946 resultados para Waste disposal.
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UC-70
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"S. 3410, a bill to establish a structure that will provide integrated knowledge and understanding of the ecological, social, and technological problems associated with air pollution, water pollution, solid waste disposal, general pollution, and degradation of the environment, and other related problems": p. 31-40.
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"National Reactor Testing Station"--Cover.
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Cover title.
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At head of title: Nuclear Waste Policy Act (Section 112).
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This paper presents an assessment of the technical and economic performance of thermal processes to generate electricity from a wood chip feedstock by combustion, gasification and fast pyrolysis. The scope of the work begins with the delivery of a wood chip feedstock at a conversion plant and ends with the supply of electricity to the grid, incorporating wood chip preparation, thermal conversion, and electricity generation in dual fuel diesel engines. Net generating capacities of 1–20 MWe are evaluated. The techno-economic assessment is achieved through the development of a suite of models that are combined to give cost and performance data for the integrated system. The models include feed pretreatment, combustion, atmospheric and pressure gasification, fast pyrolysis with pyrolysis liquid storage and transport (an optional step in de-coupled systems) and diesel engine or turbine power generation. The models calculate system efficiencies, capital costs and production costs. An identical methodology is applied in the development of all the models so that all of the results are directly comparable. The electricity production costs have been calculated for 10th plant systems, indicating the costs that are achievable in the medium term after the high initial costs associated with novel technologies have reduced. The costs converge at the larger scale with the mean electricity price paid in the EU by a large consumer, and there is therefore potential for fast pyrolysis and diesel engine systems to sell electricity directly to large consumers or for on-site generation. However, competition will be fierce at all capacities since electricity production costs vary only slightly between the four biomass to electricity systems that are evaluated. Systems de-coupling is one way that the fast pyrolysis and diesel engine system can distinguish itself from the other conversion technologies. Evaluations in this work show that situations requiring several remote generators are much better served by a large fast pyrolysis plant that supplies fuel to de-coupled diesel engines than by constructing an entire close-coupled system at each generating site. Another advantage of de-coupling is that the fast pyrolysis conversion step and the diesel engine generation step can operate independently, with intermediate storage of the fast pyrolysis liquid fuel, increasing overall reliability. Peak load or seasonal power requirements would also benefit from de-coupling since a small fast pyrolysis plant could operate continuously to produce fuel that is stored for use in the engine on demand. Current electricity production costs for a fast pyrolysis and diesel engine system are 0.091/kWh at 1 MWe when learning effects are included. These systems are handicapped by the typical characteristics of a novel technology: high capital cost, high labour, and low reliability. As such the more established combustion and steam cycle produces lower cost electricity under current conditions. The fast pyrolysis and diesel engine system is a low capital cost option but it also suffers from relatively low system efficiency particularly at high capacities. This low efficiency is the result of a low conversion efficiency of feed energy into the pyrolysis liquid, because of the energy in the char by-product. A sensitivity analysis has highlighted the high impact on electricity production costs of the fast pyrolysis liquids yield. The liquids yield should be set realistically during design, and it should be maintained in practice by careful attention to plant operation and feed quality. Another problem is the high power consumption during feedstock grinding. Efficiencies may be enhanced in ablative fast pyrolysis which can tolerate a chipped feedstock. This has yet to be demonstrated at commercial scale. In summary, the fast pyrolysis and diesel engine system has great potential to generate electricity at a profit in the long term, and at a lower cost than any other biomass to electricity system at small scale. This future viability can only be achieved through the construction of early plant that could, in the short term, be more expensive than the combustion alternative. Profitability in the short term can best be achieved by exploiting niches in the market place and specific features of fast pyrolysis. These include: •countries or regions with fiscal incentives for renewable energy such as premium electricity prices or capital grants; •locations with high electricity prices so that electricity can be sold direct to large consumers or generated on-site by companies who wish to reduce their consumption from the grid; •waste disposal opportunities where feedstocks can attract a gate fee rather than incur a cost; •the ability to store fast pyrolysis liquids as a buffer against shutdowns or as a fuel for peak-load generating plant; •de-coupling opportunities where a large, single pyrolysis plant supplies fuel to several small and remote generators; •small-scale combined heat and power opportunities; •sales of the excess char, although a market has yet to be established for this by-product; and •potential co-production of speciality chemicals and fuel for power generation in fast pyrolysis systems.
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An integrated production–recycling system is investigated. A constant demand can be satisfied by production and recycling. The used items might be bought back and then recycled. The not recycled products are disposed off. Two types of models are analyzed. The first model examines and minimizes the EOQ related cost. The second model generalizes the first one by introducing additionally linear waste disposal, recycling, production and buyback costs. This basic model was examined by the authors in a previous paper. The main results are that a pure strategy (either production or recycling) is optimal. This paper extends the model for the case of quality consideration: it is asked for the quality of the bought back products. In the former model we have assumed that all returned items are serviceable. One can put the following question: Who should control the quality of the returned items? If the suppliers examine the quality of the reusable products, then the buyback rate is strongly smaller than one, α<1. If the user does it, then not all returned items are recyclable, i.e. the use rate is smaller than one, δ<1. Which one of the control systems are more cost advantageous in this case?
