A comparative assessment of waste incinerators in the UK

The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87–92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management.     

California households' willingness to pay for ‘green’ electronics

Concerns about rapid increases in the volume of electronic waste (e-waste) and its potential toxicity have sharpened policy makers' interest for extended producer responsibility to encourage manufacturers of consumer electronic devices (CEDs) to ‘design for the environment’. This paper examines consumer willingness to pay for ‘green’ electronics based on a 2004 mail survey of California households. Using ordered logit models, it was found that significant predictors of willingness to pay for ‘greener’ computers and cell phones include age, income, education, beliefs about the role of government for improving environmental quality, as well as environmental attitudes and behaviors, but neither gender nor political affiliation. Although most respondents are willing to pay only a 1% premium for ‘greener’ CEDs, innovation and EU directives may soon make them competitive with conventional CEDs.     

取代尼罗河的作用:人为的营养物质在提供过去由一条大河带给地中海的肥力吗?

在1965年阿斯旺高坝合龙之前,尼罗河滋养着两个沙漠--一个陆地性的,一个海洋性的.每年的洪水在提供水和富营养的沉积物以维持尼罗河河谷洪泛区和河流三角洲中生命方面的作用明显地反映在埃及农业的悠久历史[1-3]和早期的卫星图像中[4].历史上尼罗河洪水对埃及沿岸地中海的生产力的影响也许不太普遍被人们察觉到,但这种影响是引人注目的[5-7].     

Use of waste materials in the construction industry

The authors summarize the results of an International Symposium by Correspondence on the use of waste and by-product materials in the construction industry which was recently organized by the Building Research Establishment (BRE) on behalf of the Réunion Internationale des Laboratoires d'Essais et de Recherches sur les Matériaux et les Constructions (RILEM). Information on the production and use of the more important wastes is tabulated and the main findings and national trends are discussed.     

Planning methodology for predicting spatial patterns of risk potential from industrial land uses

The nature of environmental risk is often determined by the location patterns of industrial firms in a locale. We develop a methodology for analyzing the capacity of toxics-generating industries to leave toxic residuals on the landscape, in the context of long-term master planning. To understand an area's risk profile, we first characterize the location pattern of risk-generating firms and develop ways to represent the risk potentials of these shapes. To this end, we develop a geometric approach for characterizing the spatial patterns of these clusters of dirty industries, using new measures for analyzing spatial densities and compactness. We then introduce context (i.e. actual zoning patterns, transportation corridors) and explain how this relates to the spatial patterns found. We illustrate this analytical method with application to Orange County, California, USA and point out how it affords a deeper understanding of the connections between industry and environmental risk. We end the article with a discussion of how these analytical methods might be used for land use planning.