Design and Analysis of Water Quality Control Structures
CAE 440

Summer 2012
CAE 440
SOLUTIONS TO HOMEWORK 3
1. Two methods by which the flow of water can be measured:
1 Venturi Meter See page 349 V&H figure 10.1
2 Parshall Flume See page 350 V&H figure 10.2
2.
Q = 40 mgd = 62.04 ft3/s
Q = VA where V = Vmax = 2.5 ft (Pg. 352 V&H)
Design and Analysis of Water Quality Control Structures
CAE 440

Summer 2012
CAE 440
SOLUTIONS TO HOMEWORK #2
1.
Problem 11.7
The dominant form of alkalinity in natural water at pH 7 is HCO3.
The forms present at pH 10.5 are CO32 (most dominant), HCO3, and OH at
lower concentrations.
2.
Compute concentrations of [H+], [OH], [
Design and Analysis of Water Quality Control Structures
CAE 440

Summer 2012
CAE 440
SOLUTIONS TO HOMEWORK #1
1a.
7.23 x 102 = 10x
x = log 7.23 x 102
x = 1.14
1b.
Use exponents in base 10
[(7.23 x 102) (8.52 x 101)]/ (6.85 x 108)
(101.14 x 100.07)/ (107.16)
10[1.14 + (0.07)(7.16)]
105.95 or 8.91 x 105
2.
Problem 11.1
Design and Analysis of Water Quality Control Structures
CAE 440

Summer 2012
CAE 440
SOLUTIONS TO HOMEWORK #6
Chapter 12
Problem #21
Q = 10,000/3785 = 2.64 mgd
Hydraulic EP = 2,640,000/120 = 22,000 persons
BOD EP = (2.64 x 1300 x 8.34)/0.20 = 143,000 persons
Problem #25
Sources
Total Wastewater
Slaughterhouse
Soup Canning Plant
To