Recycling opportunities in the UK for aluminium-bodied motor cars

The purpose of this paper is to review, and draw attention to, issues raised by the recycling of wrought aluminium from motor cars, even though the time horizon for significant arisings of such aluminium scrap is in the order of 20 years from now. Recycling of specific grades of wrought aluminium will be viable only when a means of positively identifying different types of scrap is available. A solution must be reliable, rapid, and low-cost; probably used in conjunction with a vehicle shredder. Such a system of identification will eliminate the need for costly hand-dismantling and segregation. Simple segregation of cast and wrought alloy will, however, be essential when wrought aluminium from car bodies dominates the scrap arisings. Such segregation will produce two high-value scrap products. The first of which will be similar to the A380 casting alloy specification, maintaining the current supply of this scrap, and the second will be a composite of wrought alloys. These issues are relevant to the aluminium scrap industry, which will have to accommodate future changes in the composition of the scrap it receives, and the motor industry, which may adopt in-house recycling of wrought alloy in order to offset the high purchase cost of aluminium.     

Electric power and the environment: an analysis of pollutant emissions at Argentine state-owned electric power stations

This paper describes the impact on particulate and 'greenhouse gases' emissions of substitution policies implemented by Argentine state-owned electric power stations. Those policies involve the substitution, on the one hand, of hydroelectric and nuclear energy for conventional thermal energy and, on the other hand, of natural gas for fuel oil, diesel oil and coal. As additional investments are required in conventional thermal power stations to prevent environmental pollution, the investment savings generated by substitution policies have been calculated. While the environmental impact of hydroelectric, nuclear and natural gas facilities is locally significant and is experienced in geographical areas away from cities, there can be no doubt that the substitution policies implemented in the Argentine electricity sector have overall both ecological and economic benefits.     

Reconstructing historical trends of Berre lagoon contamination from surface sediment datasets: influences of industrial regulations and anthropogenic silt inputs

These last decades, the Berre lagoon (in southeastern France) has been deeply affected since the 1930s by strong inputs of contaminants associated with industrial development and since 1966 by huge inputs of freshwater and silts due to the installation of a hydroelectric power plant. Surveys of the surface sediment contamination have been sparsely performed since 1964 for management and research purposes. These surveys were performed by various laboratories that investigated different chemicals and sampling areas using different analysis protocols. Therefore, the available data are disconnected in time and space and differ in quality. In order to reconstruct coherent time series of sediment contamination from this heterogeneous datasets and to discuss the influences of industrial and hydroelectric discharges we used a statistical approach. This approach is based on Principal Component Analysis (PCA) and Fuzzy clustering analysis on data from one extensive survey realized on surface sediments in 1976. The PCA allowed identifying two geochemical indexes describing the main surface sediment geochemical characteristics. The fuzzy clustering analysis on these indexes allowed identifying sub-areas under the specific influence of industrial or hydroelectric discharges. This allowed us to reconstruct, for each sub-area, a coherent and interpretable long-term time series of sediment contamination from the available database. Reconstructed temporal trends allowed us to estimate: (i) the overall decrease of sediment contamination since the mid-1970 attributed to industrial discharge regulations enacted at this period and (ii) the dilution of the concentrations of sediment bound contaminants induced by the hydroelectric power plant and its associated particulate matter inputs.     

Determination of optimum minimum flow from a dam by using energy analysis

The proposed restoration of an abandoned hydroelectric dam on the Quinebaug River, Connecticut, is studied using energy analysis. The analysis considers the effects of alternative minimum flow releases, ranging from 0 to 34 cubic meters per second (cms), on the total energy flow of the affected system. The principal system components affected by differing minimum flows are hydroelectric power generation, aquatic habitat, and gross aquatic ecosystem productivity.The minimum flow alternative resulting in the highest annual energy flow in the affected system is considered optimal. From this purely analytical point of view, the optimum minimum flow is 0 cms, due to the short length and low productivity of the regulated reach, and the lack of floodplain interactions.Simulations of longer and more productive river reaches were conducted. For very short, unproductive reaches, in the absence of a floodplain, the contribution of aquatic community productivity to total system energy flow is negligible compared to hydroelectric generation. Optimum minimum flows are higher for longer and more productive reaches. For such cases the operation of hydroelectric dams could reduce total system energy flow because the energy supplied by hydroelectric generation may be offset by losses in aquatic productivity due to diminished riverine habitat.     

