查看更多>>摘要：Because poverty and natural resource conservation are multi-dimensional, complex interactive processes, ecological compensation (EC) mechanism, which is global environmental resource management policy instruments, have become important tools for poverty alleviation. This study developed a unified analysis framework that incorporated a tripartite evolutionary game that included EC-investors, who promote eco-compensated poverty alleviation, EC-providers, and superior government regulators. Based on proposed dynamic replicator equations, the evolution and steady state strategies for each of these stakeholders were then separately discussed. A numerical study based on the observable conditions in an eco-compensated poverty alleviation project was conducted to examine the asymptotic stability of the various evolutionary stabilization strategies. The results show that the government regulator's strategic choices act as a "weathervane" for the other two players, and the choice of the superior government regulator depends on the expected benefits and costs of the strategy. The strategic choices made by the EC-providers are significantly influenced by the EC-investor strategy choices, with a sufficient ecological transfer payment being the main motivation for the providers to participate in the eco-compensated poverty alleviation projects.
Souza, Fernando da SilvaMendes, Julia CastroBarbosa Morais, Lya JuliaSilva, Jonatas Santos...
16页
查看更多>>摘要：Due to the scarcity of aggregate deposits in the region of the Brazilian Amazon, cities such as Rio Branco (state of Acre) rely on complex logistical operations to guarantee their supply. These operations substantially raise the cost of natural aggregates and, together with their environmental impact, justify the recycling of construction and demolition waste (C&DW) in the region. Therefore, the present study investigates the quantity and composition of the C&DW generated in the urban area of Rio Branco and proposes a recycling plant for the city. Periodic and systematic visits to construction sites were carried out to formulate representative indexes for the generation and composition of the C&DW. These indexes supported an economic feasibility analysis for the recycling plant, as well as a discussion of the environmental impact of this plant on the inert landfill currently used in Rio Branco. As a result, a C&DW generation index per constructed area of 0.22 t/m(2) was found for new construction works and 0.41 t/m(2) for renovation works, with unit weight of 0.98 t/m(3) and 0.92 t/m(3), respectively. According to its composition, 100% of C&DW was deemed reusable and/or recyclable. In the last 20 years (1999 - 2018), 3.2 million tonnes of C&DW were generated in the city, averaging 517 kg/(inhab.year). Economic indicators show feasibility for the installation of a recycling plant with a processing capacity of 90 t/h, improving the environmental, economic, and social aspects of the construction sector in the area.
查看更多>>摘要：This study employed the methodology of life cycle assessment (LCA) to assess the environmental impacts of rubberized semi-dense asphalt (SDA) pavement. Asphalt mixtures were prepared at the asphalt plant, followed by hybrid approach of mechanical and leaching tests in the laboratory to assess the possible service life and PAH leaching. The LCA was carried out considering two scenarios: (1) the reference scenario focuses on standard SDA produced of only virgin materials; (2) the test scenario refers to rubberized SDA using crumb rubber, a secondary material from waste tires. In the reference scenario, waste tires were assumed to be used as fuels for clinker production; while in the test scenario, waste tires were applied for SDA and primary fuels were used for clinker production (system expansion approach). In a sensitivity analysis, a scenario with waste tire treatment in municipal solid waste incinerators (MSWI) was also assessed. The impact assessment includes greenhouse gasses (GHG) emissions, nonrenewable cumulative energy demand (CED), human and ecotoxicity (USEtox), and the Swiss method of ecological scarcity. The results indicate that the investigated impacts were not improved by the test scenario. The USEtox results also reveal that the leaching impacts can be as serious as binder production and material transport if PAHs emit to groundwater. From an environmental point of view in Switzerland, it is not recommended to promote rubberized SDA by reducing the waste tires used for clinker production. However, if there are waste tires used for MSWI, the rubberized SDA is still an environmentally viable option.
查看更多>>摘要：The ever-growing production of non-recyclable plastic products causes plastic pollution to be the one of most pressing environmental issues. The transition of petrochemical-based plastic with eco-friendly biodegradable plastic has become the promising solution to overcome the plastic pollution crisis. Recent research addressed the production of polyhydroxyalkanoates (PHA), which is a class of bioplastic through the valorisation of wastewater sludge. However, the high production cost and limited process feasibility studies hinder the commercialisation of the waste-derived PHA synthesis process. Since there is a lack of exploration on material integration by implementing an industrial symbiosis network that could potentially enhance the sustainability of waste-derived PHA production, this paper proposes the optimisation of bioplastic production by creating a carbon-hydrogen-oxygen industrial symbiosis network (CHOSYN) to solve sludge management and resources consumption problem concurrently. The atomic targeting approach is used to benchmark the resources and waste discharge from the model. The findings indicate that the proposed process framework attains sustainability improvement in economic and environmental aspects as compared to the conventional PHA synthesis process. An optimal biorefinery eco-industrial park (EIP) design with the involvement of PHA production is presented and the implication of results obtained is also discussed in this article.
查看更多>>摘要：Emerging economies, particularly China, are likely to play a critical role in determining global food waste. The paper investigates plate waste from a staple food consumption pattern perspective by surveying 9,192 Chinese university students at the on-campus canteens in 29 provinces of mainland China. A significant finding is that diet culture is closely related to food waste. Southerners who consume rice as a staple food are found to waste more food than Northerners who are wheat-based eaters on average. A robust test confirms the finding when matching the student's hometown and university location and setting the "Southerners studying in South China" as the reference group. Taking into account the possible self-selection problem, the robustness test based on the PSM model also confirms the association between staple food consumption patterns and food waste in Chinese university canteens. Comparative analyses based on the components of food consumption and the compositions of wastage further suggest that the differences in staple food consumption patterns determine the food wastage variations. This study provides empirical evidence that differences in consumption patterns bring about the disparity in food wastage within a country.
