility with the traditional technologies for urban biowaste treatment (composting and AD). The bioproducts cover market sectors such as agriculture, chemistry, nutrition, bioplastics, materials or cosmetics. Therefore, the results of this review help project promoters at city/region level to select innovative technologies for the conversion of OFMWS and UWWS into high value products. Full article

How does the circular economy contribute to the sustainable development of the wine sector? What benefits and limitations can come from the application of the “10Rs”, the circular strategies theorized in 2017 and today a valid tool for the orientation and evaluation of sustainable business models? Through the analysis of 10 case studies (relevant to Northwest Italy), the research confronts a sector of great importance for Italy, the world’s leading wine exporter and second-largest producer. Through the systemic approach, which reads the systems of relationships between matter, energy, information, living beings, inorganic units, and other systems, the 10Rs become filters for a critical reading of winemaking and the post-use phases of wine when the producer’s responsibility meets that of the consumer. A number of relevant issues emerge, in terms of the negative socio-environmental impact of the supply chain; the case studies try to describe them and present a possible ethical and critical response. Although it emerges that the actions of circular economy practitioners focus on the valuing of by-products and waste from the supply chain, rather than on measures to minimize the amount of resources used, extend the life of goods, and reduce waste, the case studies help to broaden this “narrow” view of the circular economy. Full article

This paper presents a study on the establishment and the capitalization of a remontant red raspberry crop, the Polka variety, on a privately agricultural land area of 0.2 ha in a crop with a support system in V using a geotextile membrane for soil mulching and the method of micro-irrigation by drip. It has been shown that the annual gross profit is advantageous for diversifying the population incomes of rural areas, and the red raspberry is economically profitable regarding cultivation because the recovery of the invested sum is achieved in a maximum of 5 years after the establishment of the culture. The aim of this paper is to explore the growth and commercialization of red raspberry cultivation on privately owned arable land in rural Romania, emphasizing its potential for productivity and sustainability in the context of the circular economy. This initiative not only delivers substantial profits for investors but also fosters rural development and boosts local income levels. The study demonstrates that this cultivation method of red raspberry, aligned with the principles of the circular economy, enhances sustainability by reducing waste, optimizing resource use, and involving local communities in production cycles. Full article

Circular economy (CE) research has advanced significantly in recent years in areas like environmental science, engineering, and technology. Governance presents CE strategies as imperative and compelling, often linked to efforts to achieve sustainable business development. However, the financial quantification of a CE is still underexplored and heterogeneous, with multiple research streams exploring the financial dimension. The aims of this study are twofold: (i) to analyze the productivity of the scientific literature and the conceptual evolution of circularity as it relates to financial strategies; and (ii) to formulate future research directions addressing a CE in close connection with financial sustainability knowledge. Bilbiometrix R-package 2023.12.1 and VOSviewer version 1.6.20 were used to analyze a sample of 279 articles retrieved from WoS and Scopus using the PRISMA protocol. The analysis covered the period 2010–2023, with the diachronic thematic analysis revealing four key themes: (1) CE and green financial performance; (2) environmental impact of CE; (3) performance approach of CE and metrics; (4) CE and sustainable development. Building on previous knowledge, we developed an integrated and multidisciplinary framework of CE embedded in financial performance. Future research agenda shaped by the emerging themes and research gaps can support managers, shareholders, or governance in incorporating CE policies into operational activities and strengthening sustainable circularity knowledge. Full article

Industrial metabolism is a recent field of research in engineering and sustainability. Its practical objective is to provide structural solutions to organizations and regulate the productive, ecological, and economic system. Due to being a relatively new topic and without a known pattern, the present research adapts the 4R (resources) urban metabolism MFA model developed at ETH in Switzerland by Professor Peter Baccini and applies it to a Canadian food startup (Missfresh). Within the adjusted model, clean production tools, circularity plans, ecological design, inventory flow analysis, and the four general study variables (materials, infrastructure, impacts, and standards) were used for solutions within the company. This research seeks two academic results: the metabolic map (static–dynamic animation) that describes the behavior of the company during a period of time, and the industrial metabolism model adapted and validated for subsequent applications. In practical results, the impacts of the model in the 3Es of sustainability in the industry and the sector are evaluated: ecology, ergonomics, and economy. This research is conducted within the framework of an internship to obtain a master’s degree in Sustainable Development and Environment at the University of Montreal. Full article

