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Recycling Possibility of the Salty Food Waste by Pyrolysis and Water Scrubbing Texte intégral
2017
Ye-Eun Lee | Jun-Ho Jo | Sun-Min Kim | Yeong-Seok Yoo
Salty food waste is difficult to manage with previous methods such as composting, anaerobic digestion, and incineration, due to the hindrance of salt and the additional burden to handle high concentrations of organic wastewater produced when raw materials are cleaned. This study presents a possibility of recycling food waste as fuel without the burden of treatment washing with water by pyrolyzing and scrubbing. For this purpose, salty food waste with 3% NaCl was made using 10 materials and pyrolysis was conducted at temperature range between 200–400 °C. The result was drawn from elementary analysis (EA), X-ray photoelectron spectroscopy (XPS) analysis, atomic absorption spectrophotometry (AAS) analysis, water quality analysis and calorific value analysis of char, washed char, and washing water. The result of the EA showed that NaCl in food waste could be volatilized at a low pyrolysis temperature of 200–300 °C and it could be concentrated and fixed in char at a high pyrolysis temperature of 300–400 °C. The XPS analysis result showed that NaCl existed in form of chloride. Through the Na content result of the AAS analysis, NaCl remaining in char after water scrubbing was determined to be less than 2%. As the pyrolysis temperature increased, the chemical oxygen demand (COD) value of scrubbing water decreased rapidly, but the total phosphorus and nitrogen contents decreased gradually. The cleaned pyrolysis char showed an increase of higher heating value (HHV) approximately 3667–9920 J/g due to the removal of salt from the char and, especially at 300–400 °C, showed a similar HHV with normal fossil fuels. In conclusion, salty food waste, which is pyrolyzed at a temperature of 300–400 °C and cleaned by water, can be utilized as high-energy refuse derived fuel (RDF), without adverse effects, due to the volatilization of Cl and an additional process of contaminated water.
Afficher plus [+] Moins [-]Bacterial contamination of drinking water and food utensils: Impacts of piped water on child health in north-western Bangladesh Texte intégral
2017
Hasan, Mohammad Monirul | Gerber, Nicolas
We investigate the impacts of access to piped water on drinking water quality, sanitation, hygiene and health outcomes in marginalized rural households of north-western Bangladesh, using a quasi-experimental setup. A government organization – the Barindra Multipurpose Development Authority (BMDA) – established a piped water network to connect rural households with the deep ground water resources and improve their access to potable water. Using propensity score matching, the study compares a treatment and a control group of households to identify gains in water-sanitation, hygiene and health outcomes. In terms of water safety, we find no improvement in the quality of drinking water, measured by E. coli count per 100 ml of water at the point of use (i.e. the pots and jars used to store it). Food utensils tested positive for E. coli in both the control and treatment group, thus showing no improvement through the BMDA intervention. Hygiene behavior such as handwashing with soap after defecation or before feeding children also does not improve. Finally, we do not find evidence of health benefits, such as decreased diarrhea incidence of under-five children or improved nutritional outcomes such as stunting, underweight and wasting. Although access to BMDA piped water in the premises is subject to a fee, it seems this incentive mechanism is not strong enough to improve water behavior or its outcomes: treated households are as poor as the non-treated in terms of maintaining hygiene and water quality, possibly because of lack of information.
Afficher plus [+] Moins [-]Rapid NMR determination of inorganic cations in food matrices: Application to mineral water Texte intégral
2017
Monakhova, Yulia B. | Kuballa, Thomas | Tschiersch, Christopher | Diehl, Bernd W.K.
A nuclear magnetic resonance (NMR) method was developed to quantify cations in mineral water. The procedure was based on integration of signals from metal-ethylenediaminetetraacetic acid (EDTA) complexes at δ 2.70ppm for Mg2+ and δ 2.56ppm for Ca2+. The limits of detection were below 0.5mg/L. Lack of precision did not exceed 5%. Linearity was between 1 and 500mg/L. Correlation between NMR and a reference chromatographic method was significant (p<0.0001, R2=0.99). PLS models were also established to estimate Na+ and K+ contents. R2 was 0.85 and 0.83, respectively. Root mean square errors of cross validation (RMSECV) were 8.0mg/L and 1.9mg/L for Na+ and K+, respectively. The method was applied successfully for the analysis of 31 mineral water samples. This method is a useful tool for quantification of important cations in mineral water and might easily be adapted to other food matrices.
