TEXAS WASTEWATER A
EXAM TEST BANK WITH A STUDY GUIDE | ALL VERSIONS
OF THE EXAM WITH ALL MODULES COVERED | ACCURATE
AND VERIFIED QUESTIONS AND ANSWERS FOR
GUARANTEED PASS | LATEST UPDATE
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2
feet inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3
feet deep.
a. What is the detention time in hours?
b. What is the surface loading in gal/ft2/day?
c. What is the weir loading in gal/linear ft/day?
Formulas
A primary clarifier has a flow of 3.0 MGD and has a diameter of 100 feet. It is 12 feet deep
and has 24 inches of freeboard. What is the detention time in hours?
Formulas
Anaerobic digester gas should contain?
65-75% methane, 25-35% carbon dioxide and 1-5% nitrogen.
An activated sludge plant has an average daily flow of 3.5 MG. The aeration tank capacity
is 1.2 MG with a MLSS concentration of 3200 mg/L. The clarifier has a capacity of 400,000
gallons with a MLSS concentration of 6,000 mg/L. The wasting rate is 40,000 gallons per
day with a MLSS concentration of 8, 000 mg/L. The effluent TSS is 18 mg/L. Assuming
volatile concentrations of 70%, what is the MCRT and what type of activated sludge plant
should this be?
Formulas MCRT
What are some of the causes of filaments in the aeration basin?
a. low DO
b. low organic loading
c. septic wastes
d. nutrient deficiencies .
e. high sulfur content
Good sludge quality will have a predominance of what organisms in the MLSS?
,Ciliated protozoa
When an RBC is operating correctly, how will the slime appear on the media?
Grey to brown 0.05 to 0.1 inches thick
According to design criteria, what are the minimum allowable diameters for a manhole?
24 inch opening and 48 inch inside diameter
What activated sludge process does not achieve complete nitrification?
Contact Stabilization
In the selection of forced main wastewater piping, what is the minimum working pressure?
150 psi
The oxygen depletion of BOD dilution water should not exceed
0.2 mg/L.
What is the minimum air gap when making water and wastewater connections?
Minimum of one inch or twice the inlet pipe size whichever is greater.
What is the minimum useful size pipe to prime a centrifugal pump?
1 inch
An anaerobic digester must maintain an average year round temperature of
95 degrees F.
How do you remove shoring from a trench?
From the bottom up
Which of the following methods would you use to increase the degree of nitrification in an
activated sludge plant?
increase dissolved oxygen levels and increase the sludge age
Which of the following are considered normal operator controls on an activated sludge
plant?
aeration rates return and wasting rates
Reducing the return sludge flow rate for an activated sludge system which has a good
settling sludge will ________.
increase the RAS concentration and the clarifier sludge blanket thickness
, An extended air activated sludge plant has a fast settling sludge and high amounts of pin
floc leaving the clarifier. One way to correct this problem is to ________.
* reduce the MCRT by wasting more
* increase the F/M ratio by wasting more
The primary causes of wastewater stoppages are ________.
roots and grease
The inside diameter of a manhole must be how wide?
48 inches
On a construction job site, equipment booms must maintain at least how many feet of
clearance from overhead electric lines?
10 feet
Digester gas should contain about ________.
a. 65% - 75% methane
A treatment plant has two primary clarifiers. Each has a diameter of 40 feet and a depth of
12 feet. If the design flow is 1.2 mgd, find the surface loading on each clarifier in
gallons/ft2/day. Assume the flow is equally split between the two clarifiers.
3.14 x 20 x 20 = 1256
1,200,000 /2
= 600,000 gallons each
600,000/ 1256
b. 478 gallons/ft2/day
Distilled water used for the BOD analysis should not exceed ________.
