查看更多>>摘要：Unconventional oil and gas (UOG) production requires a vast quantity of freshwater while generating substantial volumes of wastewater. Although numerous studies have focused on technology development, other aspects beyond treatment technology, including regulations, economics, system logistics, and public perception, play equally or more important roles collectively in the selection and deployment of UOG wastewater management practices. In this article, we begin with a critical analysis of the motivations that drive UOG wastewater management towards treatment and reuse. Then we examine four main barriers against such a paradigm shift, pertaining to treatment technology, regulatory compliance, economic feasibility, and social acceptance. Despite the need of further improving technology efficiency for UOG wastewater treatment, the lack of established regulatory framework, the uncertainties of economic viability, as well as public resistance, hinder practical implementation of treatment technologies. We highlight the importance of knowledge and collaborative efforts from engineers, regulators, policy makers, economists, and social scientists to address those barriers, and emphasize that future research efforts should be directed at domains well beyond treatment technology. A systems approach and broader collaboration across multiple disciplines is needed to translate technology innovation into solutions that truly improve water sustainability in the context of rising UOG production.
查看更多>>摘要：Defossilizing the energy and industrial systems and transformation towards a circular economy have versatile impacts on the availability and demand of alternative resources. However, systematic analyses on these interrelations are very sparse. Thus, this paper investigates the interlinkages between the energy transition and the transformation towards a circular economy in Germany. The study is based on material flow analysis models of the steel and cement industries as well as the coal and lignite power plants in order to depict a comprehensive description of the material, energy and emission flows of these sectors and their interdependencies. The analyses prove the inherent interrelation between energy transition and circular economy. On the one hand, energy transition does not only bear various techno-economic challenges and have substantial effects on the production costs, but it also affects the availability of secondary materials. For instance, the coal phase-out and the introduction of green steel imply that the current supplies of blast furnace slag, fly ash and FGD gypsum cannot be maintained. On the other hand, circularity approaches can also influence the energy transition. For example, banning single-use plastics and increasing recycling rates of plastics can deprive the cement industry from significant amounts of energy resources with low-carbon footprint. Contrariwise, CO2 recycling can promote the energy transition by means of mitigating CO2 emissions via carbonation. Therefore, the study can help policymakers to understand the indirect effects of existing and future policies. Also, it can help to develop future strategies to handle associated impacts and avoid material shortages.
查看更多>>摘要：European Commission has promulgated a series of directives to divert MSW from landfills to more sustainable management options. To investigate whether the directives affect the MSW management practice locally, the transition of MSW management in Nottingham, UK, since the enforcement of the EU Landfill Directive, has been assessed by combining materials flow analysis (MFA) and life cycle assessment (LCA). The results confirm that paralleled to the enforcement of the EU directives MSW management system in Nottingham evolved from a simple landfill and energy from waste (EfW) mode to a complex multi-technology mode. Landfill rate has been reduced through waste prevention, material recycling, and energy recovery. The complex multi-technology mode contributed to the reduced GHG emission per unit waste treated from 1,076.0 kg CO2-eq./t in 2001/02 to 228.1 kg CO2-eq./t in 2019/20. The temporal correlation between enforcement of EU directives and the progression of the MSW management in Nottingham depicted a trickle-down effect of the directives driving the improvement of local MSW management. Similar temporal patterns were exhibited among the EU member states. Interestingly, some European countries whose landfill rate already surpass the requirement prior to the enforcement of the related EU directives continued advancing waste management system, mostly incentivized by extracting valuable materials or energy from the well-sorted waste. This incentive, aligning with the principle of circular economy, may become the future drive of cities like Nottingham, who either achieved the regulatory targets or without regulatory incentives by the international governmental bodies.
