Yoon, Pu ReunLee, Sang-HyunChoi, Jin-YongYoo, Seung-Hwan...
16页
查看更多>>摘要：As the uncertainty and importance of securing resources increase, the nexus concept is used for integrated sustainable use management planning. In particular, because protected farms are most affected by temperature change, the connection between the heating temperature variable and resources must be analyzed. In this study, a water-energy-food-carbon nexus model that reflected the agricultural characteristics of protected farms was constructed. The crop yield, irrigation amount, and heating energy were simulated, and a sensitivity analysis was performed according to climate change scenarios and heating temperature variables. There was no significant decrease in the yield of food resources even at heating temperatures lower than 12( circle)C. In contrast, the growing period shortened as the heating temperature increased above 12( circle)C, which decreased the irrigation amount but tended to increase the heating energy. In addition, lowering the heating temperature standard from 12 C- circle to 8( circle)C (or less) is suitable for efficient resource management.
查看更多>>摘要：The degradation of two poly(ethylene terephtalate) (PET) samples from urban and marine wastes (PET-u and PET-m, respectively) has been studied by comparing their properties with those of virgin PET (PET-v) and post condensed PET for bottle fabrication (PET-ssp). FTIR spectroscopy, DSC analysis, WCA and MFI results have confirmed that all PET residues were degraded. Therefore, the chemical recycling has been evaluated in order to valorize PET-m and PET-u wastes, analyzing the effect of degradation on the process. Glycolysis of degraded and non-degraded PET samples has been carried out in a pressure reactor at 220C for 30 min. For all the cases almost pure BHET monomer has been obtained: 96.5 and 96.7 % for PET-m and PET-u respectively, values 2 and 13 % higher than those obtained for PET-ssp and PET-v. Obtained results indicate that the initial degradation of PET wastes increases the BHET monomer content in the glycolyzed sample.
Wang, ChuanshengDing, MeiyueNg, Tze Chiang AlbertNg, How Yong...
11页
查看更多>>摘要：This work successfully developed a novel vibrating AnMBR (VAnMBR) and investigated its long-term performance, fouling control and energy recovery compared to the conventional biogas-sparging AnMBR (BSAnMBR). The VAnMBR achieved better organics removal compared to the BSAnMBR due to the lower content of biopolymers in its effluents. Moreover, the VAnMBR retarded the early TMP rise to alleviate membrane fouling efficaciously with 49.7%-80.2% lower fouling rates than the BSAnMBR. Reduced amounts of nano-particles were consistently observed in the supernatants of the VAnMBR, revealing its benefits to restrict fouling sources for better fouling control. Importantly, the VAnMBR could save 81.9%-94.1% energy of the BSAnMBR and enhance 11.1%-35.0% biogas recovery resulting from minimised dissolved methane, inducing more net energy production during wastewater treatment. The favourable performance of the VAnMBR makes it a promising technology to replace the conventional wastewater treatment plant as a next-generation resource recovery facility.
查看更多>>摘要：The wastewater treatment plants are transforming to water resource recovery facilities. The essence behind this transformation is to recover resources from wastewater as much as possible instead of destroying and removal. By far, a wide array of products (energy, fertilizer, etc.) in wastewater and recovery technologies have been identified. However, only a few technologies have been extrapolated into full-scale practices. Herein, cellulose is such a kind of resource originating from toilet paper and its recovery has been implemented and endorsed by research efforts in terms of environmental and economic favourability. This review aims to comprehensively map the technologies of cellulose recovery from wastewater and clarify the associated internal impact and external market potential. First, the source, fate, and transformation of cellulose in a typical WWTP (applying activated sludge) are analyzed to provide a holistic overview of the recovery potential and points. Second, cellulose recovery technologies are reviewed and summarized in a historical timeline with an emphasis on rotating belt filters. Particularly, the impacts of cellulose recovery on wastewater treatment performance and the valorization routes are introduced and discussed comprehensively to make the benefits more explicit. The third section of the review presents a discussion in terms of sustainability and some other factors/routes to manage toilet paper and cellulose. Considering the mature value chain, versatile application routes, and favorable environmental impact, cellulose recovery is highly recommended to be included in wastewater management.
查看更多>>摘要：Decarbonizing the building stock plays an important role in realizing climate change mitigation targets. To compare the decarbonization potential of different strategies, this study presents a spatiotemporal bottom-up dynamic building stock model that integrates material flow analysis, building energy modeling, and life cycle assessment. It can simulate future building stock evolution at the component level and track the associated material flows, energy demand and generation, and GHG emissions with the consideration of both endogenous factors (e.g. building energy efficiency upgrade) and exogenous factors (e.g. policies, occupant behavior, and climate scenarios). The model is applied in the residential building stock of Leiden, a municipality in the Netherlands. Results show that annual GHG emissions are reduced by about 40% under the reference scenario while annual GHG emissions can be reduced by about 90% under the ambitious scenario where all the decarbonization strategies are simultaneously implemented. Natural-gas-free heat transition and renewable electricity supply are the most effective strategies, respectively reducing the annual GHG emissions in 2050 by an additional 21% and 19% more than the reference scenario. Rooftop PV, green lifestyle, and wood construction have similar decarbonization potential (about 10%). Surplus electricity can be generated if rooftop PV systems are installed as much as possible. The decarbonization potential of demolition waste recycling is much smaller than other strategies. The model can support policymakers in assessing the decarbonization potential of different policy scenarios and prioritizing decarbonization strategies in advance.
