Resources, conservation & recycling advances最新文献

Agent-based modeling is a promising approach in industrial symbiosis (IS) simulation due to its bottom-up approach. However, the role of implementing feasible technologies in agent-based modeling of IS has been underexplored. In this paper, an agent-based model was developed to optimize the economic benefits of IS stakeholders in a case study region. Feasible technologies were integrated into the proposed model to generate additional economic profit and enhance circularity. The model was implemented on a case study involving a chicken farm, cow farm, dairy, edible oil plant, and a Combined Heat and Power (CHP) plant. Technologies including anaerobic digestion, organic Rankine cycle, heat pump, and membrane separation were employed to produce biogas, recover waste heat, and purify wastewater. While the fossil-based energy consumed by industries reduced, all the waste streams could be recovered. The techno-economic specifications of these technologies had a significant impact on the symbiotic relationships.

The focus on food supply chain (FSC) sustainability has grown due to demand, food loss and waste, and environmental impacts. This study aims to quantify citrus life cycle costs (LCC) and determine the main drivers and their contributions. LCC was used to assess the cradle-to-grave cost of 1 kg of citrus sold to consumers at the retailer stage. A comparison was made between an existing citrus supply chain (SC) and a proposed closed-loop structure. In addition to the current citrus SC, four different cases were analyzed and evaluated: the centralized linear citrus SC, the centralized linear citrus SC with a 33 % increase in labor income, the centralized closed-loop citrus SC, and the centralized closed-loop citrus SC with a 33 % increase in labor income. The results showed significant reductions in functional unit's (FU) costs of 48 %, 38 %, 54 %, and 44 %, respectively, compared to the current citrus SC. Labor accounted for 47–62 % of the FU costs, while agriculture inputs and transportation contributed 15–28 % and 12–16 %, respectively. The study revealed that a centralized citrus closed-loop SC improves economic viability, especially when recycling citrus waste as compost for farms. Transportation currently contributes the most to FU costs (45 %), but in the closed-loop citrus SC, labor becomes the highest contributor (62 %). This cradle-to-grave citrus SC approach identifies drivers and contributions to the FU's costs, showcasing differences when integrating a circular economy. Future research may explore the impact of other byproducts on FU costs.

The impact of global warming on the construction sector is a serious issue in today's world; this might be attributed to the emission of greenhouse gas (GHG) during the production process of Portland cement. Due to its advantages, cement plays a major role in the construction of civil infrastructures. Cement production is not only responsible for global warming and also creates a risk of raw material deficiency. To reduce the over exploitation of virgin materials, Limestone Calcined Clay Cement (LC³), with a proportion of Clinker 50 %, Limestone 30 %, Calcined Clay 15 % and gypsum 5 %, is found to be a suitable and sustainable alternative to preserve the ecosystem. As a result, attempts were undertaken in this work to create a mixture design approach for LC³ with the primary objective of developing higher compressive strength (CS) in a cost-effective manner. The relationship between the water to binder ratios and 28-d CS has been examined to suggest a conceptual mixture design strategy for LC³ rationally. The 28-day CS of 46.2 MPa has been observed. The suggested design technique has been presented step by step and validated using an example based on the guidelines illustrated by IS 10,262. The design technique aims to produce a concrete mix that meets specific strength, workability, and durability requirements while considering the environmental conditions and properties of materials available. The study emphasizes a systematic approach to concrete mix design, considering various factors like water-cement ratio, aggregate proportions, and workability requirements to ensure the resulting concrete meets the desired performance standards. Compliance with IS 10,262:2019 ensures that concrete used in construction is designed systematically and according to established guidelines, leading to higher quality and more predictable performance in structural applications. Further, to access the sustainability of the developed LC³ mix Life-Cycle Assessment (LCA) of LC³ was reported starting from raw material procurement to the production of concrete as the final product. In this LCA analysis, the monetary cost involved in the production of concrete, energy demand and GHG emission of the LC³ was compared with the conventional concrete. The result from the analysis revealed that LC³ possess superior performance in terms of energy requirement and GHG emission than the OPC concrete.