查看更多>>摘要：With the rapid development of e-commerce and the modern fast-paced life in large Chinese cities, food delivery services have become an important part of daily life and inevitably result in significant amount of food delivery waste (FDW) and environmental impacts. However, the scales, patterns, and impacts of FDW remain hitherto poorly understood. This study, based on direct weighing method (810 samples) and questionnaire survey (889 samples), aims to address such gaps with a case study for Wuhan, a typical first-tier city in central China. Our results showed that Wuhan's total FDW added up to 177.6 (+/- 52.9) kilotons in 2019, in which white-collar workers contribute the most (58%) and packaging waste takes up a significant share (32%). When packaging waste is excluded, the amount of FDW varied significantly among consumer groups, i.e., 154 +/- 69, 187 +/- 97, and 249 +/- 124 g/cap/order for urban residents, college students, and white-collar workers, respectively, indicating the predominant role of consumer characteristics on FDW generation. Wuhan's total FDW related carbon emissions were approximately 168.3 kilotons CO(2)e; and this can be reduced by 25% if waste-to-energy technology can be implemented as planned and by 55% if the avoidable part of FDW can be prevented. Raising awareness and encouraging thriftiness (e.g., via education and public campaigns), nudging and pricing to minimize irrational food purchase, and reducing unnecessary packing and use of disposal dishware, are suggested as important FDW reduction strategies.
查看更多>>摘要：Pervious concrete pavement has great potential in reducing surface water runoff and improving water quality. This study aims to conduct life cycle assessment (LCA) and multi-criteria assessment of pervious concrete pavement with the use of fly ash. The research significance lies in the integration of hydraulic and structure designs for developing functional unit of pervious concrete pavement and combining environmental impacts with engineering and economic indicators. A full LCA of pervious concrete pavement system was conducted including the stages of material, construction, transportation, use, maintenance, and end-of-life stage. The impact assessment included global warming potential, energy consumption, and eutrophication potential due to runoff purification. The pervious concrete pavement structures were designed based on mechanical properties of mixtures, hydrological requirement of reservoir layer, and subgrade soil type to meet equivalent performance on parking lot and highway shoulder. Multi-criteria analysis of pervious concrete mixes and pavement systems were presented based on the normalization of environmental impacts, engineering performances, and economic costs. The LCA results showed that the environmental impacts of pervious pavement system were mainly generated from material stage in terms of 81% to 92% GHG emissions and 70% to 83% energy consumption. The performance rankings of pervious concrete mixes were different from those of pervious pavement structures. The pervious concrete pavement with fly ash can cause greater or less environmental impact, depending on mechanic properties of pervious concrete and the required surface layer thickness to achieve equivalent structural performance.
Ye, QuanliangBruckner, MartinWang, RanranSchyns, Joep F....
13页
查看更多>>摘要：Lacking systematic supply-use information of agricultural biomass and food products within China makes the existing provincial environmental pressure assessments (e.g., water consumption) either not detailed enough (e. g., by the input-output table-based approach) or not comprehensive enough (e.g., by the process-based approach). This study develops a symmetric inter-provincial multi-regional input-output (MRIO) model that hybridizes the physical food and agricultural biomass system with the monetary supply chain of China. First, we construct the inter-provincial supply, use, and input-output tables in physical units of 84 agriculture, food and forestry products. These physical supply/use/MRIO tables systematically capture agri-food product flows, at an unprecedented level of product detail, along domestic supply chains within China. Then we integrate the physical MRIO table of agri-food products into the monetary all-sector MRIO table to construct a symmetric hybrid MRIO table of China. The application of our hybrid MRIO model to the case of provincial blue water footprint assessments reveals that the hybrid model enhances both the monetary MRIO table-based approach and the process-based approach from different aspects. For instance, the hybrid MRIO model can reduce the uncertainty of monetary MRIO modeling due to the aggregation of products with different environmental properties into homogeneous sectors. Lastly, uncertainty analysis is implemented to quantify the main sources of uncertainties, and understand the reliability of our new hybrid MRIO model for future sustainable development design.
查看更多>>摘要：Analyses of the future for manufacturing and heavy industries in a climate constrained world many times focus on technological innovations in the early stages of the value chain, assuming few significant changes are plausible, wanted, or necessary throughout the rest of the value chain. Complex questions about competing interests, different ways of organising resource management, production, consumption, and integrating value chains are thus closed down to ones about efficiencies, pay-back times, and primary processing technologies. In this analysis, we move beyond this to identify archetypal pathways that span across value chains in four emissions intensive industries: plastics, steel, pulp and paper, and meat and dairy. The pathways as presented in the present paper were inductively identified in a multi-stage process throughout a four-year European research project. The identified archetypal pathways are i) production and end-use optimisation, ii) electrification with CCU, iii) CCS, iv) circular material flows, and v) diversification of bio-feedstock use. The pathways are at different stages of maturity and furthermore their maturity vary across sectors. The pathways show that decarbonisation is likely to force value chains to cross over traditional boundaries. This implies that an integrated industrial and climate policy must handle both sectoral specificities and commonalities for decarbonised industrial development.
