The stainless steel pump and casing might contribute trace amount of:

The stainless steel pump and casing might contribute trace amount of:
Answer
Chromium (Cr)
Iron (Fe)
Nickel (Ni)
All of above
1 points
Question 27
1.
Explain which one of the following has the least potential for cross contamination:
Answer
PVC
Teflon
FRE
Aluminum
1 points
Question 28
1.
Which of the following sampling device/media is based on absorption (not adsorption) and/or chemical reaction:
Answer
Tedlar bag
Canister
Impinger
XRD sorbent
1 points
Question 29
1.
In general and for practical purpose, how much water sample you would collect for metal analysis (assuming the amount would be sufficient at least for dupliacte analysis):
Answer
100 mL
1 L
5 L
10 L
1 points
Question 30
1.
Which one of the following should be monitored in the field if possible:
Answer
acidity
dissolved oxygen (DO)
pesticides
hardness
1 points
Question 31
1.
Which one of the following analyte in water has the maximum holding time (MHTs) of “days” rather than “hours” or “months”?
Answer
Dissolved oxygen
Metals
Pesticides
Salinity
1 points
Question 32
1.
Which of the following sample container material may leach boron (B) and silicon (Si):
Answer
PVC
plastics
stainless steel
glass
1 points
Question 33
1.
Which one of the following generally requires the least volume of sample (in liter) needed for subsequent analysis:
Answer
TPH in liquid wastes
Total metals in water
Trace pesticide in water
Water to perform acute toxicity test
1 points
Question 34
1.
Which of the following is an effective way to preserve water sample containing cyanide (CN-) as a result of potential volatilization loss:
Answer
Add HNO3 to pH < 2
Add H2SO4 to pH 12
Add Na2S2O3
1 points
Question 35
1.
Coliwasa is generally used for collecting:
Answer
solid samples from a pile of solid wastes
liquid samples from a drum of hazardous materials
solid samples from a drum of solid hazardous materials
none of above
1 points
Question 36
1.
For practical purpose, the minimum amount of water sample sufficient for the single analysis of trace organics is approximately:
Answer
10 mL
100 mL
1 L
10 L
1 points
Question 37
1.
Which one of the following is NOT true regarding sample container?
Answer
Plastic container is preferred over glass one for inorganic analytes
Containers should have Teflon-lined caps for extractable organic analytes
If both plastic and glass containers can be used, then glass container is preferred
Certain glass containers may leach significant amount of boron (B) and silicon (Si)
1 points
Question 38
1.
Which one of the following is used in the sampling of hazardous waste in 50-gallon drums:
Answer
Ponar
Coliwasa
Ekman dredge
Kemmerer
1 points
Question 39
1.
Well purging is used primarily to:
Answer
remove stagnant water
clean sampling pump and tubing
minimize cross-contamination
none of above
1 points
Question 40
1.
For which of the following allocation method of stratified random sampling design, its cost is considered through either the optimal precision for a fixed study cost or the optimal cost for a fixed level of precision:
Answer
equal allocation
optimal allocation
proportional allocation
Neyman allocation
1 points
Question 41
1.
A stratified sampling plan was adopted for a contaminated site as a result of a recent oil spill in an open agricultural land. Three strata were chosen: 1) the heavily contaminated surface soil (0-2 ft); 2) the unsaturated soil (2 ft to the groundwater level at 7ft deep); and 3) the saturated zone (7 ft-27 ft). Results for benzene concentrations (mg/kg) are surface soil ( = 25, s = 4.0, n = 15), unsaturated soil ( = 17, s = 2.0, n = 6), and saturated soil ( = 10, s = 1.0, n = 5). If the proportional allocation method is based on the depth or volume ratio, then the weight of surface soil, unsaturated soil, and saturated soil are, respectively:
Answer
A.
0.58, 0.23, 0.19
B.
0.07, 0.19, 0.74
C.
15, 6, 5
D.
2, 5, 20
1 points
Question 42
1.
Which one of the following is likely the most appropriate if you have an adequate budget and you are interesting in knowing the information of a spatial or temporal pattern of contamination
Answer
Simple random sampling
Stratified random sampling
Systematic grid sampling
Search sampling
1 points
Question 43
1.
A stratified sampling plan was adopted for a contaminated site as a result of a recent oil spill in an open agricultural land. Three strata were chosen: 1) the heavily contaminated surface soil (0-2 ft); 2) the unsaturated soil (2 ft to the groundwater level at 7ft deep); and 3) the saturated zone (7 ft-27 ft). Results for benzene concentrations (mg/kg) are surface soil ( = 25, s = 4.0, n = 15), unsaturated soil ( = 17, s = 2.0, n = 6), and saturated soil ( = 10, s = 1.0, n = 5). If the proportional allocation method is based on the depth or volume ratio, then the overall mean concentration is:
Answer
A.
12.4
B.
17.3
C.
20.3
D.
none of above
1 points
Question 44
1.
If you are estimating a population mean and you have budget constraints. The analytical costs are much higher compared to sampling costs. Your goal is to produce an equally precise or a more precise estimate of the mean with fewer analyses and lower cost.
Answer
A.
Simple random sampling
B.
Systematic random sampling
C.
Stratified random sampling
D.
Composite sampling
1 points
Question 45
1.
Which of the following may represent the challenge of collecting the “representative” (e.g., due to heterogeneity) biological samples (e.g., fish) for bioaccumulative contaminant concentrations?
Answer
types of fish species
all of above
various fish tissues
fish size
1 points
Question 46
1.
Preliminary data show a pile of solid waste from a solvent recovery facility has trichloroethene concentration of 7.0 mg/kg (average of 4 samples) and standard deviation of 1.2 mg/kg. The regulatory soil screening level for trichloroethene is 6 mg/kg. The required minimum number of sample for an estimation at the 80% confidence is _____.
Answer
1 points
Question 47
1.
Which of the following statement is generally NOT true:
Answer
Quality of data is primarily determined by the nature of analytical methods (instrumentations).
Analytical data can be reported to the 3rd decimal points , if sampling error are known to dominate.
Errors in the analytical results often are influenced much more by the measurement steps than sampling and sample preparation techniques.
All of above
1 points
Question 48
1.
Which of the following is likely the least preferable sampling approach if the objective is to delineate the extent of contamination:
Answer
Search sampling
Simple random sampling
Judgmental sampling
Systematic sampling
1 points
Question 49
1.
Which one of the following may represent cost saving if the “average” concentration is of the primary concern
Answer
Simple random sampling
Stratified random sampling
Systematic random sampling
Composite sampling
1 points
Question 50
1.
The issue of collecting “representative” solid samples may be the result of:
Answer
concentration variations along with different soil depths
contaminants present in the “nugget” form
contaminants present in two immiscible phases
all of above