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GEOL 205 final exam

Terms in this set (120)

air sparging
-involves the injection of air or oxygen through a contaminated aquifer to remove volatile and semivolatile organic contaminants by volatilization
-injected air helps to flush the contaminants into the unsaturated zone for treatment

bio reactor landfills
-rapidly transform, degrade and stabilize organic waste through the addition of liquid and air, enhancing microbial processes

-uses microorganisms to degrade organic contaminants in soil, GW, sludge and solids
-microorganisms break down contaminants by using them as an energy source or cometabolizing them with an energy source

-applies low intensity direct current through the soil between ceramic electrodes that are divided into a cathode array and an anode array
-current mobilizes charged species, causing ions and water to move toward the electrodes, and removal of contaminants at the electrode may be accomplished by several methods

evapotranspiration covers
-utilize natural processes to manage water precipitating on municipal landfills, hazardous and industrial waste landfills to contain waste

environmental fracturing
-technologies enhance or create openings in bedrock or soil with low effective porosity to help soil and GW cleanup methods to work better

GW circulating wells
-create a 3D GW circulation pattern that can provide subsurface remediation inside a well, in the aquifer, or both
-GW is drawn into a well through one screened section and is pumped through the well to a second screened section where it is reintroduced to the aquifer

in site chemical reduction
-places a reductant or reductant generating material in the subsurface to degrade toxic organic compounds to potentially nontoxic or less toxic compounds
-immobolizes metals by absorption or precipitation and degrades non metallic oxyanions

in situ flushing
-floods a zone of contamination with an appropriate
solution to remove the contaminant from the soil. --Contaminants are
mobilized by solubilization, formation of emulsions or a chemical
reaction with the flushing solutions and brought to the surface for
disposal, recirculation or on-site treatment and reinjection.

in situ oxidation
-typically involves reduction/oxidation (redox)
reactions that chemically convert hazardous compounds to
nonhazardous or less toxic compounds that are more stable, less
mobile or inert.

Multi-Phase Extraction
-uses a vacuum system, sometimes combined
with a downhole pump, to remove various combinations of
contaminated groundwater, separate-phase petroleum product and
vapors from the subsurface. -The system lowers the water table
around the well, exposing more of the formation for vapor extraction

Nanoscale Materials for Environmental Site Remediation
-have been
developed and used to remediate contaminated soil and
groundwater, such as sites contaminated by chlorinated solvents or
oil spills.
-Nanoscale materials can be highly reactive in part because
of the large surface area to volume ratio and the presence of a
larger number of reactive sites

Natural Attenuation
-relies on natural processes to clean up or
attenuate pollution in soil and groundwater. Natural attenuation
occurs at most polluted sites.
-However, the right conditions must
exist underground to clean sites properly

Remediation Optimization
-uses defined approaches to improve the
effectiveness and efficiency of an environmental remedy
-Optimization approaches include site-wide optimization reviews,
statistical evaluation tools, consideration of emerging technologies,
review of operating system costs and the identification of cost
reduction methods without loss of protectiveness

Permeable Reactive Barriers
-s are subsurface emplacements of
reactive materials through which a dissolved contaminant
plume must move as it flows, typically under natural gradient.
Treated water exits the other side of the permeable reactive

-are broadly defined as the use of
vegetation to address contaminants in soil, sediment, surface
water and groundwater.
-Cleanup objectives for
phytotechnologies can be contaminant removal and
destruction, control and containment or both.

Soil Washing
-separates contaminants sorbed onto fine soil
particles from bulk soil in a water-based system based on
particle size.
-Soils and wash water are mixed in a tank or other
treatment unit and usually separated using gravity settling

Soil Vapor Extraction
- applies a vacuum to unsaturated zone
soil to induce the controlled flow of air and remove volatile
and some semivolatile organic contaminants from the soil.

-encapsulates waste to form a solid material,
coat the waste with low-permeability materials to restrict contaminant migration or both.
-Solidification can be
accomplished by mechanical processes or by a chemical
reaction between a waste and binding reagents, such as cement, kiln dust, or lime/fly ash.

Solvent Extraction
-uses an organic solvent to separate organic
and metal contaminants from soil.
-The solvent is mixed with
contaminated soil in an extraction unit and then passed through a separator, where the contaminants and extractant
are separated from the soil.

Ex Situ Thermal Treatment
- generally involves the destruction or removal of contaminants through exposure to high
temperature in treatment cells, combustion chambers or
other means.
-Contaminated media is contained during the remediation process.

In Situ Thermal Treatment
- includes many different methods
and combinations of techniques to apply heat to polluted soil,
groundwater or both. The heat can destroy or volatilizeorganic chemicals, and the gases can be extracted through
collection wells for capture and cleanup in a treatment unit.