THE BUREAU OF RECLAMATION'S ROLE IN AMERICA'S GROWTH1

ABSTRACT. The Bureau of Reclamation was created to implement the Reclamation Act of 1902 and subsequent legislation to conserve and develop the water resources of the western states for maximum efficient use. This has been accomplished by the planning and construction of major multiple use projects which now supply water to approximately eight million acres of land which annually produce 52 million tons of food and fiber with a gross crop value of approximately $2 billion. Fifteen million people are served with municipal and industrial water supplies and hydroelectric power from Bureau projects now returns $160 million annually to the Treasury. Flood control, recreation, and fish and wildlife enhancement are other major benefits. The Bureau of Reclamation is now undertaking a Westwide Survey of water resources and of the needs of the future which is more far-reaching than anything heretofore accomplished. The information accumulated during this ten-year survey will determine whether there is a necessity for consideration of major interbasin transfer of water supply.     

Energy and environmental challenges for developed and developing countries

A supply-oriented strategy which accepts current projections of development energy demands, and seeks to satisfy them, based on acquiring capital-intensive technologies requiring imported fuels is doomed to failure. Developing countries which follow such a strategy will be unable to meet either their energy needs or the basic development needs of their people. To the extent that their energy needs are thus met, it will be at horrendous cost of capital desperately needed for economic and social improvement in non-energy sectors and with tragic environmental consequences to the developing countries and to the world [17]. The opposite of a supply-oriented strategy is a demand-control one. Commercially available or near commercial energy efficient technologies will permit the developing countries to raise the standard of living of their people with only a modest increase in per capita energy consumption.     

Ecosystem Manipulation Experimentation as a Means of Testing a Biogeochemical Model

2 concentration, and global or regional temperature change. Such model projections are frequently used as the basis or justification for public policy decisions and legislation. A substantial need has therefore arisen to test and substantiate the veracity of mathematical model projections. Unfortunately, environmental models can never be truly validated because natural systems are never closed and model solutions are always nonunique. Partial model confirmation is possible, however, and entails demonstration of agreement between prediction and observation. Experimental ecosystem manipulation provides one of the best, and in many cases only, available basis for model confirmation. The use and potential misuse of data from experimental ecosystem manipulations for model testing is explored using examples drawn from the application of an acid–base chemistry model, MAGIC. As model projections provide an increasingly important basis for public policy decisions, and as both the scientific questions and the models become increasingly complex, it will become critical to provide data from a suite of well-designed ecosystem manipulation experiments in order to evaluate the quality and uncertainty of those model projections and the models upon which they are based.     

岷江上游水电开发对环境的影响

岷江上游水力资源十分丰富，随着西部大开发的进行，它已成为水电开发的重点区域，干流及支流的电站建设加速进行。自源头至汶川上游河段，实行六级梯级开发方案。但由于岷江水电工程主要是涵洞引水式，原来奔腾的河流变成了地下暗流，使得岷江的多处河段变得干涸，河谷的自然生境和景观发生了很大的变化，原来的干旱河谷气候变得更加干旱。也使河流生物系统受到严重影响。作者在对长江上游考察的基础上对岷江上游水电开发现状及其对环境的影响进行了分析，提出应该进行流域统一规划，强化执法监督，水电开发与环境保护建设并重；加强上中下游统一管理，注重流域综合开发等建议。     

Private micro-hydro power and associated investments in Nepal: the Barpak village case and broader issues

This article examines a number of issues connected with the development of small-scale hydroelectric power and related investments in Nepal. The micro-hydro investment scheme in Barpak village serves as a case study, and the article also presents a number of related issues discussed against the background of the evolution of micro-hydro power in Nepal. The article outlines the success of micro-hydro development, modest in relation to its enormous potential, the realization of which depends on whether a number of challenges and constraints can be overcome. The article closes with suggestions on implementing sustainable micro-hydro development in rural areas, based on the Barpak experience and the authors' other recent studies of rural energy issues in Nepal.     

