21,405 research outputs found

    Assessment of regional trade and virtual water flows in China

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    The success of China's economic development has left deep marks on resource availability and quality. Some regions in China are relatively poor with regards to water resources. This problem is exacerbated by economic growth. Flourishing trade activities on both domestic and international levels have resulted in significant amounts of water withdrawal and water pollution. Hence the goal of this paper is to evaluate the current inter-regional trade structure and its effects on water consumption and pollution via ‘virtual water flows’. Virtual water is the water embedded in products and used in the whole production chain, and that is traded between regions or exported to other countries. For this assessment of trade flows and effects on water resources, we have developed an extended regional input–output model for eight hydro-economic regions in China to account for virtual water flows between North and South China. The findings show that the current trade structure in China is not very favorable with regards to water resource allocation and efficiency. North China as a water scarce region virtually exports about 5% of its total available freshwater resources while accepting large amounts of wastewater for other regions' consumption. By contrast, South China a region with abundant water resources is virtually importing water from other regions while their imports are creating waste water polluting other regions' hydro-ecosystems

    Recovery of Agricultural Nutrients from Biorefineries

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    This review lays the foundation for why nutrient recovery must be a key consideration in design and operation of biorefineries and comprehensively reviews technologies that can be used to recover an array of nitrogen, phosphorus, and/or potassium-rich products of relevance to agricultural applications. Recovery of these products using combinations of physical, chemical, and biological operations will promote sustainability at biorefineries by converting low-value biomass (particularly waste material) into a portfolio of higher-value products. These products can include a natural partnering of traditional biorefinery outputs such as biofuels and chemicals together with nutrient-rich fertilizers. Nutrient recovery not only adds an additional marketable biorefinery product, but also avoids the negative consequences of eutrophication, and helps to close anthropogenic nutrient cycles, thereby providing an alternative to current unsustainable approaches to fertilizer production, which are energy-intensive and reliant on nonrenewable natural resource extraction

    Total Value of Phosphorus Recovery

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    Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies

    Directory of Water Related Courses Offered at Colleges and Universities in Arkansas as of November 1998

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    This publication lists the water and water-related courses at several universities and colleges in Arkansas as reported during the Fall of 1 998. It is anticipated that users of this directory will extend beyond college students, and will include professionals seeking continuing education, and professors desiring to exchange Information on courses. This directory is not an absolute source of water and water-related courses because all of the higher learning Institutions In Arkansas are not listed, and, secondly, because the definition of water and water-related varies from institution to institution. None-the-less this directory provides a very valuable and impressive reference on water resources courses. Users must remember that course offerings, titles, and content change; therefore, one must contact the department to confirm details about each course. We are very grateful to the many people, too numerous to list, who have cooperated in gathering the Information In this second edition of the directory

    Biomass resources and biofuels potential for the production of transportation fuels in Nigeria

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    Solid biomass and waste are major sources of energy. They account for about 80% of total primary energy consumed in Nigeria. This paper assesses the biomass resources (agricultural, forest, urban, and other wastes) available in Nigeria and the potential for biofuel production from first, second, third and fourth generation biomass feedstocks. It reviews the scope of biomass conversion technologies tested within the country and the reports on the technology readiness level of each. Currently, most of the emerging biofuels projects in Nigeria utilize first generation biomass feedstock for biofuel production and are typically located many miles away from the petroleum refineries infrastructures. These feedstocks are predominantly food crops and thus in competition with food production. With significant availability of non-food biomass resources, particularly in the Niger Delta region of Nigeria, and the petroleum refineries located in the same area, it is pertinent to consider expanding use of the petroleum refinery׳s infrastructure to co-process non-food biomass into bio-intermediate oil for blending with petroleum. This not only addresses the potential food versus fuel conflict challenging biofuel production in Nigeria, but also reduces the cost of setting up new bio-refineries thus eliminating the transportation of ethanol to existing petroleum refineries for blending. In view of this, it is recommended that further research be carried out to assess the feasibility of upgrading existing refineries in Nigeria to co-process bio-based fuels and petroleum products thus achieving the targets set by the Nigeria Energy Commission for biofuel production in the country

    Water and Nutrition: Harmonizing actions for the United Nations Decade of Action on Nutrition and the United Nations Water Action Decade

