1pollutants with relatively ___ henry's law constant can be economically stripped from water
high
2what does air stripping do?
transfer volatile components of a liquid into an air stream
3what type of compounds can be removed reasonably with air strippers?
VOCs, TCE, BTEX
4does henry's law constant increase or decrease with temperature?
increase
5how do you identify stream order?
1. Identify first order streams (perennial streams) - no other streams feed them
2. Stream order increases when streams of the same order intersect (intersection of 2 links of diff orders will not increase)
6list four gas phase technologies
bioventing, incineration, soil vapor extraction, and wet scrubber
7what is bioventing?
in situ treatment technology that simulates microorganisms by adding gas to degrade organic contaminants present in unsaturated soil
8what is the purpose of bioventing?
enhance the biological remediation of haz waste
9what type of compounds is bioventing best for treating?
compounds of low volatility
10what are the two ways bioventing can be implemented?
injection or extraction well
11how does pump and treat work?
pumping liquid from the subsurface extracts liquid from the macropores which is then treated above ground (ex-situ)
12does faculative bacteria need oxygen?
faculative bacteria will use oxygen if available as an electron acceptor but can also use nitrate or organic compounds if oxygen is absent
13how is recharge different between unconfined and confined aquifers?
unconfined aquifers recharge with rainwater quickly, whereas confined aquifers recharge slower and have to use gravity to move water into the aquifer
14what is an aquifer?
an underground body of rock/sediment that stores large amounts of groundwater
15what is a confining unit?
rock or sediment that restricts groundwater flow and is located next to an aquifer
16what is the difference between a losing stream and a gaining stream?
a losing stream has water that is going to groundwater whereas a gaining stream has water coming from groundwater
17what are other names for the zone of aeration?
unsaturated zone or vadose zone
18what is the water table?
boundary between vadose zone and saturated zone
19what is porosity?
portion of volume of a materials that consists of open spaces
20what is permeability?
the speed at which fluid can travel through porous medium
21what contaminants can be targeted with pump and treat?
dissolved contaminants
22what does air sparging (soil vapor extraction) do?
inject air into contaminated groundwater to volatize contaminants for extracting and to stimulate microbial activity (in-situ and ex-situ)
23what contaminants can be targeted with air sparging (soil vapor extraction)?
VOCs, benzenes, toluene, TCEs
24what does in situ thermal soil remediation do
heat is added subsurface and spreads above and below water table which vaporizes contaminants which are then extracted to the surface and treated
25what type of contaminants can in situ thermal soil remediation treat
organic contaminants with low boiling points (gas, chlorinated solvents, PCBs, dioxin, mercury)
26what is phytoremediation
using trees to treat things like metals
27will fine sand have a higher or lower drawdown than coarse gravel
higher
28what is transmissivity
measure of an aquifers ability to transit fliud flow
29what is hydraulic conductivity
measure of a fluids ability to flow through soil
30what is the aquifer thickness often the distance between
the lower confining layer to the upper confining layer or to groundwater table
31what is piezometric head
sum of pressure and elevation head (Pamma + z)