Contaminant Fate and Transport Flashcards
1
Q
3 phases of transport
A
- Air
- Soil
- Water
2
Q
Rate from fastest to slowest
A
Fastest:
- air diffusion
- water diffusion
- soil diffusion
3
Q
Mechanism controlling the transport of dissolved contaminants in aquifers (3)
A
- Advection
- Mechanical dispersion
- Diffusion
4
Q
Advection definition
A
- Transfer of matter in a fluid, especially horizontally in the atmosphere or the sea
- Useful equation: darcy’s law
5
Q
Mechanical Dispersion definition
A
- Spreading of a solute as it moves through porous media
- Directly related to groundwater velocity
- Mixing is due to tortuosity
6
Q
Diffusion definition
A
-Random molecular movement due to concentration gradient
7
Q
Diffusion: molecular weight vs. diffusivity
A
High MW = Low diffusivity
8
Q
Tortuosity vs. dispersion vs. material sorting
A
Poorly sorted = high tortuosity, more dispersion
Well sorted = low tortuosity, less dispersion
9
Q
Plume (Mechanical Dispersion)
A
Distribution and extent of contaminants migrating in the subsurface
10
Q
DNAPL
A
- Dense nonaqueous phase liquids
- Higher density than water
11
Q
Dispersion
A
The spreading of a solute as it travels through porous media
12
Q
LNAPL
A
- Light nonaqueous phase liquid
- lower density than water
- ex: petrol, will float on top of water table
13
Q
NAPL
A
- non-acqueous phase liquid
- low solubility compounds - will not dissolve easily in water