查看更多>>摘要：According to the Environmental Protection Agency's National Emissions Inventory Report, hundreds of thousands of tons of particulate matter (PM2.5) are released by diesel combustion per year (Enviromental Protection Agency 2020; Hammer et al., 2020). The toxic PM2.5 air pollution causes serious public health problems and is responsible for millions of worldwide deaths each year (Apte et al., 2015). In this study, we investigate the electrochemical energy storage capability of annealed soot PM originating from diesel exhaust. Soot composite electrodes were utilized as anode electrodes and cycled against Li counter electrodes. X-ray diffraction and Raman spectroscopy showed the graphitized carbon structure of the annealed soot particles. The cycle life and rate capability of the electrodes were investigated via galvanostatic cycling tests. The electrodes exhibited excellent rate performance with discharge capacities of 235, 195, 150, 120, and 80 mAh/g when cycled at rates of 1C, 2C, 5C, 10C, and 20C, respectively. The electrode demonstrated an initial discharge capacity of 154 mAh/g at a 4C rate with a capacity retention of almost 77% after 500 cycles. Raman analysis confirms the retention of structural ordering in the soot carbon after 500 cycles. Kinetic analysis, obtained through cyclic voltammetry at different scan rates, indicates pseudocapacitive charging behavior in the soot composite electrode. Our study provides a viable pathway towards a sustainable energy environment by converting an abundant toxic pollutant into a valuable electrode material for Li-ion batteries.
查看更多>>摘要：Microbial fuel cell (MFC) is a feasible technology for uranium removal and recovery from uranium-containing wastewater. However, the accumulation of reductive product (UO2) on the cathode surface hindered the continuous removal of uranium due to the increase of over-potential. In this study, we developed a microbial electrolysis cell (MEC) system in a mixed microbial consortium with a low energy input that can continuously remove uranium on the UO2-coated cathode. Thermodynamic calculation results demonstrated that the cathode potential controls U(VI) removal in the MEC system, and U(VI) removal was the contribution of the microbial process and the applied voltage (Eap). Experimental results indicated that the cathode potential for the electrochemical reduction of U(VI) on the UO2-coated cathode was about -0.64 V vs. Ag/AgCl, whereas the microbial species in the anode of MEC can provide an Ecathode of -0.47 V vs. Ag/AgCl. Therefore, only a small Eap (about 150 mV) can trigger the continuous U(VI) removal in the MEC. The continuous removal capacity of the UO(2)coated cathode was evaluated over 15,830.86 mu mol m(-2), and the removal efficiencies were higher than 94.0% after all the 22 cyclic tests. Furthermore, over 98.0% of uranium can be recovered from the cathode by acid or alkali method, and the recovery process does not affect the electrode itself. The excellent continuous removal capacity and reusability of the electrode demonstrate that MEC is a promising technology for U(VI) removal from wastewater.
查看更多>>摘要：Food loss has been widely identified as a key barrier to food security and environmental sustainability in developing countries. However, there remains a lack of empirical studies on the scales and patterns of food loss along the food supply chain in developing countries especially with updated and primary data. In this study, we aim to address this significant gap for China, based on a large-scale field study with questionnaire survey and qualitative interview of 1809 farmer households in 35 major agricultural producing counties of 12 provinces across China between April 2017 and September 2019. Three main agricultural products, staple food, vegetables, and fruits, and their entire supply chain from agricultural production to post-harvest handling, storage, processing, and distribution were covered. The normalized total losses of staple food, vegetables, and fruits added up to 7.9%, 27.7%, and 13.2%, respectively, of their total production. The major loss of staple food occurs at production stage, while post-harvest handling stage and distribution stage, respectively, contribute the most to vegetables and fruits losses. Although China's leapfrogging progress and technology development in recent years have resulted in a reduction of food loss, it was estimated that between 40% and 60% of these losses can still be further mitigated. Such primary data could improve our understanding on the scales and patterns of supply chain food losses in China and thus better inform food loss reduction interventions and associated economic and environmental mitigation strategies.
NSTL
Elsevier