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Improving water vapor barrier of cellulose based food packaging using double layer coatings and cellulose nanofibers Texto completo
2022
Al-Gharrawi, Mohammed Z. | Wang, Jinwu | Bousfield, Douglas W.
Paper based packaging has the potential to replace many plastic-based systems if the required barrier properties can be obtained. Water borne barrier coatings have the potential to generate good barrier layers, but their performance is often less than expected. Recent work has shown improved performance of these coatings when applied on paper that has a cellulose nanofiber layer. Here, papers with a cellulose nanofiber layer were coated with barrier coatings at different coat weights applied as single-layers, as double-layers, and single-layers pressed together in a hot press in order to generate a packaging system that has good barrier properties. The performance of double-layer samples resulted in moisture transmission rates that were 40–70 % of the value of the single-layer systems. Surprisingly, the hot-pressing of two dry layers showed no advantage compared to the single-layer system. A barrier pigment added to one formulation improved the performance further and followed the same trends. Three dimensional models of diffusion through layers that have defects help explain the results. The work shows a potential path to produce paper-based packaging that has both good oxygen and water vapor barrier properties.
Mostrar más [+] Menos [-]Interactive quantitative modeling and cost optimization of regional sustainable development based on water-energy-food nexus Texto completo
2022
Wang, Jiangjiang | Wang, Jiahao | Ge, Wenbiao | Xie, Kangzhen
As the critical resources for regional development, water, energy and food (WEF) are highly interdependent. Improving the cognition of the complex interactions of WEF nexus is the top priority of regional sustainable development and decision-making. This paper proposes a novel regional water-energy-food interaction model based on supply and demand to clarify the nexus between WEF resources and its impact on the development of the entire region. An indicator of sustainability index is employed to quantitatively evaluate the interactions between supplies and demands in WEF nexus. The scenario analysis method is used to predict the resources and demands for the future medium and long-term development in a high-tech industrial zone, China, and then the total regional cost is optimized to obtain the suitable development roadmaps. The analysis results indicate that energy is the key to WEF and significant regional development. The collaborative development of WEF, including the supply of external resources, can better promote the sustainability of the region. Appropriate adjustment of energy structures and power generation ratios can not only effectively reduce the total cost, but also control CO₂ emissions. The proposed WEF model with the indicator of sustainability index can quantitatively evaluate the region sustainable development.
Mostrar más [+] Menos [-]Understanding barriers to collaborative governance for the food-energy-water nexus: The case of Phoenix, Arizona Texto completo
2022
Jones, J Leah | White, Dave D.
Food-energy-water (FEW) nexus governance includes the communication and collaboration among multi-level stakeholders across sectoral boundaries of the resources for decision-making. It can increase resource security and decrease unintended consequences, as compared to single-sector governance approaches. Despite these benefits, in practice, many decisions continue to be made separately from one another without cross-sector collaboration. This research integrates the theory of collaborative governance with the concept of the FEW nexus to identify and understand the barriers to this collaboration and to provide recommendations for increased collaborative FEW nexus governance. Focusing on the Phoenix, Arizona metropolitan area, a water-scarce region with a growing population, we conduct a comprehensive case study with social network analysis, participant observation, and interviews. We present the results of our analysis in three sections. First, we identify the key barriers to collaborative FEW nexus governance within four identified themes: structural asymmetries, process asymmetries, communication and coordination, and external influences. Second, we unpack how stakeholders in our study case experience these barriers. Finally, from our case study, we provide recommendations for overcoming barriers and implementing collaborative FEW nexus governance in practice, such as building trust and finding mutual benefit. We conclude that “sector mismatch,” similar to scale mismatch, is the main cause of the identified barriers and that approaches to collaborative FEW nexus governance must address this mismatch for successful engagement.
Mostrar más [+] Menos [-]Sustainability transitions of urban food-energy-water-waste infrastructure: A living laboratory approach for circular economy Texto completo
2022
Valencia, Andrea | Zhang, Wei | Chang, Ni-Bin
Urban areas often face versatile stressors (e.g., food security, congestion, energy shortage, water pollution, water scarcity, waste management, and storm and flooding), requiring better resilient and sustainable infrastructure systems. A system dynamics model (SDM), explored for the urban region of Orlando, Florida, acts as a multi-agent model for portraying material and energy flows across the food, energy, water, and waste (FEWW) sectors to account for urban sustainability transitions. The interlinkages between the FEWW sectors in the SDM are formulated with multiple layers of dependencies and interconnections of the available resources and their external climatic, environmental, and socioeconomic drivers through four case studies (scenarios). The vital components in the integrated FEWW infrastructure system include urban agriculture associated with the East End Market Urban Farm; energy from the fuel-diverse Curtis H. Stanton Energy Center; reclaimed wastewater treated by the Eastern Water Reclamation Facility, the Water Conserv II Water Reclamation Facility, and stormwater reuse; and solid waste management and biogas generation from the Orange County Landfill. The four scenarios evaluated climate change impacts, policy instruments, and land use teleconnection for waste management in the FEWW nexus, demonstrating regional synergies among these components. The use of multicriteria decision-making coupled with cost-benefit-risk tradeoff analysis supported the selection of case 4 as the most appropriate option as it provided greater renewable energy production and stormwater reuse. The SDM graphic user interface aids in the visualization of the dynamics of the FEWW nexus framework, demonstrating the specific role of renewable energy harvesting for sustainably transitioning Orlando into a circular economy.
