查看更多>>摘要：Large-scale development of bioenergy is indispensable in dealing with the climate change challenge. The biomass resource may become a limiting factor for the utilization of bioenergy in mitigating carbon emissions in the future. For supporting formulating a feasible long-term strategy for bioenergy development, it is crucial to conduct an ex-ante estimation of the biomass resource potential and accurately capture its variability at fine resolution. Although many previous studies have been carried out to estimate biomass resource potential, there is still a lack of a systematic assessment of the long-term spatio-temporal distribution of resource potential of multiple domestic biomasses in the context of future changes of human and natural factors. To address this research gap, this study proposed a comprehensive framework coupled with the crop growth models, RS-GIS methods, statistical downscaling, and multi-source dataset to evaluate the biomass resource potential and its variability across China at 1-km resolution from 2020 to 2100. This study identified the suitable areas for bioenergy development in the future, and analyzed the impact of climate change and land use change on biomass resource potential. This study also explored the role of bioenergy potential playing in China's energy supply under the temperature rise control target. Results indicate that the bioenergy potential of residues and energy crops in China will reach 5.11-11.01 EJ in China in 2100, only accounting for 5.3%-12.2% of the national primary energy supply demand in 2100.
查看更多>>摘要：Recently, with the deterioration of the environment, increasing companies choose horizontal cooperation to achieve the goal of reducing environmental pollution and cost in the urban distribution industry. However, companies worry that the business information is leaked in the process of horizontal cooperation. This kind of mistrust often leads to the failure of horizontal cooperation. The emergence of blockchain technology has become a great means to resolve trust problem between partners, which ensures data sharing and trust through peer-to-peer, consensus mechanism and encryption technology. In response, this study proposes architecture of blockchain-based urban distribution system for horizontal cooperation that analyzes the components and layers of the urban distribution. Meanwhile, a smart contract, the innovative applications of blockchain, is designed to match the resource of supply and demand to design the distribution routes in the urban distribution system. To achieve the above goal, an open vehicle routing model of urban distribution taking into account environmental pollution factors is developed as the mathematical logic of smart contract, which aims at the lowest total cost including fixed, fuel, penalty, carbon emission and pollutant emission costs. Furthermore, the genetic algorithm is developed to support the implementation of smart contract, and the effectiveness of the smart contract is verified through a real case. This study narrows the knowledge gap in applying blockchain technology to urban distribution, and has brought contributions to the fields of blockchain and urban distribution. Finally, the limitation and future research direction are discussed.
查看更多>>摘要：Unprecedented urbanization is dramatically altering habitual food consumption in urban China, and consequently affecting diet-linked greenhouse gas emissions (DGHGEs). Building on the representative resident survey data from the China Health and Nutrition Survey, this study analyzed urban food consumption profiles and related GHG emissions from a life cycle perspective. Moreover, a CATREG (Categorical Regression) model was conducted to identify influencing factors. Results show that urban residents in China generate an average of 2.92 kg CO(2)e/capita/day, with 1.06 kg of foods consumed. Meat consumption has a dominant role in urban DGHGEs and is the main driver of variation in the DGHGEs. Urbanization level and most demographic factors with regard to household and individual characteristics have significant impacts on urban DGHGEs. However, the resident's awareness of the Chinese Dietary Guideline dose not significantly contribute to promoting low-GHG urban diets. A novel result of this analysis is that local ecological conditions, including geographical climate and resource endowments, have evident effects on urban food consumption and the related GHG emissions, despite the fact that urban areas heavily rely on food resources imported from other regions. Our findings offer knowledge-based inspiration geared to sustainable urban food consumption for both China and other developing countries.
