green science and technology

               
                        GREEN SCIENCE AND
TECHNOLOGY
CHAPTER 2. THE FIVE ENVIRONMENTAL SPHERES
The discussion of green science and technology in this book is organized around five major,
interacting environmental spheres: (1) the hydrosphere, (2) the atmosphere, (3) the geosphere, (4)
the biosphere, and (5) the anthrosphere. All of these spheres are introduced in this chapter because
it is important to have a basic understanding of what each entails in order to discuss the remainder
of the material in the book. Later in the book three chapters are devoted to each of the environmental
spheres.
This chapter describes each of the five environmental spheres, the relationships between them,
and the interchanges of matter and energy among these spheres. An important feature of this book
is its treatment of the anthrosphere as one of the established environmental realms.
The constant exchange of matter among the five major environmental spheres is described
by cycles of matter. Among the important cycles of matter is the hydrologic cycle through which
water circulates among all the environmental spheres. Another important cycle is the rock cycle
in which molten rock solidifies, undergoes weathering, may be carried by water and deposited as
sedimentary rock, is converted to metamorphic rock by heat and pressure, and is eventually buried
at great depths and melted to produce molten rock again. Some of the most important cycles are
biogeochemical cycles. These are elemental cycles, such as those of carbon, oxygen, and nitrogen
in which living organisms play a significant role. In the carbon cycle, for example, photosynthetic
organisms remove carbon dioxide from the atmosphere and put the carbon in it into the form of
biological carbon, whereas organisms that degrade organic matter release carbon dioxide back into
the atmosphere.

Green Science and Technology: The Path to a Sustainable Future, Chapter Summaries
CHAPTER 3. GREEN CHEMISTRY, BIOLOGY, AND BIOCHEMISTRY
Chapter 3 includes a basic coverage of chemistry, biology, and biochemistry for readers whose
backgrounds in these subjects may be deficient.
The coverage of chemistry begins with a discussion of the fundamental properties of atoms
and the elements from which they are made. The electronic structures of the first 20 elements are
discussed and they are placed in an abbreviated 20-element periodic table. Chemical bonding,
molecules, and chemical compounds are described making use of electron-dot formulas to
illustrate bonds between atoms. Both ionic and covalently bound compounds are described. Other
fundamental chemical principles covered are the mole, chemical reactions, chemical equations,
catalysts, acids (along with the concept of pH), bases, salts, and solutions.
Also included in Chapter 3 is a brief discussion of organic chemistry. Formulas of organic
molecules are given and the importance of molecular geometry is emphasized. Hydrocarbons
illustrative of organic compounds and molecules are discussed in some detail.
Green chemistry is defined as the practice of chemical science and manufacturing within a
framework of industrial ecology in a manner that is sustainable, safe, and non-polluting and that
consumes minimum amounts of materials and energy while producing little or no waste material
as illustrated in the figure below.
Biology is the science of life and the organisms that comprise life. Living organisms are
defined with respect to the following: (1) Constitution by particular classes of life molecules, (2)
hierarchical organization, (3) capability to carry out metabolic processes, (4) ability to reproduce,
(5) development, and (6) heredity. Biological phenomena are discussed in this chapter as they
apply to green science and sustainability.
Biochemistry is discussed as the chemistry of life processes and life molecules. Emphasis
is placed upon biochemical processes as they apply to sustainability, such as biosynthesis of
commercial chemicals.

CHAPTER 4. WATER: A UNIQUE SUBSTANCE ESSENTIAL FOR LIFE
This chapter begins with a discussion of the water molecule and its unique properties, including
polar character and ability to form hydrogen bonds. These properties give water as a material unique
characteristics essential for life, the environment, and sustainability, such as its special solvent
properties. The occurrence of water on Earth and in various environmental spheres is discussed.
Patterns of water utilization and water as a sometimes very scarce essential resource are discussed
as important aspects of sustainable water utilization. A major concern with the utilization of scarce
water are uneven patterns of precipitation as shown below for the continental United States. In this
figure, the numbers indicate annual precipitation in cm per year, and the figure shows that regions
of the western and southwestern United States that are growing rapidly in population are also areas
of least precipitation
Bodies of water have numerous characteristics that affect the chemistry and biology that
occur in them. Typically, a lake or impoundment has a warmer, less dense, upper epilimnion
layer in contact with the atmosphere in which oxidized chemical species predominate, a lower,
warmer, more dense hypoliminion in which reduced chemical species predominate due to the lack
of oxygen, and sediments, in which important chemical and biological processes occur. To a large
extent, aquatic chemistry is determined by biological processes, which are especially important in
carrying out oxidation/reduction processes. Flowing water in streams and rivers is an important,
often scarce, resource that is threatened by development and over-use in some areas of the world.
Groundwater occurs in underground aquifers and has been seriously depleted by excessive pumping
to provide water for irrigation. Groundwater is susceptible to contamination and an important
aspect of sustainability is prevention of groundwater contamination and preservation of this crucial
resource.
This chapter discusses “water as a very useful green substance.” Water is used — often
wastefully — for irrigation, and increased efficiency of such use is a key aspect of water
sustainability. Enormous quantitities of water are employed for industrial processes, an area in
which much higher efficiencies are possible. Water is an important material in technology, with
some electronic applications requiring “hyperpure” water. Water is not destroyed when it is used
and the ability to recycle water is an important aspect of sustainability.
Green Science and Technology: The Path to a Sustainable Future, Chapter Summaries