Mostrar más [+] Menos [-]Assessing the development potential of non-food biofuel crops under the water-land-biofuel nexus perspective Texto completo
2022
Yang, Jiashuai | Gao, Chan | Wang, Xi | Fu, Hao | Xu, Chaowei | Wang, Yizhen
Facing water and land scarcity, planting non-food biofuel crops on marginal land depending on natural rainfall has been considered as an attractive means of achieving sustainable biofuel development. However, the complex connection between rainfall and marginal land resources in spatial-temporal distribution affects the optimal planting layout of non-food biofuel crops as well as the assessment of biofuel potential, especially in arid areas. In this study, we constructed a water-land-biofuel nexus centered on non-food biofuel crops, optimized the layout of three non-food biofuel crops, sweet sorghum, Jerusalem artichoke and switchgrass, based on fuzzy mathematics method under the water-land-biofuel nexus perspective, determined yield-rainfall curve to calculate the development potential of non-food biofuel crops. The results showed that sweet sorghum and Jerusalem artichoke are more suitable for planting in Ningxia. Three potential scenarios are set up under different growth conditions and agricultural technologies. The theoretical biofuel production is [9.64× 10⁷, 10.93× 10⁷] GJ, which was verified by the result that the biofuel production per unit area is close to the lower limit of the test production range. It can also be speculated that there may exist irrigation supply and fertilization in the actual crops planting in other studies.
Mostrar más [+] Menos [-]A distributed robust optimization model based on water-food-energy nexus for irrigated agricultural sustainable development Texto completo
2022
Guo, Shanshan | Zhang, Fan | Engel, Bernard A. | Wang, Youzhi | Guo, Ping | Li, Yinong
Sustainable agricultural development covers all aspects of agricultural production involving the water-food-energy nexus (WFEN) and considers the effects of agricultural activities on society, economy and ecology. Multi-objective optimization models play an important role in making tradeoff among multiple interests of stakeholders. Aimed at canal-based irrigated agricultural areas, water allocation highly depends on canal distribution, and the spatial location of irrigation regions determines their water-intake order, which usually induces serious water allocation inequality. The social, economic and ecological problems resulting from water inequality would deteriorate without intervention and seriously impact sustainable development. Thus, optimization models must consider water use equity, water-intake order as well as water equilibrium simultaneously. However, this will greatly increase computational efforts and solution difficulty. The problem becomes worse when uncertain factors are involved. In order to overcome these difficulties, a distributed multi-objective uncertain optimization model was established to help develop comprehensive strategies for agricultural sustainability. A novel robust solution method was proposed to offer an efficient way to handle stochastic and fuzzy uncertainties from the perspective of feasibility and optimality robustness. Finally, a case study was conducted to demonstrate the practical application of the developed model. The results offer managers insights on agricultural sustainable development.
Mostrar más [+] Menos [-]Numerical modelling of conjugate heat and mass transfer during hydrofluidisation food freezing in different water solutions Texto completo
2022
Stebel, Michal | Smolka, Jacek | Palacz, Michal | Eikevik, Trygve M. | Tolstorebrov, Ignat
A novel method of hydrofluidisation food freezing is numerically investigated in this paper. This technique is based on freezing small food products in a liquid medium under highly turbulent flow conditions when the heat transfer coefficient is higher than 1 000 W⋅m⁻²⋅K⁻¹, which depends on the operating and flow conditions. A numerical model was developed to characterise the freezing process in terms of the heat transfer and diffusion of liquid solution components into the food product. The study investigates the freezing process of spherical samples in binary solutions of ethanol (30%) and glycerol (40%) and ternary solution of ethanol and glucose (15%/25%). The developed model was employed to determine the concentration of the liquid solution in food samples and to quantify the effect of sample size, heat transfer coefficient, solution temperature and concentration on the process. The food sample size varied from 5 to 30 mm, and the heat transfer coefficients varied from 1 000 to 4 000 W⋅ m⁻²⋅ K⁻¹. The results confirm that a freezing time of 15 min for 30 mm diameter samples or less than 1 min for 5 mm diameter samples can be achieved with the hydrofluidisation method. The solution uptake was influenced by the solution type, sample size and process parameters and varied from 8.9 to 35 g of solute per kg of product for ethanol-glucose and glycerol solutions, respectively. This paper quantifies the advantages and possible limitations of hydrofluidisation, which has not yet been entirely studied, especially in terms of the mass absorption of different solutes.
