Mass Balance Technique
Material Cycles
Water Cycle
Carbon Cycle
Nitrogen Cycle
Sulfur Cycle
Oxygen Cycle
Industrial Use of Materials
Industrial Ecology
Industry as an Ecological System
Industry as an Economic System
Decision Making Techniques of Industrial Ecology
Internet Links
Other Resources
Materials System PDF
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Industrial Ecology

Industry is characterized as an economic activity in which materials are taken in, transformed and disbursed as products and dispensed of as waste. Over the last two centuries, technology has afforded us many ways of transforming materials so we have new, long-lived materials both as products and as waste.

The natural material cycles described in a previous section are part of our ecosystem. Over billions of years, materials, energy and life have all evolved to part of a natural ecology. In recent years, environmental problems and resource depletion have led to the rethinking of industrial uses of materials. The previous section gives some details of material use in industry. Whereas it has been customary to dispose of materials at the end of their use, industry especially in the U.S. and Europe, has begun to move toward a better accounting of material use, to exploring ways of using less energy and materials in production, and how to recycle materials and energy.

The scheme of industrial use of materials which tries to conserve and recycle materials is called Industrial Ecology. Industrial Ecology represents significant changes of mindset - or paradigm shift - from the previous centuries since the Industrial Revolution. Prior to this philosophy, we extracted and disposed of materials from nature as though nature provided us with an inexhaustible supply and as though nature could simply absorb increasingly large quantities of waste materials, some of which could not be degraded by natural processes.

The first move was to remove pollutants from the environment or to reduce pollutant emissions rather than to effect whole systemic changes. Resource depletion, air pollution, and the shortage of land and energy led to the first examination by industry of how to recover material from used items rather than keep extracting new material from earth.

A short review of Industry from the early economic vantage point and from the new ecological vantage point will give more background to the development of Industrial Ecology and decision making techniques that have evolved from the new paradigm of Industrial Ecology. Throughout the next sections, Industrial Ecology may be referred to as I.E.




  ©Copyright 2003 Carnegie Mellon University
This material is based upon work supported by the National Science Foundation under Grant Number 9653194. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.