Afficher plus [+] Moins [-]Understanding water-energy-food and ecosystem interactions using the nexus simulation tool NexSym Texte intégral
2017
Martinez-Hernandez, Elias | Leach, Matthew | Yang, Aidong
The water-energy-food (WEF) nexus concept highlights the importance of integrative solutions that secure resource supplies and meet demands sustainably. There is a need for translating the nexus concept into clear frameworks and tools that can be applied to decision making. A simulation and analytics framework, and a concomitant Nexus Simulation System (NexSym) is presented here. NexSym advances the state-of-the-art in nexus tools by explicit dynamic modelling of local techno-ecological interactions relevant to WEF operations. The modular tool integrates models for ecosystems, WEF production and consumption components and allows the user to build, simulate and analyse a “flowsheet” of a local system. This enables elucidation of critical interactions and gaining knowledge and understanding that supports innovative solutions by balancing resource supply and demand and increasing synergies between components, while maintaining ecosystems. NexSym allowed assessment of the synergistic design of a local nexus system in a UK eco-town. The design improved local nutrient balance and meets 100% of electricity demand, while achieving higher carbon capture and biomass provisioning, higher water reuse and food production, however with a remarkable impact on land use.
Afficher plus [+] Moins [-]Integrated modeling approach for optimal management of water, energy and food security nexus Texte intégral
2017
Zhang, Xiaodong | Vesselinov, Velimir V
Water, energy and food (WEF) are inextricably interrelated. Effective planning and management of limited WEF resources to meet current and future socioeconomic demands for sustainable development is challenging. WEF production/delivery may also produce environmental impacts; as a result, green-house-gas emission control will impact WEF nexus management as well. Nexus management for WEF security necessitates integrated tools for predictive analysis that are capable of identifying the tradeoffs among various sectors, generating cost-effective planning and management strategies and policies. To address these needs, we have developed an integrated model analysis framework and tool called WEFO. WEFO provides a multi-period socioeconomic model for predicting how to satisfy WEF demands based on model inputs representing productions costs, socioeconomic demands, and environmental controls. WEFO is applied to quantitatively analyze the interrelationships and trade-offs among system components including energy supply, electricity generation, water supply-demand, food production as well as mitigation of environmental impacts. WEFO is demonstrated to solve a hypothetical nexus management problem consistent with real-world management scenarios. Model parameters are analyzed using global sensitivity analysis and their effects on total system cost are quantified. The obtained results demonstrate how these types of analyses can be helpful for decision-makers and stakeholders to make cost-effective decisions for optimal WEF management.
Afficher plus [+] Moins [-]Insight-Based Approach for the Design of Integrated Local Food-Energy-Water Systems Texte intégral
2017
Leung Pah Hang, Melissa Yuling | Martinez-Hernandez, Elias | Leach, Matthew | Yang, Aidong
Society currently relies heavily on centralized production and large scale distribution infrastructures to meet growing demands for goods and services, which causes socioeconomic and environmental issues, particularly unsustainable resource supply. Considering local production systems as a more sustainable alternative, this paper presents an insight-based approach to the integrated design of local systems providing food, energy, and water to meet local demands. The approach offers a new hierarchical and iterative decision and analysis procedure incorporating design principles and ability to examine design decisions, in both synthesis of individual yet interconnected subsystems and integrated design of resource reuse across the entire system. The approach was applied to a case study on design of food-energy-water system for a locale in the U.K.; resulting in a design which significantly reduced resource consumption compared to importing goods from centralized production. The design process produced insights into the impact of one decision on other parts of the problem, either within or across different subsystems. The result was also compared to the mathematical programming approach for whole system optimization from previous work. It was demonstrated that the new approach could produce a comparable design while offering more valuable insights for decision makers.
Afficher plus [+] Moins [-]Cellular water distribution, transport, and its investigation methods for plant-based food material Texte intégral
2017
Khan, Md. Imran H. | Karim, M.A.
