Biomedical Engineering Reference
In-Depth Information
to the present and future needs of mankind. “This role of chemistry is not generally
recognized by government or the public. In fact, chemicals, chemistry, and chemists are
actually seen by many as the cause of the problems” (Clark, 1999). Indeed, the chemical
industry releases more hazardous wastes to the environment than any other industry
sector and more in total than that is released by the next nine sectors combined (Anastas
and Warner, 1998). It is true that in the production of fine chemicals and pharmaceu-
ticals many individual steps are usually required, and a majority of these are stoichio-
metric, thereby consuming large amounts of reagents. Most of these materials consume
excessive energy in their manufacture. They also entail the use of aggressive, corrosive,
and sometimes explosive reagents, and much waste is generated, which currently is
disposed of in landfills. The need to devise new methods of manufacture that minimize
consumption of energy and materials (including volatile solvents) and that also mini-
mize the liberation of harmful gases (typified by the notorious greenhouse gas, N
2
O) is
pressing. An emerging approach to this grand challenge seeks to embed the diverse set
of environmental perspectives and interests in the everyday practice of the people most
responsible for using and creating new materials—chemists. The approach, which has
come to be known as green chemistry, intends to eliminate the intrinsic hazard itself,
rather than focusing on reducing risk by minimizing exposure.
Hydrophobic pollutants present in petroleum hydrocarbons and soil and water
environment require solubilization before being degraded by microbial cells.
Mineralization is governed by desorption of hydrocarbons from soil. Surfactants
can increase the surface area of hydrophobic materials, such as pesticides in soil and
water environment, thereby increasing their water solubility. Hence, the presence of
surfactants may increase microbial degradation of pollutants. Use of biosurfactants
(BSs) for degradation of pesticides in soil and water environment has gained impor-
tance only recently. BSs are attracting much interest due to their potential advan-
tages over their synthetic counterparts in many fields spanning environmental, food,
biomedical, and other industrial applications.
GREEN CHEMISTRY: AN INNOVATIVE TECHNOLOGY
The term green chemistry was first used in 1991 by Paul T. Anastas in a special
program launched by the U.S. Environmental Protection Agency (USEPA) to imple-
ment sustainable development in chemistry and chemical technology by industry,
academia, and government.
D
efinition
of
G
reen
C
hemistry
The term green chemistry, as adopted by the Working Party, is defined as “The inven-
tion, design and application of chemical products and processes to reduce or to elimi-
nate the use and generation of hazardous substances” (Anastas and Warner, 1998).
Green chemistry is the use of chemistry for pollution prevention. More specifically,
it is the design of chemical products and processes that are environmentally benign.
Advances in green chemistry address both obvious hazards and those associated
with such global issues as climate change, energy production, availability of a safe
and adequate water supply, food production, and the presence of toxic substances
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