63,334 research outputs found

    Fresh Water and Smarter Growth: Restoring Healthy Land-water Connections

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    The paper describes water resources in the United States, discusses the principles of the land-water connection, outlines the current regulatory framework, and explains the impact of climate change. It also introduces the concept of low impact development while providing examples, and highlights how funders are having an impact on sustainable water management. With bibliographical references

    Building the Blue Economy: Opportunities for Community-Based Organizations in Stormwater Management

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    The United States has a serious problem with combined sewer overflows. In responding to this environmental and public health menace, many regions are using innovative “green infrastructure” or “blue economy” approaches in addition to traditional “gray infrastructure” such as pipes and reservoirs. These new methods offer many environmental benefits and cost efficiencies and can be a potent source of jobs – including entry level jobs. This report outlines ways for community-based organizations to seize these opportunities, both by advocating for green infrastructure and by developing social enterprises that do stormwater management work at a neighborhood level. It is designed for non-profit groups, policy makers, and funders interested in the intersection of sustainability, neighborhood redevelopment, and job creation and the possibility of a triple win in all three areas

    Towards more ecoefficient food production: MFA approach

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    The food flux comprises four mutually linked loops: 1)plant production, 2)livestock husbandry, 3) food processing industry and 4) human consumption. In the present paper MFA approach has been used to describe the system. A general framework and practical solutions for estimating and balancing the materials flow are outlined. The focus in this paper is agriculture

    Urban Evolution: The Role of Water

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    The structure, function, and services of urban ecosystems evolve over time scales from seconds to centuries as Earth’s population grows, infrastructure ages, and sociopolitical values alter them. In order to systematically study changes over time, the concept of “urban evolution” was proposed. It allows urban planning, management, and restoration to move beyond reactive management to predictive management based on past observations of consistent patterns. Here, we define and review a glossary of core concepts for studying urban evolution, which includes the mechanisms of urban selective pressure and urban adaptation. Urban selective pressure is an environmental or societal driver contributing to urban adaptation. Urban adaptation is thesequential process by which an urban structure, function, or services becomes more fitted to its changing environment or human choices. The role of water is vital to driving urban evolution as demonstrated by historical changes in drainage, sewage flows, hydrologic pulses, and long-term chemistry. In the current paper, we show how hydrologic traits evolve across successive generations of urban ecosystems via shifts in selective pressures and adaptations over time. We explore multiple empirical examples including evolving: (1) urban drainage from stream burial to stormwater management; (2) sewage flows and water quality in response to wastewater treatment; (3) amplification of hydrologic pulses due to the interaction between urbanization and climate variability; and (4) salinization and alkalinization of fresh water due to human inputs and accelerated weathering. Finally, we propose a new conceptual model for the evolution of urban waters from the Industrial Revolution to the present day based on empirical trends and historical information. Ultimately, we propose that water itself is a critical driver of urban evolution that forces urban adaptation, which transforms the structure, function, and services of urban landscapes, waterways, and civilizations over time

    Municipal wastewater treatment with pond technology : historical review and future outlook

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    Facing an unprecedented population growth, it is difficult to overstress the assets for wastewater treatment of waste stabilization ponds (WSPs), i.e. high removal efficiency, simplicity, and low cost, which have been recognized by numerous scientists and operators. However, stricter discharge standards, changes in wastewater compounds, high emissions of greenhouse gases, and elevated land prices have led to their replacements in many places. This review aims at delivering a comprehensive overview of the historical development and current state of WSPs, and providing further insights to deal with their limitations in the future. The 21st century is witnessing changes in the way of approaching conventional problems in pond technology, in which WSPs should no longer be considered as a low treatment technology. Advanced models and technologies have been integrated for better design, control, and management. The roles of algae, which have been crucial as solar-powered aeration, will continue being a key solution. Yet, the separation of suspended algae to avoid deterioration of the effluent remains a major challenge in WSPs while in the case of high algal rate pond, further research is needed to maximize algal growth yield, select proper strains, and optimize harvesting methods to put algal biomass production in practice. Significant gaps need to be filled in understanding mechanisms of greenhouse gas emission, climate change mitigation, pond ecosystem services, and the fate and toxicity of emerging contaminants. From these insights, adaptation strategies are developed to deal with new opportunities and future challenges

    ZeroWasteWater: short-cycling of wastewater resources for sustainable cities of the future

