CE 403 Optional FE Review:
Environmental engineering
Chris Rehmann
Environmental engineering
A.
B.
C.
D.
E.
Water quality (ground and surface)
Basic tests (e.g., water, wastewater, air)
Environmental regulations
Water supply and treatment
Wastewater collection and treatment
Water quality: Example 1
The world population was about 4 billion in 1975 and 6
billion in 1999. If the growth is exponential, then in
2020 the population in billions will be most nearly
A.
B.
C.
D.
8
10
11
15
Water quality: Example 2
A contaminant is injected uniformly into a tank of
volume 5 L. The contaminant follows a first-order
reaction with decay rate 0.21 d-1. The time in days until
the concentration is half the initial concentration is
A.
B.
C.
D.
1.4
2.4
3.3
4.8
Water quality: Example 3
Micro-organisms are growing according to Monod
kinetics. The maximum growth rate is 0.4 d-1. The
substrate concentration is 25 mg/L, and the saturation
constant is 50 mg/L. The ratio of the growth rate and
maximum growth rate is most nearly
A.
B.
C.
D.
13%
33%
50%
100%
Water quality: Example 4
A tributary with a discharge of 3 m3/s and nitrate
concentration of 20 mg/L meets a river with a
discharge of 30 m3/s and nitrate concentration of 4
mg/L . The concentration in mg/L downstream of the
confluence is most nearly
A.
B.
C.
D.
5.5
12.0
18.2
24.0
Water quality: Example 5
Wastewater is discharged into a river with a mean velocity of
0.25 m/s. After initial mixing the dissolved oxygen concentration
is 7.5 mg/L and the ultimate BOD is 40 mg/L. The reaeration
coefficient is 0.4 d-1, and the deoxygenation coefficient is 0.2 d-1.
The saturated DO concentration is 8.2 mg/L. The dissolved
oxygen concentration (in mg/L) 5000 m downstream is most
nearly
A.
B.
C.
D.
5.8
6.7
8.2
18.6
Adapted from example 8.1 of
Tchobanoglous & Schroeder (1987)
Water quality: Example 6
A river flows through a lake with a volume of 6x106 m3.
The inflow and outflow are both 5 m3/s. The inflow has
a contaminant with a concentration of 10 mg/L and a
decay rate of 0.2 d-1. The steady state concentration of
the outflow in mg/L is most nearly
A.
B.
C.
D.
0.7
2.7
8.3
10.0
Water quality: Example 7
A landfill has a clay liner with a thickness of 80 cm, a
hydraulic conductivity of 10-7 cm/s, and a porosity of
30%. If the hydraulic head is 100 cm, then the time (in
years) for leachate to break through the liner is most
nearly
A.
B.
C.
D.
3.4
5.3
25.4
57.1
Water quality: Example 8
Benzene is leaking from an underground storage tank.
The aquifer has an average linear velocity of 0.03 m/d,
a bulk density of 2 g/cm3, and a porosity of 23%. If the
distribution coefficient is 0.3 mL/g, the speed (in m/d)
at which the flow advects the contaminant is most
nearly
A.
B.
C.
D.
8.3x10-3
1.2x10-2
3.0x10-2
1.1x10-1
Basic tests: Example 9
Hexose is oxidized by the following reaction. What is
the coefficient of hexose?
?? C6H12O6 + 6 O2  ?? CO2 + ?? H2O
A.
B.
C.
D.
1/6
1
6
12
Basic tests: Example 10
A solution has a molar concentration of
hydrogen ions of 1.58x10-4 M. The pH is most
nearly
A. 0.2
B. 1.58
C. 3.8
D.4.0
Basic tests: T&S ex. 2.1a
A 1-L solution contains 20 g of calcium carbonate
(CaCO3). If the density of the calcium carbonate is
1.12 g/mL, then the molarity of the solution is most
nearly
A. 0.0002 M
B. 0.0004 M
C. 0.2M
D. 0.4M
Basic tests: T&S ex. 2.1b
A 1-L solution contains 20 g of calcium carbonate
(CaCO3). If the density of the calcium carbonate is
1.12 g/mL, then the mole fraction of the solution is
most nearly
A. 3.26x10-3
B. 3.65x10-3
C. 4.06x10-3
D. 2.00x10-1
Basic tests: Helmenstine ex. 1
Hydrogen gas (H2) and iodine gas (I2) react to form
hydrogen iodide gas (HI). If the equilibrium constant at
25°C is 7.1x102 and the equilibrium concentrations of H2
and I2 are 0.81 M and 0.035 M, respectively, then the
equilibrium concentration of HI is most nearly
A. 0.05
B. 0.22
C. 4.49
D. 20.1
Basic tests: Example 11
The biochemical oxygen demand of a water sample was
measured to be 140 mg/L at 5 d, and the ultimate BOD
is 160 mg/L. The decay coefficient (in d-1) is most nearly
A.