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Two deep-well injection sites in south Florida, USA, inject an average of 430 million liters per day (MLD) of treated domestic fresh wastewater into a deep saline aquifer 900 m below land surface. Elevated levels of NH3 (highest concentration 939 µmol) in the overlying aquifer above ambient concentrations (concentration less than 30 µmol) were evidence of the upward migration of injected fluids. Three pathways were distinguished based on ammonium, chloride and bromide ratios, and temperature. At the South District Wastewater Treatment Plant, the tracer ratios showed that the injectate remained chemically distinct as it migrated upwards through rapid vertical pathways via density-driven buoyancy. The warmer injectate (mean 28°C) retained the temperature signal as it vertically migrated upwards; however, the temperature signal did not persist as the injectate moved horizontally into the overlying aquifers. Once introduced, the injectate moved slowly horizontally through the aquifer and mixed with ambient water. At the North District Wastewater Treatment Plant, data provide strong evidence of a one-time pulse of injectate into the overlying aquifers due to improper well construction. No evidence of rapid vertical pathways was observed at the North District Wastewater Treatment Plant.
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Tailings dams are structures that aims to retain the solid waste and water from mining processes. Its analysis and planning begins with searching of location for deployment, step on which to bind all kinds of variables that directly or indirectly influence the work, such as geological, hydrological, tectonic, topographic, geotechnical, environmental, social characteristics, evaluation security risks, among others. Thus, this paper aims to present a study on the most appropriate and secure type of busbar to design a layout structure of iron ore tailings, taking into account all the above mentioned variables. The case study involves the assessment of sites for location of dams of tailings disposal beneficiation of iron mine to be built in Bonito, in the municipality of Jucurutu in Seridó Potiguar. For site selection among alternatives, various aspects of the current state of the art were considered, one that causes the least environmental impact, low cost investment, adding value to the product and especially the safety of the implanted structure mitigates the concern about induced earthquakes as a result of liquefaction wastes somatized by dams in the region, as the tilling of Mina Bonito is located practically in the hydraulic basin dam Armando Ribeiro in environmental protection (APA). The methodology compares induced by dams in the semiarid region with the characteristics of the waste disposal and sterile seismicity, taking into account the enhancement of liquefaction by the action of seismicity in the Mina Bonito region. With the fulcrum in the methodology, we indicated the best busbar type for disposal of tailings from iron ore or combination of them, to be designed and built in semiarid particularly for Mina Bonito. Also presents a number of possible uses for the tailings and in engineering activities, which may cause processing to the common good.
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rates in the Brazilian cities, which time there is an inexistent theoretical reflection about public policy statement adding the way of Urban Solid Waste (USW) and tailing integrated management plans in the majorly Brazilian cities. The unappropriated solid waste disposal and final pollution result in a strong socioenvironmental problems and material extravagancies that should be used to recycling and reusing waste material, besides bringing immense challenges for the thematic Strategy Urban and Environmental Management it considers the Sustainable City Model. Moreover, this labor projects a discussion about USW problematic through legally and environmentally point of view, including the public environmental policy and the social technologies as resolution tactics. At that time, it reports rights, scientific articles, documents and Environmental Law Doctrine on findings thematic studies, also the propose displays an interdisciplinary research methodology which combines bibliographic method - focusing theory aspects of the legally environmentally guiding principle, public policy and social technologies. Those are theorist features very important to create a Municipal Integrated Solid Waste Management Plan (PMGIRS) - modus operandi of the Federal Law n. 12.305/2010 (National Solid Waste Policy - PNRS). That policy is interesting to receive financial resources from federal government (Cities Ministry; idem, Federal Decree n. 7.404/2010 and Federal Law n. 10.257/2001) helping the preservation of the environment, regional development, generation of jobs and income (art. 6º), in addition broadening spreading’s private companies dedicated to waste management. Consequently, the PNRS contains a set of guidelines and general procedures; it should be an operation of this legal policy contextualized by Social Technologies theory (TS) into social issues, legal, economic and environmental aspects. Therefore, this research notes the possibility of public policy statement implementation over and done with the PNRS by the terms of development and sustainability in the urban space.
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From futures research, pattern recognition algorithms, nuclear waste disposal and surveillance technologies, to smart weapons systems, contemporary fiction and art, this book shows that we are now living in a world imagined and engineered during the Cold War. Drawing on theorists such as Jean Baudrillard, Jacques Derrida, Michel Foucault, Luce Irigaray, Friedrich Kittler, Michel Serres, Peter Sloterdijk, Carl Schmitt, Bernard Stiegler and Paul Virilio this collection makes connections between Cold War material and conceptual technologies, as they relate to the arts, society, and culture.
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The Pico de Navas landslide was a large-magnitude rotational movement, affecting 50x106m3 of hard to soft rocks. The objectives of this study were: (1) to characterize the landslide in terms of geology, geomorphological features and geotechnical parameters; and (2) to obtain an adequate geomechanical model to comprehensively explain its rupture, considering topographic, hydro-geological and geomechanical conditions. The rupture surface crossed, from top to bottom: (a) more than 200 m of limestone and clay units of the Upper Cretaceous, affected by faults; and (b) the Albian unit of Utrillas facies composed of silty sand with clay (Kaolinite) of the Lower Cretaceous. This sand played an important role in the basal failure of the slide due to the influence of fine particles (silt and clay), which comprised on average more than 70% of the sand, and the high content presence of kaolinite (>40%) in some beds. Its geotechnical parameters are: unit weight (δ) = 19-23 KN/m3; friction angle (φ) = 13º-38º and cohesion (c) = 10-48 KN/m2. Its microstructure consists of accumulations of kaolinite crystals stuck to terrigenous grains, making clayey peds. We hypothesize that the presence of these aggregates was the internal cause of fluidification of this layer once wet. Besides the faulted structure of the massif, other conditioning factors of the movement were: the large load of the upper limestone layers; high water table levels; high water pore pressure; and the loss of strength due to wet conditions. The 3D simulation of the stability conditions concurs with our hypothesis. The landslide occurred in the Recent or Middle Holocene, certainly before at least 500 BC and possibly during a wet climate period. Today, it appears to be inactive. This study helps to understand the frequent slope instabilities all along the Iberian Range when facies Utrillas is present.