Problem 6.29
A final settling tank for a 2milliongallonperday (2 MGD) activatedsludge treatment plant has
an average overflow rate of 800 gal/dayft2. The tank needs to have a minimum detention t
Problem 6.32
A wastewater treatment uses an activated sludge process for secondary treatment of 0.300 m3/s
of primary effluent. The mixed liquor has a concentration of 2,100 mg VSS/L, and the RAS
conc
Problem 6.5
You are trying to remove 10.0 m diameter particles in a water treatment plant. The water is at
20C, and the particle density is 1.2 g/mL. The plant treats 0.100 m3/s of water. It is propos
Problem 2.23
A solution is initially supersaturated with Ca2+ and CO22 ions by rapid addition of calcium
carbonate, such that the concentrations of each are 2.10 103 M. The waters pH is held at 8.5.
Problem 6.20
A sample of water has the following concentration of ions (and the pH is near neutral):
Cations Concentration (mg/L)
Ca2+
95.0
Mg2+
26.0
+
Na
15.0
(a)
(b)
(c)
(d)
(e)
(f)
Anions Concentra
Reading for test 2:
Equilibrium: 2.4
Microbiology/Ecology:handout
Water Resources:
5.2, 5.95.11
Water Pollutants: 5.1, 5.35.6,
Air Pollutants: 7.1, 7.2, 7.5, pgs 444461
Biofuels Paper
There are two broad types of systems for removing BOD from wastewater: lagoons, which are
low cost to build and operate, but take up a lot of space, and activated sludge systems, which
consume energy
Let us consider the case of two particles of same density but different sizes in solution, starting at
the same depth. Will the larger or smaller particle sink to the bottom first, or will they reach
Let us consider the BOD reduction in a wellmixed pond, as shown in Example 6.9 (page 322),
and determine if one pond of 200 m3, two ponds of 100 m3 each in series, or two ponds of 100 m3
each in para
Problem 7.34
A coalfired power plant with effective stack height of 100 m emits 1.2 g/s of SO2 per megawatt
of power delivered. If winds are assumed to be 4 m/s at that height and just over 3 m/s at
Problem 7.32
A point source Gaussian plume model for a power plant uses 50 m as the effective stack height.
The night is overcast. (Note: This is not the same as cloudy in this model; check the footno
Problem 7.29 & 7.30
Suppose the following atmospheric altitude versus temperature data have been collected:
Altitude (m) Temperature (C)
0
20
100
18
200
16
300
15
400
16
500
17
600
18
(a) What would b
Problem 6.18
A water is analyzed and found to have the composition shown in the following table.
Component Concentration
CO2
6.0 mg/L
Ca2+
50.0mg/L
Mg2+
20.0 mg/L
+
Na
5.0 mg/L
Alkalinity
3.1 mmol/L
S
Problem 7.4
A new coalfired power plant has been built using a sulfur emission control system that is 70
percent efficient. If all of the sulfur oxidizes to SO2 and if the emissions of SO2 are limite
Problem 5.53
An oftenused chemical representation of algae is C106H263O110N16P
(a) Determine the mass (mg) of each element in 1 g of algae
(b) Suppose there are 0.10 mg of N and 0.04 mg of P availabl
Problem 5.30
A city of 200,000 people deposits 37 cubic feet per second (cfs) of sewage having a BOD of 28.0
mg/L and 1.8 mg/L of DO into a river that has a flow rate of 250 cfs and a flow speed of 1.
Problem 5.44
Based on observations of the rate of travel between two observation wells of a tracer element
having retardation factor equal to 1.0, it is determined that the average linear flow velocit
Problem 5.43
A 750m section of river runs parallel to a channel 1,000 m away (see Figure P5.43, pg. 274). An
aquifer connecting the two has hydraulic conductivity equal to 7.0 m/d and an average thic
Problem 5.4
A BOD test is to be run on a sample of wastewater that has a fiveday BOD of 230 mg/L. If the
initial DO of a mix of distilled and wastewater is 8.0 mg/L, and the test requires a decrease
TABLE 8.1
Composition of Clean Dry Air (Fraction by Volurrie
in Troposphere, 2006)  .
Constituent Formula Percent by Volume Partsper Million
Nitrogen N; 78.08 780,800
Oxygen 01 20.95 209,500
A
1.
Thereis a 600MW powerplantthat is 38% efficient. It burnscoal that emits9000
efficientsulfur scrubber.
Btu/lb and containsl%osulfur. If the olanthasa70o/o
(lb/hr)?
What is the emission
rateof sulf
Notes from Dr. Capel on water pollutants
I.
Oxygendemanding wastes
A.
Overview
B.
BOD/CODDefinition
C.
BOD/CODHow is it measured?
I.
Oxygendemanding wastes
A.
Overview
Dissolved oxygen is called DO.
Ftt>. "E. . ,.,.~
s'L<f't.(>
"
~;_e .,
(
. f;
(1

H.
6
'.
~.k<
cD
(
BM'terill are the lTlOSI important group of microorganisms. They are esr.emial Itl
I~
nulrienl cycle of lhe ecosymm. Palhogcn
Concept Questions:
1. During the coagulation step, you accidentally dose twice the usual amount of alum. How
will this affect your particle removal?
Overabundance of positive charge can hinder coagul