查看更多>>摘要：The transition towards a Circular Economy necessitates the development of methodologies for optimal utilization of secondary resources. One such resource is sewage sludge ash (SSA). SSA can be utilized in construction materials, but as it contains a high concentration of the critical raw material phosphorous (P), extraction of P before the use in construction materials must be considered. EasyMining in Sweden has developed a method for acid extraction of P (Ash2Phos). This work investigates the use of the acid-washed SSA from this process (AW-SSA) in concrete; as partly sand or cement replacement. Castings of mortar prisms showed that a 10% direct replacement of the sand fraction was not possible, as the AW-SSA had a high water demand. Subsequently, the workability was too low for casting. Grinding the AW-SSA before use as cement replacement, on the other hand, gave encouraging results. At 10% replacement, the mortar had a similar 28-day compressive strength as the reference. The Strength Activity Index and Frattini Test did not show conclusive results; however, the AW-SSA is probably not pozzolanic. However, the ground AW-SSA likely has a (latent) hydraulic nature, positively influencing late strength development. The 42-day compressive strength of mortar with 10% replacement exceeded that of the reference with about 5 MPa. This latent hydraulic nature underlines an interesting potential for transforming SSA into two products; phosphorous and material for partly cement replacement in concrete.
查看更多>>摘要：Important advances have been made to define the multiple impact pathways relating mineral resource use to the area of protection (AoP) natural resources in life cycle assessment (LCA). Yet, the link between stakeholders' interests and the aspects relevant to resource use as addressed by existing impact assessment methods has so far only marginally been explored. This article proposes to go beyond the case-specific determination of stakeholders' interests (and the associated selection of impact assessment method) by defining multiple groups of different values based on cultural perspectives, in order to determine the corresponding relevant impact pathways and assessment methods. Relying on the Cultural Theory and related potential development scenarios, we identify socio-economic objectives and resource management strategies that fit the egalitarian, individualist and hierarchist perspectives. Our analysis reveals that different aspects of resource use may be most relevant to assess for each perspective since they pursue different socio-economic objectives. Egalitarians are expected to prioritize the long-term availability of geological stocks for future generations by keeping extraction flows to a minimum to reach global sufficiency, and individualists, to safeguard their short-term accessibility to resources by managing their supply risk. Hierarchists are likely to aim to maximize the value obtained from resources globally, and could thus focus on addressing dissipative flows. Building on this analysis, we provide a proposal for a more holistic assessment of the impact pathways linked to mineral resource use using existing LCIA methods, and identify ways forward for method developments to come.
查看更多>>摘要：The decentralization of waste management argues to support better planning, fair distribution of material and economic resources, and increased citizen participation. This study aims at assessing the environmental and economic performance of a decentralized biowaste management system, using the frameworks of life cycle assessment and net present value analysis. Five scenarios are designed to reflect the transition from an energycentered biowaste management (scenario 1) towards a novel biorefinery system (scenario 2) and its expansion to a decentralized network (scenarios 3, 4, and 5) of small-scale plants treating urban biowaste. The global warming potential of the energy-centered system is 134 kg CO2 eq, while the biorefinery system offers mitigation of the global warming by -4324 kg CO2 eq t 1 biowaste treated. The decentralized network designed to capture 20% of the urban biowaste generated in Lyon Metropolitan (S5) provides environmental (S5a: -1983 kg CO2 eq, S5b: -1992 kg CO2 eq) and economic (S5a: 491_, S5b: 475_) benefits, especially when collection is performed with electric bikes (S5b) and the bio-products substitute resource and energy intensive equivalents in the market. Collection with electric bikes contributes to a low-carbon economy while significantly increases labor costs. The transition towards a bio-based economy can transform biowaste management into novel cascading biorefineries of multiple high-value products. Resilient and optimized system design can support low carbon economies and increase employment while being economically sustainable.
Kaliyavaradhan, Senthil KumarPrem, Prabhat RanjanAmbily, P. S.Mo, Kim Hung...
20页
查看更多>>摘要：The exponential development of the electronic industry and changes in people's lifestyle have increased the discarding rate of waste electronic appliances and electrical equipments rapidly. The disposal of electronic waste (e-waste) has become a serious challenge to developing and developed countries as toxic substances and heavy metals present in e-waste could harm human health and the atmosphere. From the perspective of environmental concerns, it is necessary to properly dispose or reuse e-waste in any forms to prevent pollution. In recent years, a growing number of studies are primarily associated with utilization of e-waste as construction materials. This paper provides a critical and comprehensive review of different types of e-waste which can be utilized as source material in the form of binder, fine/coarse aggregate, and fibre in the mortar, concrete, and precast products. More specifically, this review highlights the positive aspects, future research needs, and limitations of using e-waste in construction. Overall, it is suggested that e-waste offers huge potential benefits when it is utilized in construction products, thereby reduces e-waste management problems and saves the earth from environmental pollution.