THE IMPACTS OF WATERWAY USER FEES ON GRAIN TRANSPORTATION ON THE SNAKE-COLUMBIA RIVER1

ABSTRACT: Grain transportation is a major economic activity on the multiple use Snake-Columbia River System. Congress is currently considering increased transportation user fees aimed at recapturing federal expenditures for waterway operations and maintenance. Three types of fee structure and four levels of cost recovery are evaluated using a network program model. In each case traffic is diverted away from the river to other Puget Sound ports via truck and rail transport modes. Grain shippers in the region will be adversely affected by a higher transport bill. The Lower Columbia River port economic activities will be negatively affected; however, competitive uses of the river, recreation, and hydroelectric generation will likely benefit modestly.     

A STOCHASTIC DYNAMIC PROGRAMMING BASED APPROACH TO THE OPERATION OF A MULTI-RESERVOIR SYSTEM1

ABSTRACT: An heuristic iterative technique based upon stochastic dynamic programming is presented for the analysis of the operation of a three reservoir ‘Y’ shaped hydroelectric system. The technique is initiated using historical inflow data for the downstream reservoir. At each iteration the optimal policies for the downstream hydroelectric generating unit are used to provide relative weightings or targets for operation of upstream reservoirs. New input inflows to the downstream reservoir are then obtained by running the historical streamflow record through the optimal policies for the upstream reservoirs. These flows are then used to develop a new operating policy for the downstream reservoir and hence new targets for the upstream reservoirs. The process is continued until the operating policies for each reservoir provide the same overall system benefit for two successive iterations. Results obtained from the procedure are compared to the results obtained by historical operation of the system. The procedure is shown to develop operating policies which give benefits which are as close to the historical benefits as can be expected given the choice of the number of storage state variables.     

Restructuring of the aluminium industry

In the 1980s, the basic strategies of the major integrated aluminium companies have been to emphasize added investment in downstream activities at the expense of investment in smelting and raw material supply. The paper examines the rationale for such investment strategies, explores the advantages and disadvantages of downstream investment and presents projections of future demand and capacity in the industry. Overall, the industry appears to be in good shape until the mid-1990s when demand is likely to exceed currently projected capacity.     

HYDROELECTRIC POWER AND SCENIC PROVISIONS OF THE 1950 NIAGARA TREATY1

ABSTRACT: An important international Niagara River management issue concerns allocation of the average 202,000 cubic feet per second river discharge for hydroelectric power and scenic purposes. Major water diversions from Niagara Falls are necessary for power production. Flow is allocated by the 1950 Niagara Treaty which is intended to maximize power benefits and preserve and enhance the scenic fals spectacle. This paper examines the extent to which the Treaty objectives have been achieved. Based on analyses of government documents, engineering data, and falls-viewing patterns, it is concluded that the 1950 Treaty led to enhancement of the falls spectacle and increased power generation. But significant additional power diversions probably are attainable without adverse effect upon the existing falls spectacle. Reducing daytime summer Horseshoe Falls flow and scheduling spring and autumn flow according to viewing patterns are possible means of increasing power diversions. Existing generating facilities could use considerably more water and the value of additional Niagara hydroelectricity is very high in terms of generation-cost savings over alternative power sources. Because of the cultural importance of the falls, Treaty modifications to permit increased power diversions are not recommended without prior public opinion sampling and on-site viewing experiments. These findings highlight the need for more careful study before long-term international agreements are concluded and illustrate the need for more flexible treaty arrangements to permit periodic adjustments for changing conditions.     

Hedging a Commodity Power Rate

Many of the aluminium smelters in the Pacific Northwest served by the Bonneville Power Administration (BPA) have become non-competitive and operate in the role of swing producer in the US and world markets. To avoid these cyclical swings in power demand, BPA is presently studying methods designed to link the price of power charged to smelters with the market price of aluminium. A linked-rate system tends to stabilize incomes to smelters, but increases fluctuations to the utility. These, in turn, could be stabilized by a hedging operation on the London Metals Exchange.     

The economics of uranium demand

The major characteristics of the demand for uranium are identified, and a number of factors which determine the actual level of uranium requirements of the nuclear power industry are discussed. Since the role of inventories is central to the process of short-term price formation, by comparing projections of uranium production and apparent consumption, the relative level of total inventories is calculated and an assessment is made of its likely impact on the uranium market during the 1980s.     