Soares, Camila Tavora de MelloEk, MonicaOstmark, EmmaGallstedt, Mikael...
10页
查看更多>>摘要：Multi-material multilayer plastic packaging (MMPP) is widely applied in fast moving consumer goods (FMCG) combining functionalities of distinct materials. These packaging structures can enhance properties, such as resource-use efficiency and barrier performance leading to consequential benefits like a prolonged shelf-life. Nevertheless, they represent a challenge for existing recycling systems, confronting circular economy principles. This study aim was to foresight the future of recycling technologies for MMPP in the next five to ten years. Future scenarios were identified, including (1) high-performance material recycling, (2) recycling into hydrocarbons, (3) business as usual, and (4) downcycling. In-depth interviews and a feedback survey were methods used to validate the scenario matrix while defining experts' expectations towards the future. The analysis showed that distinct technologies will develop unevenly in different parts of the world. A mix of all scenarios is probable in the upcoming years, depending, essentially, on regulations and technology availability. Advanced high-performance material recycling encounters systemic bottlenecks, such as insufficient sorting technology for post-consumer waste. In contrast, chemical recycling (feedstock) is concentrating investments as a solution, requiring low input-characterization. Additionally, design for recycling trends might reduce multilayers' complexity. A gap between recycling targets and recycling technologies was identified, representing short-term opportunities for more sustainable materials, such as bio-based.
查看更多>>摘要：The generation of Waste Electrical and Electronic Equipment (WEEE) continues to escalate yearly because of high demand for state-of-the-art and affordable devices. This demand is particularly strong for small consumer electrical and electronic equipment whose usage cycle is waning due to fashion and technological obsolescence. As a result, there is potentially a large 'pool' of unused, reusable devices within urban spaces (anthroposphere). This study aimed to assess the magnitude of the reusable stock of EEE with the view to recovery and release into the circular economy. An online questionnaire survey was conducted within a regional group of universities in the United Kingdom to assess the prospects of reusable small EEE within this distinct urban mine (DUM) cluster. The study provides new, distinct definitions for types of DUM, hoarding and stockpiling, and new data for a 'meso-level' DUM on ownership levels and hibernating stocks of reusable EEE. Results show that ownership levels were high, with multiple ownership of devices common and a high degree of product stockpiling and hoarding. Estimates show a stockpile of similar to 400,000 small EEE within the survey zone and over 17 million devices across the UK with reuse values of >13 pound million and >571 pound million, respectively. The frequency of device stockpiling is likely due to perceived residual value. The study suggests that exploitation of reuse value requires prompt recovery of stockpiled items as extended periods in hibernation will result in technical obsolescence, particularly with information and communication technology (ICT) devices. Such recovery requires tailored protocols that considers DUM scale, product reusability, recyclability and redistribution.
查看更多>>摘要：This study examines a green building retrofit plan through a system dynamics model (SDM) creating symbiosis embedded in a building-scale food-energy-water (FEW) nexus. An indicator approach was employed to exploit cross-domain seams via the use of carbon, water, and ecological footprints for sustainability, as well as food security and energy supply reliability ratio for resilience. The SDM was formulated to demonstrate a continuous stormwater treatment outflow model for rooftop farming with stormwater reuse for irrigation, nutrient cycling via the use of green sorption media, and green energy harvesting in support of rooftop farming. We prove that green energy use, stormwater reuse, and rooftop farming can lower carbon, water, and ecological footprints, avoid CO2 emissions via carbon sequestration in rooftop farming, and improve energy supply reliability and food security. Case 1 (Base Case) includes no retrofit (current condition), Case 2 includes rooftop farming and stormwater reuse, and Case 3 incorporates additional green energy harvesting for sustaining rooftop farming. All three scenarios were assessed using a life cycle assessment (LCA) to generate water and carbon footprints. Case 3 exhibited a 2.24% reduction of total building energy demand from the utility grid due to renewable energy harvesting, while the preservation of nitrogen and phosphorus via the use of green sorption media for crop growth promoted nutrient cycling by maintaining 82% of nitrogen and 42% of phosphorus on site. The ecological footprints for the three case studies were 0.134 ha, 0.542 ha, 6.50 ha, respectively. Case 3 was selected as the best green building retrofit option through a multicriteria decision analysis.
查看更多>>摘要：Co-processing is considered as an effective way to reduce the cost and environmental footprints for cement production by replacing fuel or raw materials with wastes. In this study, we investigated the influences of co-processing of heavy metal-contaminated soil in cement kiln on the engineering integrity and heavy metal leachability of cement powders and cement mortars. The replacements of the contaminated soil were set at 0, 3.0, 7.6, and 10.0 wt.%. Engineering integrity of the cement products was verified first using typical performance tests, followed by three heavy metal leaching tests, namely Toxicity Characteristic Leaching Procedure (TCLP), EDTA-mediated TCLP and Synthetic Precipitation Leaching Procedure (SPLP). The results showed that in TCLP, only Cr was the concern, in which leachates of cement powders produced by co-processing with > 7.6% soils exceeded the TCLP Cr limit (5.0 mg/L), whereas all leachates of cement mortars met the regulations. EDTA-mediated TCLP could potentially release higher Cr concentrations, indicating that cautions were still needed when applying the cement products in harsh environments. Preliminary economic assessment indicated that using co-processing to treat heavy metal-contaminated soils can bring benefits for both cement industry and soil polluter. Overall, cement kiln co-processing could be an attractive alternative for the remediation of heavy metal-contaminated soil to revive the contaminated site and reduce the environmental impacts of cement production.
NSTL
Elsevier