A considerable amount of electricity is additionally demanded for Electric Vehicle (EV) charging due to rapid EV penetration. This study explores the impact of time of charging for different levels of passenger EV penetration on the electricity system using a case study electricity system with high penetration of renewable energy resources. A simulation approach is proposed to determine the new demand profile due to EV charging. Next, a Mixed Integer Linear Programming model is formulated considering the operation schedules of conventional power plants to mimic the real-time status of the electricity system. Finally, the developed approach considers the different possible interventions of actual EVs available in the market and tries to determine their impact in a renewable energy-dominated electricity system. The results from the study show that it is emission-friendly to encourage night charging rather than day charging for the considered renewable energy-dominated case study electricity system.

The construction industry requires significant quantities of material and energy resources, which are either recycled or disposed as waste after demolition. Circular Economy (CE) facilitates the benefits of reuse and recycling of Construction and Demolition Waste (CDW) and promotes the industry in cradle-to-cradle or “Resolve” paradigms. However, in emerging economies, the industry merely achieves to harness a negligible amount of the CDW's intrinsic monetary benefit and sustainability, due to multiple barriers to circular practices. This study examines barriers that obstruct the incorporation of circular economy practices in the Indian construction industry. The study uses Relative Importance Index (RII), Factor Analysis, and Regression analysis to arrive at a list of macro-environmental barriers to the use of CE in CDW. The findings are presented using the PESTEL framework, with Political, Social, and Economic factors being the dominant barriers to the use of CE in CDW in emerging economies. Results from this study point towards the need for better guidelines by regulators for recycling of CDW, incentive schemes, and overall capacity building in emerging economies.

Crop production benefits from nutrients in animal wastewater, but direct usage has had an adverse impact on the environment. This impact could be mitigated by electro-precipitation of nutrients from wastewater for recovery as solid fertilizer. However, to recover these nutrients at high rates and minimize energy consumption requires an efficient evaluation of independent variables on these responses. This paper provides these analyses by evaluating the effect of five independent variables – temperature, cathodic potential, turbulence and molar ratios (Mg²⁺:Ca²⁺and N:P) – on phosphorus and nitrogen removal efficiencies and specific energy consumption.

Screening results indicate electrochemical P-removal was most affected by the Mg:Ca ratio, while N-removal was inconclusive due to the experiment duration. The specific energy consumption was most affected by Mg:Ca ratio, temperature and N:P ratio and could be made competitive with industrial routes by controlling these three variables. Overall, for the conditions assessed, struvite formation was most favored at lower temperatures.

The circular economy (CE) represents a shift away from society's traditional linear ‘take, make, disposal’ model of consumption, which exacerbates resource scarcity and climate change. It could also enable built environment sectors like rail infrastructure to operate and provide value for society more sustainably. However, while various strategies could support the CE transition, there is little evidence of their implementation for rail infrastructure to date. Also, despite growing research addressing CE practice in the built environment sector, most articles rely on secondary data. There is a need for more research based on primary data to bring new insights and guide the industry towards CE implementation. This research investigates the importance of CE implementation strategies, barriers and enablers for UK rail infrastructure projects through an industry-wide survey. It discusses the findings of an online questionnaire (n=50) and 15 semi-structured interviews with representatives from UK rail industry organizations. The results generally show rail infrastructure as being less commercial, but also more permanent, risk-averse and resistant to change. As such, value optimization and life extension should be more relevant than for buildings. However, greater resistance to change may hinder CE implementation, which is seen as requiring a paradigm shift away from the current linear model of consumption. Client leadership will be key in this respect, because of their scale, influence and long-term responsibility for asset ownership, but they may require support from government to overcome various structural factors. Government could also help by setting CE procurement requirements in contracts for rail infrastructure projects.