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    Progress for both SDG 2 and SDG 6 has been unsatisfactory, with several indicators worsening over time, including an increase in the number of undernourished, overweight and obese people, as well as rapid increases in the number of people at risk of severe water shortages. This lack of progress is exacerbated by climate change and growing regional and global inequities in food and water security, including access to good quality diets, leading to increased violation of the human rights to water and food. Reversing these trends will require a much greater effort on the part of water, food security, and nutrition communities, including stronger performances by the United Nations Decade of Action on Nutrition and the United Nations International Decade for Action on Water for Sustainable Development. To date, increased collaboration by these two landmark initiatives is lacking, as neither work program has systematically explored linkages or possibilities for joint interventions. Collaboration is especially imperative given the fundamental challenges that characterize the promotion of one priority over another. Without coordination across the water, food security, and nutrition communities, actions toward achieving SDG2 on zero hunger may contribute to further degradation of the world’s water resources and as such, further derail achievement of the UN Decade of Action on Water and SDG 6 on water and sanitation. Conversely, actions to enhance SDG 6 may well reduce progress on the UN Decade of Action on Nutrition and SDG 2. This paper reviews these challenges as part of a broader analysis of the complex web of pathways that link water, food security and nutrition outcomes. Climate change and the growing demand for water resources are also considered, given their central role in shaping future water and nutrition security. The main conclusions are presented as three recommendations focused on potential avenues to deal with the complexity of the water-nutrition nexus, and to optimize outcomes

    A Framework for analyzing socioeconomic, health and environmental impacts of wastewater use in agriculture in developing countries

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    Waste water management / Environmental degradation / Waterborne diseases / Water quality / Irrigation practices / Aquaculture / Economic analysis / Social aspects / Health / Environmental aspects / Agriculture / Developing countries / Policy

    Sustainable Management of Food Supply-Chain Resources in New York State

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    A sustainable food supply chain (FSC) is at the nexus of several critical global challenges including hunger, resource scarcity, climate change, poverty, energy security and economic growth. However, managing FSC resources in a sustainable manner is complex and data to support this goal is lacking. This dissertation addressed four knowledge gaps by applying a variety of analytical and experimental tools to the New York State FSC. First, a cradle-to-grave analysis of the New York State FSC was conducted. Resources leaving the FSC from primary production (post-harvest) through to consumption were defined and characterized. Surveys and literature were used to estimate FSC resources and factors were provided for several sectors and sub-sectors including the Educational sector. Material flows through the utilization pathways in New York State were analyzed. It was estimated that over 3.5 million t/yr of solid resources were generated. Resource utilization pathways including donation were estimated to treat approximately 6% of these resources. An additional 22 million m3/yr of low solid resources primarily from the food processors was also estimated and analyzed. In the next chapter, climate change impacts of utilization pathways emerging in the State were analyzed. Two comprehensive lifecycle assessments (LCAs) were conducted to assess climate change impacts. The first was based upon primary data collected from the largest on-farm anaerobic digester in the State, which co-digests dairy manure and industrial food wastes. The results showed a net negative climate change of 37.5 kg CO2e/t influent processed when compared to the reference case. Displacement of grid electricity provided the largest reduction, followed by avoidance of alternative food waste disposal options and reduced impacts associated with storage of digestate vs. undigested manure. Sensitivity analysis showed that using feedstock diverted from high impact disposal pathways, control of digester emissions, and managing digestate storage emissions were opportunities to improve climate change benefits. The second LCA was based upon a small-scale, distributed waste-to-ethanol process. This analysis was based upon data from an operating pilot plant facility, co-fermenting industrial and retail FSC resources. The climate change impacts for the processing phase were estimated to be comparable to those associated commercial ethanol production, however when considering the avoidance waste disposal for FSC resources used as feedstock, the result was a net negative impact of 338 kg CO2e/MJ fuel produced. The following chapter evaluated the potential of several significant New York State FSC resources as feedstock for biogas production. Twenty-four source-separated, commercial substrates from the retail and food processing sector were characterized and tested in bench-scale bio-methane potential (BMP) tests. Substrates were also combined with dairy manure and other substrates to assess synergistic or antagonistic effects associated with co-digestion. Key bio-methane kinetic parameters including bio-methane potential, apparent hydrolysis rate constant and co-digestion indices were reported. Substrates with high fat content demonstrated higher potential for bio-methane generation. Substrates rich in readily hydrolysable carbohydrates and fats showed more complete bio-degradation. Measured bio-methane potential was the product of both of these factors. Bio-methane production of co-digested substrates was close to that of the weighted average of the individual substrates with a slight synergistic bias (-5%/+20% on average). However, co-digestion generally resulted in an increase in apparent hydrolysis rate relative to that predicted by the combination of individual substrates

    Water in the Green Economy: Capacity Development Aspects

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    This book discusses needs related to capacity development for water resources management, including water supply and sanitation, in the context of the green economy. It showcases theoretical and practical approaches with proven success. Most contributions come from members and partners within the interagency mechanism, UN-Water. The 11 case studies in this book range from innovative design and delivery of capacity development programs related to water in the green economy, market mechanisms, and quality control procedures supporting capacity development success towards the practical implementation of programs to enhance individual and institutional capacity
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