Acid surface waters: the prognosis for fish

Summary The extent of surface water acidification in Northern Europe and in Britain is reviewed and information is given on the degree to which changes in water quality appear to have influenced fish populations. The relationship between water quality and fish has been clarified by laboratory exposures, demonstrating that levels of calcium and aluminium, as well as acidity, are important for fish. It is not easy, however, to transpose laboratory findings to the field. Other determinants of a fishery should not be ignored — they include morphological and physical characteristics of lakes and streams, and biological characteristics such as food supply and species interactions.The recovery or restoration of fisheries in acid waters is crucially dependent on replacement of calcium and reduction of aluminium to bring the water quality into a range suitable for fish. While reduction of sulphur emissions, or of the atmospheric deposition of all acid generating materials, may be expected to have some effect on lake sulphate concentrations, the degree to which acidity might be realistically reduced is quite uncertain.Dr. G. D. Howells was, until recently, Head of Biology at the Central Electricity Research Laboratories of the United Kingdom's Central Electricity Generating Board (CEGB). Her previous experience includes her first degree, obtained in New Zealand, a subsequent research degree from the University of Cambridge, and three years at the University of New York studying the effects of power station siting on the Hudson River. She has a wide experience of studying pollution problems. This paper was presented at the Institution of Environmental Sciences Conference,An Update on Acid Rain, November 1984, and is published by permission of the Central Electricity Generating Board.     

Organizational and Political Considerations in the Municipal Development of Small Hydropower1

ABSTRACT: The potential for hydroelectric power development at existing dams is great in oil dependent New England where there are over 10,000 dams presently in existence. Over 400 developments have been proposed in the region, the majority of which are small scale, and do not have major environmental impacts. Nevertheless, a variety of constraints may hinder development. A study of three efforts by municipalities in unique positions to develop hydropower reveals that organizational and political considerations are significant factors affecting development. Successful hydropower development requires: (1) the cooperation and interaction of citizens, government, and the private sector; (2) community interest and education; and (3) strong resolve.     

A NEW CHALLENGE FOR WESTERN WATER SUPPLIES1

ABSTRACT: In many of the limited water resource areas of the western United States most water supplies have been put to beneficial uses. Energy, a fast expanding high-priority water use, is making challenging demands for these limited supplies. Can water supplies be stretched, supplemented, or redirected so that present uses can be maintained and energy water needs satisfied? The Bureau of Reclamation is investigating innovative methods of water management, reregulation, and use to meet these demands. Related programs under study include potentials for: development of additional hydroelectric power, installation of low-head turbines in western water courses, utilization of pumped storage and underground storage, use of geo-thermal heat, extension of water supplies through more efficient irrigation systems and practices, and weather modification.     

A study on operation problems of hydropower plants integrated with irrigation schemes operated in Turkey

In this study, Hydroelectric Power Plants, which have been built and integrated with irrigation schemes by the State Hydraulic Works which is a government agency and private companies in Turkey, have been examined. Technical, environmental, structural and social problems encountered during their operation have been analyzed, and appropriate solution proposals have been presented in the study for a sustainable irrigation and Hydroelectric Power Plant operation. Consequently, Hydroelectric Power Plants which have been integrated with irrigation schemes should be operated efficiently and they should be operated in attenuation with the environment. However, when hydroelectric projects are developed without preparing their necessary integrated basin management plans, then this will cause environmental, operation and maintenance, administrative, monitoring and evaluation problems. In order to ensure sustainability of hydroelectricity production and also in order to use water resources more efficiently for irrigation; it is very important to find permanent solutions to these problems.     

Review of pollutants removed by electrocoagulation and electrocoagulation/flotation processes

The word “electrocoagulation” (EC) will be sometimes used with “electroflotation” (EF) and can be considered as the electrocoagulation/flotation (ECF) process. Through the process of electrolysis, coagulating agents such as metal hydroxides are produced. When aluminium electrodes are used, the aluminium dissolves at the anode and hydrogen gas is released at the cathode. The coagulating agent combines with the pollutants to form large size flocs. As the bubbles rise to the top of the tank they adhere to particles suspended in the water and float them to the surface. In fact, a conceptual framework of the overall ECF process is linked to coagulant generation, pollutant aggregation, and pollutant removal by flotation and settling when it has been applied efficiently to various water and wastewater treatment processes. This review paper considers a significant number of common applications of EC and ECF processes which have been published in journal and conference papers.