Heterogeneous and hygroscopic characteristics of plant-based food material make it complex in structure, and therefore water distribution in its different cellular environments is very complex. There are three different cellular environments, namely the intercellular environment, the intracellular environment, and the cell wall environment inside the food structure. According to the bonding strength, intracellular water is defined as loosely bound water, cell wall water is categorized as strongly bound water, and intercellular water is known as free water (FW). During food drying, optimization of the heat and mass transfer process is crucial for the energy efficiency of the process and the quality of the product. For optimizing heat and mass transfer during food processing, understanding these three types of waters (strongly bound, loosely bound, and free water) in plant-based food material is essential. However, there are few studies that investigate cellular level water distribution and transport. As there is no direct method for determining the cellular level water distributions, various indirect methods have been applied to investigate the cellular level water distribution, and there is, as yet, no consensus on the appropriate method for measuring cellular level water in plant-based food material. Therefore, the main aim of this paper is to present a comprehensive review on the available methods to investigate the cellular level water, the characteristics of water at different cellular levels and its transport mechanism during drying. The effect of bound water transport on quality of food product is also discussed. This review article presents a comparative study of different methods that can be applied to investigate cellular water such as nuclear magnetic resonance (NMR), bioelectric impedance analysis (BIA), differential scanning calorimetry (DSC), and dilatometry. The article closes with a discussion of current challenges to investigating cellular water.
Afficher plus [+] Moins [-]Managing the ecological limits to food, water and health security: The Asia Pacific Texte intégral
2017
M.L. Wahlqvist
Water production from food processing wastewaters using integrated membrane systems: A sustainable approach Texte intégral
2017
Castro-Muñoz, Roberto | Fíla, Vlastimil | Rodríguez-Romero, Víctor M. | Yáñez-Fernández, Jorge
Abstract: This scientific note reviews current approaches for using membrane technology to treat wastewater from food processing, for example, as a means to produce water by recovering components with high added value. In addition, with regard to the availability of wastewater, processes that contain membranes have been shown to be advantageous in terms of treating waste, recovering solutes, and producing water. With regard to the latter, processes that contain membranes can be considered to be a sustainable methodology given the valorization of waste. Lastly, this note provides a brief general view emphasizing a real need to apply membrane technology in the food industry, and indicates that its application is undoubtedly to come. | Resumen: Esta nota científica revisa los enfoques actuales de la tecnología de membranas para el tratamiento de residuos del procesamiento de alimentos; por ejemplo, como vía para la producción de agua a través de la recuperación de componentes de alto valor agregado. Además, se ha demostrado que los procesos integrados de membrana pueden ofrecer la ventaja de realizar las siguientes tareas en términos de disposición de aguas residuales: tratamiento de residuos, recuperación de solutos y producción de agua. Esto último permite considerar a los procesos integrados de membrana como una metodología sustentable a través de la valorización de residuos. Por último, esta nota provee una breve visión general, resaltando que la aplicación de la tecnología de membranas en verdad es necesaria en la industria alimentaria y que seguramente su implementación real aún está por venir.
Afficher plus [+] Moins [-]Water production from food processing wastewaters using integrated membrane systems: A sustainable approach Texte intégral
2017
Roberto Castro-Muñoz | Vlastimil Fíla | Víctor M. Rodríguez-Romero | Jorge Yáñez-Fernández
Castro-Muñoz, R., Fíla, V., Rodríguez-Romero, V. M., & Yáñez-Fernández, J. (November-December, 2017). Water production from food processing wastewaters using integrated membrane systems: A sustainable approach. Water Technology and Sciences (in English), 8(6), 129-136, DOI: 10.24850/j-tyca-2017-06-09. This scientific note reviews current approaches for using membrane technology to treat wastewater from food processing, for example, as a means to produce water by recovering components with high added value. In addition, with regard to the availability of wastewater, processes that contain membranes have been shown to be advantageous in terms of treating waste, recovering solutes, and producing water. With regard to the latter, processes that contain membranes can be considered to be a sustainable methodology given the valorization of waste. Lastly, this note provides a brief general view emphasizing a real need to apply membrane technology in the food industry, and indicates that its application is undoubtedly to come.
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