Transitions - Sustainable Design: The Science of Sustainability and Green Engineering - page 115

Table 3.2 Effect of the Characteristics of the Contaminant on Decontamination Efficiencies a

Organic Contaminants Inorganic Contaminants

Petroleum Phenolic Other

Treatment Technology PCBs PAHs Pesticides Hydrocarbons Compounds Cyanide Mercury Heavy Metals

Conventional incineration D D D D D D xR pR

Innovative incineration b

D D D D D D xRI

Pyrolysis b D D D D D D xRI

Vitrification b

D D D D D D xRI

Supercritical water oxidation D D D D D D U U

Wut air oxidation pD D U D D D U U

Thermal desorption R R R R U U xR N

Immobilisation pI pI pI pI pI pI U I

Solvent extraction R R R R R pR N N

Soil washing c pR pR pR pR pR pR pR pR

Dechlorination D N pD N N N N N

Oxidation d N/D N/D N/D N/D N/D N/D U XN

Bioremediation e N/pD N/D N/D D D N/D N N

a PCBs, polychlorinated biphenyls; PAHs, polynuclear aromatic hydrocarbons; D, effectively destroys contaminant; R, effectively removes contaminant;
I, effectively immobilizes contaminant; N, no significant effect; N/D, effectiveness varies from no effect to highly efficient, depending on the type of
contaminant within each class; U, effect not known; P, partial; X, may cause release of nontarget contaminant.
b This process is assumed to produce a vitrified slag.
c The effectiveness of soil washing is highly dependent on the particle size of the dediment matrix, contaminant characteristics, and the type of extractive
agents used.
d The effectiveness of oxidation depends strongly on the types of oxidant(s) involved and the target contaminants.
e The effectiveness of bioremediation is controlled by a large number of variables, as discussed in the text.
( Source : U.S. Environmental Protection Agency, Remediation Guidance Document, EPA-905-B94-003, Chapter 7, U.S. EPA, Washington, DC, 2003.)

A word of warning : The policy and scientific inertia of the events of the twentieth
century led to a viewpoint that problems and events can be grouped by media (i.e.,
air, water, and land). Agencies are structured around this view. However, such
thinking is wholly inconsistent with integrative, green solutions. Green design
requires an appreciation for the interactions within and between environmental
media. As mentioned in Chapter 2, if we let the thermodynamics dictate our
thinking, we can begin to approach environmental problems from a multimedia,
multicompartmental perspective, allowing the designer to consider the properties
and behavior of the principal environmental fluids, especially air and water.
Eliminating or reducing pollutant concentrations begins with assessing the
physical and chemical characteristics of each contaminant and matching these
characteristics with the appropriate treatment technology. All of the kinetics
and equilibria, such as chemical degradation rates, solubility, fugacity, sorption,
and bioaccumulation factors, will determine the effectiveness of destruction,
transformation, removal, and immobilization of these contaminants. For example,
Table 3.2 ranks the effectiveness of selected treatment technologies on organic and
inorganic contaminants typically found in contaminated slurries, soils, sludges,