Groundwater is a critical resource that is utilized for a variety of reasons, but over-extraction can lead to a number of environmental and socioeconomic issues such as diminished water supply, land subsidence, and pollution. To manage groundwater resources in a sustainable manner, proper monitoring, regulation, and conservation strategies are required. Groundwater contamination in India is growing as a result of population increase and industrialisation, which can have serious health and environmental consequences. To avoid groundwater pollution, it is critical to monitor and control possible sources of contamination, as well as to promote sustainable farming practices and the use of less hazardous pesticides and fertilizers. To get a better knowledge of groundwater pollution, the current study attempted to analyse the quality of groundwater in the neighbourhood of the Vellalore dump yard (located in Coimbatore, India), encompassing an area of 161.87 hectares. To examine the quality of groundwater in the contaminated region, several physical and chemical properties such as pH, dissolved oxygen, total dissolved solids, and water quality index were measured. The majority of the water samples from the region are classed as low quality and unsafe for drinking. The plume appears to be migrating northerly and northwest from the landfill location, most likely due to the natural slope of the dump site towards the northwestern direction. The bulk of the gathered samples have low water quality, making the water unfit for even basic residential use. These findings highlight the need of local governments taking proactive efforts to protect the groundwater in this area, pushing for a comprehensive approach to prevent additional pollution. The report emphasizes the critical need for local governments to take prompt action to prevent additional groundwater pollution by establishing a comprehensive strategy.

Municipal solid waste (MSW) management is a major challenge for cities worldwide, particularly in Africa. This study used an emission-reduction framework to assess the economic benefit of sustainable MSW management in Sub-Saharan Africa (SSA) over a 60-year period (2000–2060). Two waste-to-energy (WTE) methods, sanitary landfills and anaerobic digestion, were used to assess the potential electricity generation from MSW under four waste collection scenarios. The assessment was compared to the potential economic damage from cumulative methane (CH4) emissions under business-as-usual waste management practices for the same period. The results show that energy recovery from current MSW generation forecasts can contribute to 100–245 kWh per capita electricity generation between 2025 and 2060, depending on the WTE technology employed. The net present value (NPV) of WTE technologies is less than half the dollar cost of the potential economic damage from methane emissions. These results have significant policy implications for increasing access to sustainable and clean energy in SSA countries. Given that the current average per capita electricity generation in SSA is 158 kWh and that several countries in the area are experiencing energy problems, MSW electricity generation offers untapped economic development prospects. These findings highlight the economic advantages of effective waste management in SSA to mitigate future environmental and climate change consequences of greenhouse gas emissions. Furthermore, this study underscores the need for stakeholders to develop cost-effective and sustainable waste management strategies to avoid possible future economic and environmental damage in SSA.

Multiple stakeholders are responsible for the supply chain redesign for the transition to Circular Supply Chains (CSCs). Despite it has been demonstrated that certain supply chain (SC) capabilities and Digital Technologies (DTs) can play a determinant role on the design of specific CSC archetypes, current knowledge remains still sparse. To fill this research gap, we conduct a Systematic Literature Review. Results show that specific SC capabilities are required for closing (inter-sectorial collaboration, intra-sectorial collaboration, flexibility, visibility, traceability), slowing (inter-sectorial collaboration, intra-sectorial collaboration, flexibility, visibility, traceability), narrowing (inter-sectorial collaboration, intra-sectorial collaboration, flexibility, visibility, traceability), intensifying (intra-sectorial collaboration, inter-sectorial collaboration, flexibility, visibility), and dematerializing (inter-sectorial collaboration, visibility) resource streams. In a similar way, the combination of DTs is proven useful for closing (BDA, AI, AM, IoT, BC, CC), slowing (BDA, AI, AM, IoT, BC, CC), narrowing (BDA, AI, AM, IoT, BC), intensifying (AM, IoT, BC, CC), and dematerializing (BDA, AI, AM, IoT, BC, CC) resource streams.