Biomedical Engineering Reference
In-Depth Information
CHAPTER 1
BIOAUGMENTATION FOR GROUNDWATER
REMEDIATION: AN OVERVIEW
Delina Y. Lyon and Timothy M. Vogel
Universit
´
de Lyon, Ecole Centrale de Lyon, 69134 Ecully Cedex, France
1.1 INTRODUCTION
1.1.1 Background: The Pollution Problem
As industry has increased over the ages, so has human impact on the environment,
especially with the advent of the Industrial Revolution. This period has been marked by the
introduction of xenobiotic compounds. These were originally defined by Leisinger (
1983
)as
“guest” chemicals that are not natural to the environment, or anthropogenic (“man-made”)
compounds whose structure is relatively new and foreign to microbes that are otherwise very
capable of degrading organic waste (Leisinger,
1983
; Timmis et al.,
1994
). However, recent
work suggests many if not most of these xenobiotics also have natural origins as well (Gribble,
1998
; Keppler et al.,
2002
). Nevertheless, many anthropogenic compounds can present a
difficult challenge for the environment, as natural systems are not adapted for rapid degrada-
tion of these compounds, which often have unusual chemical bonds or halogen substitutions.
For the majority of the past 200 years, treatment and disposal of industrial waste was not a
priority, as exemplified by the dumping of waste into the ground or rivers with the idea that
“dilution is the solution to pollution.” Only in the latter half of the twentieth century was
concern over the fate of the environment brought to the forefront. Even so, it was not until the
publishing of Rachel Carson's
Silent Spring
in 1962 and public outcry over incidents such as
Love Canal in 1978 (Beck,
1979
) that environmental pollution was concretely linked with human
health, leading in part to the establishment of the Environmental Protection Agency in the
United States (USEPA) in 1970 and the ensuing environmental protection acts, such as the
Superfund Program established in 1980 (http://www.epa.gov/aboutepa/history/topics/index.
html; accessed June 18, 2012). As of 2012, there are around 1,300 Superfund sites in the United
States that contain various inorganic and organic contaminants (http://www.epa.gov/superfund/
sites/npl/index.htm; accessed June 18, 2012), and there are still hundreds of thousands of
contaminated sites requiring cleanup (USEPA,
2004
).
The problem of environmental pollution spans the globe and insidiously affects human and
environmental health. Many countries that have adopted modern industrial processes have
discovered the legacy of polluted environments. Nations that are rapidly increasing in either
population or chemical use, such as India and China, realize that their natural resources cannot
support the burden of uncontrolled chemical disposal. While pollution prevention and sustain-
able development measures are preferred, in many cases, the damage has already been done.
Remediation offers the chance to reduce pollutant levels. There are numerous proposed
remediation technologies, incorporating chemical, physical and biological processes.
Despite the availability of so many options, a good remediation strategy that is effective,
efficient and economical can be elusive. To this end, there are a number of tools available online
