LE 2 CONCEPTS (M7) Flashcards
a function of soil type, rock type, antecedent water, and time.
rate of infiltration
includes all the material between the Earth’s surface and the zone of saturation
vadose zone
The upper boundary of the zone of saturation
water table
a layer of variable thickness that directly overlies the water table. Water is drawn up into this layer by capillary action.
capillary fringe
a formation that allows water to be accessible at a usable rate.
aquifer
have non-permeable layers, above and below the aquifer zone, referred to as aquitards or aquicludes
Confined aquifers
Sometimes a lens of non-permeable material will be found within more permeable material. Water percolating through the unsaturated zone will be intercepted by this layer and will accumulate on top of the lens.
perched aquifer
has no confining layers that retard vertical water movement
unconfined aquifer
confined under hydraulic pressure, resulting in free-flowing water, either from a spring or from a
Artesian aquifers
Processes that contribute to groundwater recharge
- precipitation
- streamflow
- leakage
- artificial means
any process that removes water from an
aquifer system
Groundwater discharge
the driving force that moves groundwater
Hydraulic head
Rate at which water and air move from upper to lower soil layers
Permeability
groundwater withdrawal exceeds natural recharge rates
Overdraft
emits alpha particles that can damage lung tissue
Radon
Long term exposure can lead to kidney problems
Uranium
- A term used to denote any liquid which is immiscible with water
- Associated with petroleum hydrocarbons such as those leaking
from underground storage tanks or accidental spills from organic
chemicals
Non-aqueous-Phase Liquids (NAPL)
- Specific gravity less than water
- Primarily associated with the production, refining, and distribution of petroleum products
Light NAPL (LNAPL)
- Specific gravity greater than water
- Related to a wide variety of industrial activities, including almost all facilities where degreasing, metal stripping, chemical manufacturing, or other activities involving chlorinated solvents were performed
Dense NAPL (DNAPL)
Dissolved solids are carried along with the flowing fluid
Advection
Mixing of the contaminant resulting from movement through complex pore structures
Dispersion
Occurs when a concentration gradient exists
Diffusion
the incorporation of a substance in one state into another of a different state
Absorption
the physical adherence or bonding of ions and molecules onto the surface of another molecule
Adsorption
as been established as a good adsorbent. Its effectiveness to remove heavy metals such as Zn, Pb, Cu, etc. has already been verified. Used in treatment of domestic and mining wastewater
Coco peat
an oxidation-reduction reaction that is mediated by microorganism
Biodegradation
refers to the cleanup or other methods used to remove or contain a toxic spill or hazardous materials from a contaminated site
Remediation
prevent the pollutants in the soil or groundwater from spreading
Containment
eradicate contaminated soil and/or pollutants
Removal
technique application on contaminated soil and/or pollutants
Treatment
subsurface barriers that impede or stop groundwater flow
Slurry walls
consists of large sheets of iron that are
driven into the ground that have zero permeability
Sheet Piling
based on manipulation of water pressures. They are generated by the pressure differentials arising from the extraction of injection of water using wells or drains
Hydraulic barriers
A very common and widely used method for removing contaminated materials.
Excavation of contaminated soil
the most widely used remediation technique for contaminated groundwater. One or more extraction wells are used to remove contaminated water from the subsurface
Pump-and-treat
a fluid is pumped through a contaminated domain to enhance contaminant removal,bthe fluid used is AIR instead of water.
Soil Vapor Extraction (SVE) (Air Sparging)
Chemical oxidation by pumping chemicals/oxidants such as hydrogen peroxide and potassium permanganate. (usually expensive)
Chemical Remediation
any process that uses microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition.
Bioremediation
supplying air and nutrients to soil to stimulate indigenous bacteria
Bioventing
involves supplying oxygen and nutrients by circulating aqueous solutions to stimulate naturally occurring bacteria to degrade organic contaminants.
In-situ Biodegradation
involves the injection of air under pressure below the water table to increase groundwater oxygen concentrations and enhance the rate of biological degradation of contaminants by naturally occurring bacteria.
Biosparging
involves the addition of microorganisms indigenous or exogenous to the contaminated sites
Bioaugmentation
done through plowing; is a simple technique in which contaminated soil is excavated and spread over a prepared bed and periodically tilled until pollutants are degraded
Landfarming
combine contaminated soil with manure, food waste and agricultural waste
Composting
engineered cells are constructed as aerated composted piles. Hybrid landfarming to make degradation faster
Biopiles
processing of contaminated solid material (soil, sediment, sludge) or water through an engineered containment system
Bioreactors
Vegetation-based remediation shows potential for accumulating, immobilizing, and transforming a low level of persistent contaminants.
Phytoremediation
