排序方式: 共有65条查询结果,搜索用时 15 毫秒
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李福生 《石油化工环境保护》2001,24(3):51-54
介绍了利用反渗透废水作为循环水补充水的工业实践,运行2年多循环水系统运行稳定,各项指标均达到循环水水质标准,节约了大量水资源。 相似文献
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蒋蔚琪 《石油化工环境保护》1998,(4):17-21
着重阐述了该厂系统划分的情况,系统划分的经济比较,主体单元的设计特点,得出一个利用老厂的给排水公用工程设计必须根据各老厂的具体情况,优化给排水系统划分。 相似文献
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This paper is a contribution to the emergy evaluation of systems involving recycling or reuse of waste. If waste exergy (its residual usefulness) is not negligible, wastes could serve as input to another process or be recycled. In cases of continuous waste recycle or reuse, what then is the role of emergy? Emergy is carried by matter and its value is shown to be the product of specific energy with mass flow rate and its transformity. This transformity (τ) given as the ratio of the total emergy input and the useful available energy in the product (exergy) is commonly calculated over a specific period of time (usually yearly) which makes transformity a time dependent factor. Assuming a process in which a part of the non-renewable input is an output (waste) from a previous system, for the waste to be reused, an emergy investment is needed. The transformity of the reused or recycled material should be calculated based on the pathway of the reused material at a certain time (T) which results in a specific transformity value (τ). In case of a second recycle of the same material that had undergone the previous recycle, the material pathway has a new time (T + T1) which results in a transformity value (τ1). Recycling flows as in the case of feedback is a dynamic process and as such the process introduces its own time period depending on its pathway which has to be considered in emergy evaluations. Through the inspiration of previous emergy studies, authors have tried to develop formulae which could be used in such cases of continuous recycling of material in this paper. The developed approach is then applied to a case study to give the reader a better understanding of the concept. As a result, a ‘factor’ is introduced which could be included on emergy evaluation tables to account for subsequent transformity changes in multiple recycling. This factor can be used to solve the difficulties in evaluating aggregated systems, serve as a correction factor to up-level such models keeping the correct evaluation and also solve problems of memory loss in emergy evaluation. The discussion deals with the questions; is it a pure mathematical paradox in the rules of emergy? Is it consistent with previous work? What were the previous solutions to avoid the cumulative problem in a reuse? What are the consequences? 相似文献
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Trends in waste plastics and recycling 总被引:2,自引:0,他引:2
Tadao Kasakura Reiji Noda Kenichi Hashiudo 《Journal of Material Cycles and Waste Management》1999,1(1):33-37
Zero emission is an ambitious project aimed at the conversion of the conventional top-down or one-directional flow type production
systems of modern society to those of a recycling type. The basic idea underlying this project is to understand in detail
the material flow mechanism in a particular segment of society and to evaluate the transformability of the hitherto one-directional
types of process into recycling types. The authors, members of the Zero-Emission Research Group of Japan, are investigating
the material flow of plastics in Japan. The present work describes the features of this project, as well as the results obtained
so far.
Received: May 28, 1998 / Accepted: October 16, 1998 相似文献
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Recycle technology for waste plastics containing polyvinyl chloride (PVC) has been developed in the Hokkaido National Industrial
Research Institute for the production of solid and liquid fuel, and has established a recycling process which includes a dechlorination
process for PVC plastics, and a two-stage catalytic pyrolysis process for plastics using zeolite catalysts. The dechlorination
equipment consists of a two-axis screw extruder with a heating element, which can remove chlorine up to 99.9 wt. % from PVC
containing plastics as hydrogen chloride. The product had about 44 000 kJ/kg calorific value and was fed into the next oil
production process, although it could also be used as a solid fuel. Natural and synthetic zeolite were used as catalysts for
the two-stage catalytic process, which produced a light oil with a boiling point which was between those of kerosene and gasoline.
The yield of this oil reached 82 wt. %. The chemical type was analyzed using liquid chromatography, and was found to have
many aromatic compounds. These technologies make it possible to produce a nonpolluting, high-calorie solid fuel and a liquid
fuel very efficiently.
Received: July 19, 2000 / Accepted: September 21, 2000 相似文献
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Hirofumi Aizawa Hideto Yoshida Shin-ichi Sakai 《Resources, Conservation and Recycling》2008,52(12):1399-1410
The Japanese system of recycling home electrical appliances has several unique aspects, including (1) a limited number of target appliances, (2) a recycling fee system that requires consumers to pay a recycling fee at the time of disposal, and (3) a direct recycling obligation for manufacturers, who have a physical, rather than a financial, responsibility for their end-of-life products. We studied data from 2001 to 2007 and found that the amount of four specified home electrical appliances and their materials that was recycled increased from about 319,249 tonnes in 2001 to about 447,262 tonnes—or 3.5 kg per inhabitant—in 2006. Recycling yield and development of recycling technologies have also improved. New recycling technologies have enabled a higher rate of material recycling of plastics (i.e., a closed-loop recycling). Improved eco-design, such as design for easier disassembly, has been promoted, and the higher quality of discarded appliances has enhanced the reuse market. Hazardous substances and fluorocarbons are being well managed. Problems with the recycling system include inelastic recycling fees, illegal dumping, illegal transfer by retailers, and the limited number of target appliances. Recycling fees could be reduced; this move might reduce the incidence of illegal dumping, as would engage stakeholders in collaborative efforts against illegal dumping. Illegal transfers could be reduced by improved traceability for retailers. Products such as liquid crystal displays, plasma display panels and clothes dryers have become increasingly common and should be also be targeted for recycling. 相似文献
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