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15 Cards in this Set

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  • Back
1. which one of these is not a modification of activated sludge process.
a. conventional
b. step feed
c. contact stabilization
d. high rate aeration
a. conventional
2. which of the following are not key factors in activated sludge nitrification?
a. DO
b. TKN loading
c. temperature
d. sunlight
d. sunlight
3. secondary effluent clarity can be measured with a secchi disc?
true or false
true
4. in a conventional activated sludge process, how much oxygen is required per lb of BOD removed?
a. 0.00 to 0.8lb O2/lbBOD
b. 0.8 to 1.2lb O2/lbBOD
c. 1.2 to 2.0lb O2/lbBOD
b. 0.8 to 1.2lb O2/lbBOD
5. To lower the F:M ratio from 0.4 to 0.3 during the next week you should:
a. increase the RAS rate
b. decrease the RAS rate
c. increase the WAS rate
d. decrease the WAS rate
d. decrease the WAS rate
6. An abundance of stalked ciliates in an activated sludge plant is preferred to an abundance of flagellated ciliates.
true or false
true
7. In activated sludge, the Kraus process involves using:
a. anaerobic digested supernatant
b. high rate diffusers
c. RAS chlorination
a. anaerobic digested supernatant
8. An oxygen uptake rate (OUR) determines what type of microorganisms are present.
true or false
false
9. Waste activated sludge wasting rates should not be altered more than___% on a daily basis.
a. 1-5
b.10-20
c. 50-60
d. 30-40
b.10-20
10. Which microorganisms are most responsible for stabilization or organic material?
a. rotifers
b. stalked ciliates
c. bacteria
d. nematodes
c. bacteria
11. A plant that is experiencing white foam on the aeration basins typically has a high MCRT.
true or false?
true
12. Given the following, determine the solids retention time (SRT) in days.
Aeration tank volume = 1MG
Final Clarifier volume = 0.5MG
Influent flow = 4.0 MGD
WAS flow = 75,000gpd
MLSS = 2400 mg/L
Waste sludge TSS = 6200 mg/L
Final Effluent TSS = 12 mg/L
a. 5.2 days
b. 3.1 days
c. 7.2 days
d. 4.5 days
a. 5.2 days
13. CCSS stands for:
a. cubic centimeters of sludge solids
b. compacted clarifier sldge solids
c. clarifier core suspended solids
c. clarifier core suspended solids
14. When doing a 30min activated sludge settleability test, a 100ml Imhoff cone should be used.
True or False
True
15. For a conventional activated sludge plant the F:M ratio should be in the range of:
a. 2.0 - 5.0
b. 0.01 - 0.07
c. 0.2 - 0.5
d. 0.07 - 0.15
c. 0.2 - 0.5