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    Sewage treatment relies mainly on conventional activated sludge (CAS) systems, reaching sufficiently low pollutant effluent levels. Yet, CAS has a low cost-effectiveness and recovery potential and a high electricity demand and environmental footprint. By 2050, globally we have to solve severe water and phosphorus shortages while significantly decreasing greenhouse gas emissions. In this review and opinion paper, the ZeroWasteWater concept is proposed as a sustainable centralised technology train to short-cycle water, energy and valuable materials from sewage, while adequately abating pathogens, heavy metals and trace organics. Electrical energy recovery from anaerobic digestion of the organics present in sewage and kitchen waste (KW) has a value of 4.0 per inhabitant equivalent (IE) per year. In addition to sewerage improvements and water conservation, prerequisites include an advanced physico-chemical and/or biological concentration step at the entry of the sewage treatment plant. In the side stream, the recovery of phosphorus and carbon-sequestrating biochar from the digested sludge and of nitrogen from the digestate has a value of 6.3IE-1 year-1. Alternatively, recovery of biogas and materials can occur directly on source-separated black water. In the main stream, partial nitritation and anammox oxidise residual nitrogen. Moreover, two serial heat pumps recover thermal energy, valued at 6.9IE-1 year-1, cooling the water by 5 degrees C, and membrane technologies recover potable water at 65IE-1 year-1. Interestingly, ZeroWasteWater is expected to be economically viable. Key steps are to incorporate water chain management into holistic urban planning and thus produce a cradle-to-cradle approach that society will find acceptable

    A critical review of resource recovery from municipal wastewater treatment plants : market supply potentials, technologies and bottlenecks

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    In recent decades, academia has elaborated a wide range of technological solutions to recover water, energy, fertiliser and other products from municipal wastewater treatment plants. Drivers for this work range from low resource recovery potential and cost effectiveness, to the high energy demands and large environmental footprints of current treatment-plant designs. However, only a few technologies have been implemented and a shift from wastewater treatment plants towards water resource facilities still seems far away. This critical review aims to inform decision-makers in water management utilities about the vast technical possibilities and market supply potentials, as well as the bottlenecks, related to the design or redesign of a municipal wastewater treatment process from a resource recovery perspective. Information and data have been extracted from literature to provide a holistic overview of this growing research field. First, reviewed data is used to calculate the potential of 11 resources recoverable from municipal wastewater treatment plants to supply national resource consumption. Depending on the resource, the supply potential may vary greatly. Second, resource recovery technologies investigated in academia are reviewed comprehensively and critically. The third section of the review identifies nine non-technical bottlenecks mentioned in literature that have to be overcome to successfully implement these technologies into wastewater treatment process designs. The bottlenecks are related to economics and value chain development, environment and health, and society and policy issues. Considering market potentials, technological innovations, and addressing potential bottlenecks early in the planning and process design phase, may facilitate the design and integration of water resource facilities and contribute to more circular urban water management practices

    Towards more ecoefficient food production: MFA approach

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    The key for the sustainable development is dematerialisation and ecoefficiency. Applied to agriculture ecoefficiency means production of nutritionally better food by using less inputs and by reducing the environmental burden. In restricting the material throughput it is essential to identify the most voluminous material flows and to direct the measures to them. Improving ecoefficiency of the food production requires that the benefits and the inputs are quantified in an unambiguous way and that the inputs are estimated for the whole production chain. A comprehensive view of the whole system is necessary. The food system comprises four mutually linked loops: 1) the plant production 2) the livestock husbandry, 3) the food processing industry and 4) the human consumption. In the present paper MFA approach has been used to describe the system. A general framework for estimating and balancing the materials flow is outlined. The focus is on agriculture, specifically on the materials flow created by the biological metabolism of the animal husbandry. The holistic MFA approach provides means to evaluate environmental and economic consequences of the production. For the decision-makers the MFA approach is a tool to guide the development and to assess the progress towards increasing ecoefficiency within the food system. The results can be used in developing new sustainability indicators. Some of the possibilities are shortly discussed. The study is the first step in developing MFA methods to analyse and to monitor the materials flow of the Finnish food systems. It is a part of the project “The Materials Flow and Ecoefficiency of Agriculture and the Sustainable Compatibility of the Food Production” carried out in collaboration between the MTT - Agrifood Research Finland and the Thule Institute at the University of Oulu. The results are used also in compiling the Finnish physical input-output tables. The study, thus, contributes to the overall development of the materials flow accounting statistics

    Future Projections of Urban Waste Flows aand their Impacts in African Metropolises Cities

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    This paper presents future trends of urban wastes and their impacts on the environment of African cities using plausible mitigation scenarios. To accomplish this, an integrated dynamic model for urban waste flows was developed, tested, calibrated and validated. Its parameter sensitivity was analyzed. Using population projection up to 2052 with different levels of technological implementation, policy enforcement and awareness raising, four runs were executed. The “business as usual” run showed that with no additional mitigation measures, the environmental quality in Kampala and Dar es salaam Cities deteriorates. The “more enforcement” and “more collection” scenarios showed good reduction in environmental loads but they perform less well in resource recovery. The “proper management” scenario that combines enhanced technological implementation, awareness raising and policy enforcement, produced the smallest environmental loads, and recovered the largest amount of resources. Thus, the city authorities, general public, community based organisations and Non-governmental organizations would have to increase their efforts in finances and commitment to improve the urban environmental quality and increase resource recovery
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