B.
C.
D.
0.13
0.18
0.20
0.42
Basic tests: Example 12
A wastewater sample has ultimate BOD of 30 g/m3
and a rate coefficient of 0.22 d-1 at 20°C. If the
temperature coefficient q is 1.056, then the ratio of
the 5-d BOD at 25°C and the 5-d BOD at 20°C is
most nearly
A. 0.76
B. 0.87
C. 1.15
D. 1.31
Env. regulations: Example 13
Which of the following deals with permits for
discharges to surface waters?
A.
B.
C.
D.
Clean Water Act
Safe Drinking Water Act
National Environmental Policy Act
Comprehensive Environmental Response,
Compensation, and Liability Act
Env. regulations: Example 14
Which of the following sets maximum contaminant
levels for public drinking water supplies?
A.
B.
C.
D.
Clean Water Act
Safe Drinking Water Act
National Environmental Policy Act
Comprehensive Environmental Response,
Compensation, and Liability Act
Env. regulations: Example 15
Which of the following regulates the criteria pollutants:
carbon monoxide, ozone, NOx, SOx, particulate matter,
and lead?
A.
B.
C.
D.
Clean Water Act
Safe Drinking Water Act
Clear Air Act
National Environmental Policy Act
Env. regulations: Example 16
Which of the following gave the Environmental
Protection Agency the authority to regulate hazardous
waste from “cradle to grave”?
A. National Environmental Policy Act
B. Comprehensive Environmental Response,
Compensation, and Liability Act
C. Affordable Care Act
D. Resource Conservation and Recovery Act
Env. regulations: Example 17
Which of the following is intended to clean the worst
contaminated sites in the U.S.?
A. National Environmental Policy Act
B. Comprehensive Environmental Response,
Compensation, and Liability Act
C. Clean Water Act
D. Resource Conservation and Recovery Act
Water treatment: T&S ex. 12.4
The settling velocity in m/s of a sand particle (density =
2600 kg/m3) with diameter 0.5 mm in water at 20°C is
most nearly
A.
B.
C.
D.
0.089
0.110
0.162
0.218
Water treatment: from T&S ex. 7.4
A batch adsorption test was conducted with 2 L samples of water
with an organic contaminant at a concentration of 20 g/L. When
0.9 and 4 g of activated carbon is introduced, 14 and 28 g of
contaminant is removed, respectively. If the adsorption follows a
Freundlich isotherm, the mass in g of activated carbon needed to
remove 34 g of contaminant is most nearly
A.
B.
C.
D.
5.3
6.2
9.9
12.6
Water treatment: Example 17
A granular medium filter has a 30-cm layer of uniform anthracite
(porosity 35%, diameter 1.6 mm) over a 30-cm layer of uniform
sand (porosity 40%, diameter 0.5 mm). The filtration rate is
0.002 m/s. The ratio of the head loss (computed by the CarmenKozeny equation) in the anthracite and the head loss in the sand
is most nearly
A.
B.
C.
D.
0.30
0.31
0.49
1.00
WW treatment: Longhurst 1
Grit is mainly
A. Inorganic material
B. Organic material
C. Total suspended solids
D. Volatile solids
See http://www.cram.com/flashcards/wastewater-test-quiz-331471
WW treatment: Longhurst 3
The main purpose of primary treatment is to remove
A. Chlorine
B. TSS and CBOD5
C. Ammonia
D. Inorganic material
See http://www.cram.com/flashcards/wastewater-test-quiz-331471
WW treatment: T&S 11.1
For primary sedimentation a circular tank is to be designed with
a hydraulic detention time of 2.5 h and a surface overflow rate of
40 m3/m2·d for a town of 20,000 and wastewater flow of 0.45
m3/capita·d. The depth (in m) of the tank should be most nearly
A. 1.5
B. 2.4
C. 3.3
D. 4.2
WW treatment: Example XX
A wastewater treatment process treats 50,000 gal/d of
sludge containing 2% solids. Thickening and dewatering
reduces the volume of the sludge so that it has 25%
solids. The reduction in volume in gal/d is most nearly
A. 4,000
B. 37,500
C. 46,000
D. 49,000
Adapted from OnlineTechTraining.com