Waste management of electric and electronic equipment: comparative analysis of end-of-life strategies

This article analyzes diverse aspects of the waste management of electronic and electric equipment. The scope of the study focuses on end-of-life strategies currently implemented in industrialized economies such as Japan, the United States, and the European Union. The objective is a comparative analysis of such strategies in order to identify logistic issues that may contribute to the further improvement of waste management policies. The results indicate that although all strategies follow the extended producer responsibility principle, in practice several logistic differences arise due to particular interpretations of the concept. In general, it was observed that a direct comparison is rather difficult since the strategies consider different legal frameworks, they cover different types and numbers of products, and the resultant mass flows and related operational costs are highly context-dependent variables. Therefore, it is not possible to indicate which strategy presents the highest overall efficiency. The study concludes that a little contribution is feasible if the advantages and weaknesses of the models depicted and discussed here are considered in further regulatory decisions.Extended version of the poster presentation A comparative analysis of end-of-life strategies for home appliances in Japan, America, and the European Union, accepted at the 31st Annual Meeting of Environmental Systems Research, Japan Society of Civil Engineers (JSCE), October 24–25, 2003, Kitakyushu, Japan     

粉煤灰综合利用研究进展

介绍了粉煤灰的物理化学性质。综述了粉煤灰在建材制造、建筑工程、道路工程、农业、废水处理和催化反应中的应用现状以厦未来的应用前景。     

医疗废物热解焚烧处理技术探讨

本文依据国内目前医疗废物的组成特性，对引进国外的医疗废物热解焚烧炉的技术特性及设计原则进行了阐述，并对其进行了优化设计。     

重庆市基于排放绩效的火电行业二氧化硫总量控制研究

本文介绍了排放绩效及排放绩效方法在火电行业二氧化硫总量控制方面的应用，并对重庆市火电机组及其二氧化硫排放状况进行了全面调查，根据重庆市二氧化硫污染防治的需要制定了各时段机组“十一五”期间的排放绩效控制标准，利用排放绩效方法测算了重庆市火电行业二氧化硫总量控制目标，提出了总量配额分配方法。     

RESIDUAL POWER AND ECONOMIC FEASIBILITY OF A SOLAR POWERED IRRIGATION SYSTEM1

ABSTRACT: The problem of nonmatching irrigation and solar power production seasons creates the problem of what to do with the surplus power. The economic law of opportunity cost dictates that substitution for currently commercially purchased power is the best use for this power. This law also allows for new power using enterprises that satisfy specific criteria to be used on the farm before sale of the residual to a local public utility can be considered. Economic and Financial Evaluation of the solar powered irrigation system show that the price of commercially purchased power must reach 9.5 cents per Kwh before the system is feasible under the ideal assumption of complete use of the residual power to substitute for commercially purchased power.     

A NONLINEAR PROGRAMMING ALGORITHM FOR REAL-TIME HOURLY RESERVOIR OPERATIONS1

ABSTRACT: The optimization of real-time operations for a single reservoir system is studied. The objective is to maximize the sum of hourly power generation over a period of one day subject to constraints of hourly power schedules, daily flow requirement for water supply and other purposes, and the limitations of the facilities. The problem has a nonlinear concave objective function with nonlinear concave and linear constraints. Nonlinear Duality Theorems and Lagrangian Procedures are applied to solve the problem where the minimization of the Lagrangian is carried out by a modified gradient projection technique along with an optimal stepsize determination routine. The dimension of the problem in terms of the number of variables and constraints is reduced by eliminating the 24 continuity equations with a special implicit routine. A numerical example is presented using data provided by the Bureau of Reclamation, Sacramento, California.     

GENERATION OF DAILY PRECIPITATION OVER AN AREA1

ABSTRACT: A model was developed of the periodic-stochastic structure of daily precipitation over an area. The model is based ona multivariate normal distribution. The square roots of daily precipitation at a point were found to approximate a sample from a univariate normal distribution that had been truncated at zero. The zero daily precipitation amounts were considered negative amounts of unknown quantity. The multivariate normal distribution was used to describe the variation of daily precipitation over an area. The periodic fluctuations of the model parameters were described with Fourier series. The model was tested using data from two areas of different precipitation characteristics. Data generated with the model contained many of the statistical characteristics observed in the historical data.     

火电厂"三同时"验收应当注意的问题

根据建设项目竣工环境保护验收规范要求，提出火电厂在验收过程中应当注意的几个问题。     

Evaluation of the effect of automotive bumper recycling by life-cycle inventory analysis

This paper describes a case study of the application of life-cycle inventory analysis to automotive bumper recycling. Two scenarios of bumper recycling are compared. One is “bumper-to-bumper recycling,” in which we recycle bumpers into more bumpers. The other is “cascade recycling,” in which bumpers are recycled into different parts of a car with a lower function. Inventory analysis is applied to both these recycling scenarios by analyzing the stages of acquiring natural resources, manufacturing materials, and parts, disposal, and recycling. We chose air emission, solid waste, and fossil fuel resources as items of the inventory analysis. We quantified the effect of reductions in the environmental load by recycling bumpers, and found that reductions in the environmental load were larger with cascade recycling than with bumper-to-bumper recycling based on current conditions. Received: February 2, 2000 / Accepted: April 21, 2000     

Comparison of the weight-loss degradability of various biodegradable plastics under laboratory composting conditions

Eight kinds of biodegradable plastics were compared for their degradability in controlled laboratory composting conditions. A thin film of each plastic was mixed into the composting material, and weight-loss degradability was calculated from the weight changes of the film during composting. It was found that weight-loss degradability strongly depended on the specific kind of biodegradable plastic; two were very high, four moderate, and the remaining two very slight. The most easily degradable plastic degraded by as much as 81.4% over 8 days of composting. By comparing the weight-loss degradability with ultimate degradability, which is defined as a molar ratio of carbon loss as CO₂ to the carbon contained in the biodegradable plastic, the order of the ease of degradation of the biodegradable plastics differed. Received: February 7, 2000 / Accepted April 14, 2000