0.2 mg/L depletion
One element of being an effective communicator is to ________.
a. be a good listener
In order to promote a collaborative management style, one thing a supervisor can do is
________.
join the team as a member rather than as boss
One thing an employee can do to be a good team member is to ________.
try to understand other people's needs and desires
EXAM TEST BANK WITH A STUDY GUIDE | ALL VERSIONS
OF THE EXAM WITH ALL MODULES COVERED | ACCURATE
AND VERIFIED QUESTIONS AND ANSWERS FOR
GUARANTEED PASS | LATEST UPDATE
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2
feet inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3
feet deep.
a. What is the detention time in hours?
b. What is the surface loading in gal/ft2/day?
c. What is the weir loading in gal/linear ft/day?
Formulas
A primary clarifier has a flow of 3.0 MGD and has a diameter of 100 feet. It is 12 feet deep
and has 24 inches of freeboard. What is the detention time in hours?
Formulas
Anaerobic digester gas should contain?
65-75% methane, 25-35% carbon dioxide and 1-5% nitrogen.
An activated sludge plant has an average daily flow of 3.5 MG. The aeration tank capacity
is 1.2 MG with a MLSS concentration of 3200 mg/L. The clarifier has a capacity of 400,000
gallons with a MLSS concentration of 6,000 mg/L. The wasting rate is 40,000 gallons per
day with a MLSS concentration of 8, 000 mg/L. The effluent TSS is 18 mg/L. Assuming
volatile concentrations of 70%, what is the MCRT and what type of activated sludge plant
should this be?
Formulas MCRT
What are some of the causes of filaments in the aeration basin?
a. low DO
b. low organic loading
c. septic wastes
d. nutrient deficiencies .
e. high sulfur content
Good sludge quality will have a predominance of what organisms in the MLSS?
,Ciliated protozoa
When an RBC is operating correctly, how will the slime appear on the media?
Grey to brown 0.05 to 0.1 inches thick
According to design criteria, what are the minimum allowable diameters for a manhole?
24 inch opening and 48 inch inside diameter
What activated sludge process does not achieve complete nitrification?
Contact Stabilization
In the selection of forced main wastewater piping, what is the minimum working pressure?
150 psi
The oxygen depletion of BOD dilution water should not exceed
0.2 mg/L.
What is the minimum air gap when making water and wastewater connections?
Minimum of one inch or twice the inlet pipe size whichever is greater.
What is the minimum useful size pipe to prime a centrifugal pump?
1 inch
An anaerobic digester must maintain an average year round temperature of
95 degrees F.
How do you remove shoring from a trench?
From the bottom up
Which of the following methods would you use to increase the degree of nitrification in an
activated sludge plant?
increase dissolved oxygen levels and increase the sludge age
Which of the following are considered normal operator controls on an activated sludge
plant?
aeration rates return and wasting rates
Reducing the return sludge flow rate for an activated sludge system which has a good
settling sludge will ________.
increase the RAS concentration and the clarifier sludge blanket thickness
, An extended air activated sludge plant has a fast settling sludge and high amounts of pin
floc leaving the clarifier. One way to correct this problem is to ________.
* reduce the MCRT by wasting more
* increase the F/M ratio by wasting more
The primary causes of wastewater stoppages are ________.
roots and grease
The inside diameter of a manhole must be how wide?
48 inches
On a construction job site, equipment booms must maintain at least how many feet of
clearance from overhead electric lines?
10 feet
Digester gas should contain about ________.
a. 65% - 75% methane
A treatment plant has two primary clarifiers. Each has a diameter of 40 feet and a depth of
12 feet. If the design flow is 1.2 mgd, find the surface loading on each clarifier in
gallons/ft2/day. Assume the flow is equally split between the two clarifiers.
3.14 x 20 x 20 = 1256
1,200,000 /2
= 600,000 gallons each
600,000/ 1256
b. 478 gallons/ft2/day
Distilled water used for the BOD analysis should not exceed ________.
0.2 mg/L depletion
One element of being an effective communicator is to ________.
a. be a good listener
In order to promote a collaborative management style, one thing a supervisor can do is
________.
join the team as a member rather than as boss
One thing an employee can do to be a good team member is to ________.
try to understand other people's needs and desires
