PART 1 INTRODUCTION TO ENVIRONMENTAL ENGINEERING
Unit 1
TEXT: Environmental Engineering
What Is Book About?
The objective of this book is to introduce engineering and science to the interdisciplinary study of environmental problems: their causes, why they are of concern, and how we can control them. The book includes:
l Description of what is meant by environment and by environmental syste*** Information on the basis causes of environmental disturbances
l Basis scientific knowledge necessary to understand the nature of environmental problems and to be able to the quantify them
l Current state of the technology environmental control in its application to water, air and pollution proble*** Considerable gaps in our current scientific knowledge of understanding and con-trolling many of the complex interaction between human activities and nature
l Many environmental problems which could be eliminated or reduced by the application of current technology, but which are not dealt with because of society’s lack of will to do so, or in many instances because of a lack of resources to do so.
Some Important Definition
Where they are first used in this book, definitions are introduced in block form, as shown here, or printed in blod type.
Environment is the physical and biotic habitat which surrounds us; that which we can see, heat, touch, smell, and taste.
System, according to Wehster’s dictionary, is defined as “a set or arrangement of things so related or connected as a unit or organic whole; as, a solar system, irrigation system, supply system, the world or universe”.
Pollution can be defined as an undesirable change in the physical, chemical, or biological characteristics of the air, water, or land that can harmfully affect the health, survival, or activities of humans or other living organisms.
When the goal of improving environmental quality is taken to be improving human wellbeing, the word “environment” broadens to include all kinds of social, economic, and cultural aspects. Such broadness is unworkable in many real situations and impractical in a textbook designed for a one-semester course. Our examination of environmental problems is therefore limited by our definition of “environment”.
Interaction System
A number of different environmental problems are associated with water, air, or land systems. Many of these problems will apply only within one of these systems, justifying the breakdown into these categories. Such a classification is also useful for easier comprehension of related problems within one system. Moreover, it is sensible because, for managerial and administrative reasons, such subfields as air pollution, water supply, wastewater disposal, and solid waste disposal are often dealt with separately by governmental agencies.
Unfortunately, many important environmental problems are not confined to an air, water, or land system, but involve interactions between systems. A current example is the acid rain problem stemming from the emission of sulfur dioxide and nitrogen oxide gases into the atmosphere from the stacks of generating stations, smelters, and automobile exhausts. These gases are then transported by air currents over wide regions, Rainfall “washes them out”, creating acid rain which is harmful to aquatic life, forests, and agricultural crops. Two examples of interaction between systems that cause major environmental disturbance are presented-the buildup of atmospheric carbon dioxide, a global problem, and the acid rain problem, normally of regional nature.