An unsustainable rate of resource production and consumption is evident in urban environments. The absence of innovative approaches in conjunction with the exponential urbanization and expansion of the global population will inevitably result in substantial environmental consequences. There are two emerging alternatives: circular economy (CE) and urban metabolism (UM). The integration of these principles into novel methodology casts doubt on the linear model of contemporary economic and urban systems, which includes extraction, production, utilization, and disposal. In the development of a distinctive urban framework known as circular urban metabolism, the current study has illustrated the application of these principles. We design this study to motivate urban planners and decision-makers to investigate, develop, and supervise ecologically sustainable cities. Scholars from a variety of academic disciplines, intrigued by the intricacies of urban planning, design, and administration, can foster interdisciplinary collaboration in the circular urban metabolism (CUM) region. To address the research question, we implemented a bibliometric analysis, which involved the examination of 627 pertinent research papers, utilizing the R (R 3.6.0+) statistical programming language. The results emphasize the fundamental characteristics and significance of CUM in the management of refuse. In addition, the findings underscore the importance of creating a novel framework that incorporates the principles of urban political ecology, CUM, sustainability, and the novel dimension of waste metabolism. It is the goal of this framework to emphasize the significance of recycling in the informal sector as a waste management strategy in low- and medium-income countries (LMICs). Full article

Waste management involves the systematic collection, transportation, processing, and treatment of waste materials generated by human activities. It entails a variety of strategies and technologies to diminish environmental impacts, protect public health, and conserve resources. Consequently, providing an effective and comprehensive optimization approach plays a critical role in minimizing waste generation, maximizing recycling and reuse, and safely disposing of waste. This work develops a novel Possibilistic Multi-Objective Mixed-Integer Linear Programming (PMOMILP) model in order to formulate the problem and design a circular–sustainable–reliable waste management network, under uncertainty. The possibility of recycling and recovery are considered across incineration and disposal processes to address the main circular-economy principles. The objectives are to address sustainable development throughout minimizing the total cost, minimizing the environmental impact, and maximizing the reliability of the Waste Management System (WMS). The Lp-metric technique is then implemented into the model to tackle the multi-objectiveness. Several benchmarks are adapted from the literature in order to validate the efficacy of the proposed methodology, and are treated by CPLEX solver/GAMS software in less than 174.70 s, on average. Moreover, a set of sensitivity analyses is performed to appraise different scenarios and explore utilitarian managerial implications and decision aids. It is demonstrated that the configured WMS network is highly sensitive to the specific time period wherein the WMS does not fail. Full article

This paper examines the transition of lithium-ion batteries from electric vehicles (EVs) to energy storage systems (ESSs), with a focus on diagnosing their state of health (SOH) to ensure efficient and safe repurposing. It compares direct methods, model-based diagnostics, and data-driven techniques, evaluating their strengths and limitations for both EV and ESS applications. This study underscores the necessity of accurate SOH diagnostics to maximize battery reuse, promoting sustainability and circular economy objectives. By providing a comprehensive overview of the battery lifecycle—from manufacturing to recycling—this research offers strategies for effective lifecycle management and cost-effective, environmentally sustainable secondary battery applications. Key findings highlight the potential of second-life EV batteries in ESSs. The integration of the considered diagnostic methods was shown to extend battery lifespan by up to 30%, reduce waste, and optimize resource efficiency, which is crucial for achieving circular economy objectives. This paper’s insights are crucial for advancing sustainable energy systems and informing future research on improving diagnostic methods for evolving battery technologies. Full article

As the whisky industry applies circular economy principles to maximize resource utilization and minimize environmental impact, companies become exposed to several risks, which require complex assessments to ensure reliable outcomes. This study provides an organized framework to identify, prioritize, and rank various risk factors commonly observed in the whisky industry through the development of an analytical hierarchy process (AHP) multi-criteria analysis model. Experts from 18 small European distilleries identified five main risk criteria and nineteen sub-criteria from brainstorming workplace observations and categorized them as: environmental (5), operational (4), technological innovation (3), food safety (3), and economical (4) risks. The analytical hierarchy process (AHP) approach was used to determine the weights and ranks of the main criteria and sub-criteria based on the survey responses received from experts from each distillery. The final judgements are consistent, as indicated by consistency values (CR) of less than 0.1 for all risk criteria. Unlike traditional risk assessment methods, the AHP model effectively integrates qualitative and quantitative data, aiding strategic decision making in the whisky industry by breaking down complex problems into manageable sub-problems. Future research directions may expand the criteria and explore additional sustainable practices. Full article