查看更多>>摘要：Limited adoption of advanced technologies and land fragmentation limit the sustainable intensification of agriculture in developing countries. Here, we explore and establish an integrated management strategy by combining the public-private partnership (PPP) and large-scale farming (LSF) for more profitable and sustainable no-tillage maize production. A case study was conducted in the North China Plain to determine the applicability and the key drivers underpinning PPP-LSF success. On average, maize under PPP-LSF yielded 10.4 Mg ha(-1), which was 11.8% and 19.4% greater than that of LSF and smallholder farming (SHF), respectively. Compared with LSF and SHF, the PPP-LSF achieved the highest energy use efficiency and the lowest negative environmental externalities. The carbon footprint of PPP-LSF was 267 kg CO2-eq Mg-1, which was 32.7% and 38.2% lower than that of LSF and SHF, respectively. A new causal factor analysis developed in this study revealed that the mechanised application of controlled-release formula fertilisers, eliminating top-dressing, was the main factor for low carbon footprint in PPP-LSF. The mean net ecosystem carbon budget (NECB), sustainability index, and net ecosystem economic benefit of PPP-LSF were 22.5 Mg C ha(-1), 17.1 and 2040 $ ha(-1), respectively, which were increased by 15.3% and 23.9%, 55.5% and 69.3%, and 28.7% and 50.3% compared with LSF and SHF. Higher net primary productivity related soil carbon sequestration potential and lower field carbon emissions were the main drivers of high NCEB of PPP-LSF. This real-world commercial crop production-based example illustrates the value and potential of PPP-LSF in utilising modern innovative farming technologies and management strategies to accelerate agricultural productivity and resources conservation with reduced environmental footprints.
查看更多>>摘要：Carbon dioxide valorization through microbial electrosynthesis (MES) is promising due to it's potential for mild operating conditions and stable long-term performance. Previous MES studies have typically shown poor organic production rates using direct electron transfer mechanisms, prompting the use of electrochemically generated H-2 to provide reducing equivalents for improved carbon utilization via metabolisms like the Wood-Ljungdahal pathway. Still, CO is a more favorable electron donor than H-2 as it provides more thermodynamic reducing power for conversion of CO2 into valuable products. Here, we incorporated highly selective cobalt phthalocyanine catalysts into new planar 2D and porous 3D MES cathodes to produce syngas rather than H-2 and boost the overall bioconversion rates of CO2 into value-added products (i.e. acetate and ethanol). Both the 2D and 3D systems were able to consistently generate syngas for over 250 h using microbial media electrolyte, demonstrating excellent stability in challenging electrolyte conditions. However, the 2D planar cathodes required a larger potential to maintain similar current densities as the 3D porous cathodes (-1.8 V vs. -1.2 V vs. Ag/AgCl) and showed a slow decline in CO production (0.23 ml/min-0.09 ml/min) and increase in H-2 (0.01 ml/min-0.13 ml/min) production after 250 h. In comparison, the 3D porous electrodes allowed for more stable CO (0.08-0.06 ml/min) and H-2 (0.16-0.06 ml/min) generation that also led to higher maximum acetate (5.1 vs. 3.8 g/L) and ethanol (1.2 vs. 0.9 g/L) titers. Demonstration of these new cathode materials shows significant progress towards more stable and effective MES operations and delivers useful insight on syngas mediated electron transfer and utilization in bioelectrochemical systems.
查看更多>>摘要：As apanoramic overview of the multipronged national-scale regulations of China to synchronously decelerate climate change and improve air quality, this study pores through a constellation of China's strategies aimed to obtain coinstantaneous reductions in the emissions of atmospheric pollution and greenhouse gases (GHGs). These strategies, inclusive of afforestation and silviculture, ultra-low industrial emissions, energy structure reform, renewable energy development, household emission reductions, transportation emission control, and shutdown of cryptocurrency mining, have vouchsafed China new pragmatic dimensions in pursuit of its climate goals and have established a roadmap to bide time for the future. Here we show blow-by-blow the pros and cons of these pathways to illustrate the reasons why they best serve China's long-term targets and dovetail with China's geopolitical realities. Because of the interactions between air pollutants and GHGs, cooperatively reducing the emissions of both air pollutants and climate change gases have mutual benefits and are efficacious for the enhancement of air quality and mitigation of global warming.
查看更多>>摘要：Local governments have made extensive efforts to mitigate urban overheating, cool streetscapes and cities, and protect vulnerable people. However, there is uncertainty about which urban heat mitigation strategies (UHMSs) can provide better solutions for a specific urban context. There is a compelling need for local governments to automate the decision-making process and optimise the combination of UHMSs to maximise the mitigation outcomes for their cities. We develop a novel decision-making framework that incorporates artificial intelligence (AI) techniques into urban heat mitigation in the built environment to enable an automated process of decision making. The novel decision-making framework comprises: the ontology-based knowledge representation of UHMSs and their relationships with urban contexts and performance assessment to share knowledge in urban heat mitigation domain; sensitivity analysis of the environmental, social and economic performance of UHMSs to get key variables for UHMSs; and genetic algorithm-based multi-objective optimisation of UHMSs. The novel decision-making framework enables generating the context-based optimised UHMS combinations to support local governments' decision-making. The research outcomes will advance interdisciplinary knowledge about using AI techniques in the decision-making process for urban heat mitigation.
NSTL
Elsevier