查看更多>>摘要：This study reports the preparation and characterization of alkali-activated slag based geopolymer foamed material (GFM). The roles of rice husk ash (RHA) on thermal stability and thermal insulation of GFM were systematically investigated. Thanks to the low self-weight and good reactivity of RHA, the compressive strength and specific compressive strength of GFM are enhanced, promoting the lightweight and high-strength developments of GFM. More importantly, the replacement of GGBS by RHA efficiently mitigates the strength degradation, reduces the weight loss and increases the volumetric stability of GFM during thermal exposure. The thermal conductivity of GFMs registered from 0.1102-0.2891 W/m.K reflects good thermal insulation characteristic, which is better than the reported thermal insulation properties of other alkali-activated foamed materials system at the same strength/density level. The mechanism of RHA acting on GFMs is closely related to the property characteristics of RHA itself, basic properties enhancement and pore structure development of GFMs. With the use of 20 wt.% RHA, the GFM containing 2 wt.% H2O2 exhibits the optimal comprehensive properties: 0.01270 x 10(3).kN.m/kg specific compressive strength, 827 kg/m(3) volume density, 10.5MPa compressive strength, 0.1331 W/m.K thermal conductivity and better volumetric stability.
查看更多>>摘要：The supply-managed Canadian egg industry produces over 789 million dozen eggs per year, the majority of which are produced in conventional cages (similar to 60%). Recently, the industry committed to a complete transition to alternative (i.e. enriched cage, single- and multi-tier free run, free range, and organic) production systems by 2036. This transition may have significant sustainability implications. Here, we present updated (i.e. based on 2019 data) LCA models and results representing the cradle to farm gate environmental impacts of Canadian egg production systems based on a much expanded data set compared to previous models. Generally, input and emission levels decreased across all housing systems, with few exceptions, compared to previously reported levels. Acidifying and GHG emissions decreased across most housing systems due to increases in feed- and pullet-use efficiency, while eutrophying emissions increased across all housing systems modeled due to differences in manure management systems. Feed inputs represented the greatest contributor to most impact categories (similar to 18% - 84%), followed by pullet production and manure management (similar to 10% - 37% and similar to 0.01% - 62%, respectively). Organic production systems had the lowest impacts in nine of the ten categories assessed, while free range systems generally performed the worst. Conventional cages generally had lower impacts than all non-organic systems. However, it can be expected that as farmers gain experience with alternative systems resource-use efficiency levels will increase and environmental impacts will decrease. Continued monitoring of environmental performance of Canadian egg production systems is therefore imperative to ensure net-positive outcomes during this housing system transition.
查看更多>>摘要：Significant progress has been made in reducing air pollution across China after years of efforts. However, it remains uncertain as to how these changes in pollution have influenced disease burden. Furthermore, only limited data are available with regard to the spatiotemporal patterns of air pollution related disability-adjusted life-years (DALYs) across China. Using multi-parameter and random-forest derived PM2.5 and O-3 concentrations from 2005 to 2017 and based on the updated non-linear integrated exposure-response functions (IERs), we estimated the county-level PM2.5- and O-3-related DALYs across China and explored the spatiotemporal trends. In 2017, the ambient PM2.5 and O-3 were estimated to cause 0.894 million premature deaths and 22.77 million DALYs in China. From 2005 to 2017, the DALYs related to PM2.5 declined across China, especially after 2013, although levels remained high. The DALYs related to O-3 are generally increasing, although at a lower rate when compared with PM2.5. Approximately 96.7% of the PM2.5-related DALYs, and 94.8% of the O-3-related DALYs, are from the southeast side of the Huhuanyong Line, of the country. The reduction of air pollution in China has led to a significant improvement in health. Higher related DALYs were observed in regions with dense populations and higher concentrations of PM2.5 and O-3. Different pollutants and related outcomes are associated with different spatial patterns and change trends. Strict regulatory policies, and coordinated and regional-specific measurements are needed to continually reduce air pollution and mitigate the health burden caused by air pollution in China.
NSTL
Elsevier