Mostrar más [+] Menos [-]Possibility for Water Quality Biocontrol: Observation of Microcystin Transfer in the “Cyanobacteria–Cladohorn–Fish” Food Chain Texto completo
2022
Qin-Ming Xie | Yan-Wei Zhang | Ta-Jen Chu
Microcystins appear to be considered one of the most dangerous cyanobacterial toxins in the world. The accumulation and change of microcystins MC-LR and MC-RR in the “cyanobacteria–cladocera–fish” food chain were studied. <i>Microcystis aeruginosa</i> was fed to <i>Moina macrocopa</i> at three densities, 5.0 × 10<sup>3</sup>, 5.0 × 10<sup>5</sup>, and 5.0 × 10<sup>6</sup> cells/mL, and then passed to <i>Cyprinus flammans</i>. The total amount of MCs in the cyanobacteria cell extract increased with increasing density. The content of MCs in <i>M. macrocopa</i> increased with the feeding density of <i>M. aeruginosa</i>. In the final stage of experiments, MC-RR was the only MC that could be transmitted by <i>M. macrocopa</i> and persisted in red carp. In this study, changes in the concentrations of MC-LR and MC-RR in the liver of red carp seem to indicate some kind of transformation or degradation mechanism. It shows the possibility of MCs concentration-controlled biodefense in eutrophic waters.
Mostrar más [+] Menos [-]Analysis of the Coupling Characteristics of Water Resources and Food Security: The Case of Northwest China Texto completo
2022
Xian Liu | Yueyue Xu | Shikun Sun | Xining Zhao | Yubao Wang
Exploring the coupling characteristics of regional water resources and food security helps to promote the sustainable development of grain production and is of great significance for achieving global food security. From the aspects of regional “water supply”, “water use” and “water demand”, the coupling characteristics of water resources and food security were systematically revealed; the new challenges faced by regional food security from the perspective of water resources were clarified; and effective ways to promote the utilization of regional water resources and the sustainable development of grain production were explored. This paper took Northwest China, which is the most arid region, where water-resource utilization and food security are in contradiction, as the research area. The water-resource load index, the water footprint of grain production and the water-consumption footprint were used to quantify the regional water-resource pressure index, as well as the residential grain-consumption types, population urbanization, the industrial-grain-processing industry and their corresponding water-consumption footprints from 2000 to 2020. The coupling characteristics of water resources and food security were systematically revealed. The results showed the following: (1) In 2000–2020, the water-resource load index increased from 4.0 to 10.7, and the load level increased from III to I. At the same time, agricultural water resources were largely allocated elsewhere. (2) During the period, the food rations showed a significant decreasing trend, and the average annual reduction was 3.4% (<i>p</i> < 0.01). The water footprint of animal products increased, particularly for beef and poultry (the average annual growth rates were 9.9% and 6.3%, respectively). In addition, the water footprint of industrial food consumption increased by 297.1%. (3) With the improvement of the urbanization level, the water-consumption footprint increased by 85.9%. It is expected that the water footprint of grain consumption will increase by 39.4% and 52.3% by 2030 and 2040, respectively. Exploring how to take effective measures to reduce the water footprint to meet food-security needs is imperative. This study proposed measures to improve the utilization efficiency of blue and green water and reduce gray water and the grain-consumption water footprint from the aspects of regional planting-structure optimization potential, water-saving irrigation technology, dietary-structure transformation and virtual water trade; these measures could better relieve the water-resource pressure and promote the sustainable development of grain production and water-resource utilization.
Mostrar más [+] Menos [-]Assessing the water quality of the Seine land-to-sea continuum for three agro-food system scenarios Texto completo
2022
Romero, Estela | Garnier, Josette | Billen, Gilles | Ramarson, Antsiva | Riou, Philippe | Le Gendre, Romain
Three scenarios for the future of the French agro-food system were specified for the territory draining into the Seine Bight, comprising Paris megacity and the Seine watershed. The first scenario assumes the pursuit of the current trend of opening and specialization of agriculture, as well as of concentration of population within the Paris agglomeration. The second scenario assesses the generalization of agro-ecological practices and a healthier human diet. A third, hybrid, scenario was elaborated assuming that agro-ecological practices were implemented in some protected areas (namely Regional Natural Parks and drinking water protection areas, making up about one-third of the total watershed area), while the rest of the territory will follow the trends of the first scenario. We use a unique modelling chain (GRAFS-Riverstrahler-ECOMARS3D) that couples the biogeochemical functioning of the river basin, the estuary and the adjacent bay. It allows exploring the implications of changes in terrestrial activities throughout the aquatic continuum in a consistent way and assessing to what extent changes in population, agricultural practices, food consumption, and sanitation may sustain the current trend of recovery in the Seine River or either increase stress on the system. Results show that only the full agro-ecological scenario would be able to restore good water quality everywhere in the river network, as well as decrease significantly the risks of toxic algal blooms in the coastal zone. Intermediate situations, such as the protection of specific areas, however attractive as a solution, are not enough to offset the impacts of intensive human activities unless the protected areas dedicated to compensating for damage are sufficiently large.
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