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15 Cards in this Set
- Front
- Back
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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
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2. which of the following are not key factors in activated sludge nitrification?
a. DO b. TKN loading c. temperature d. sunlight |
d. sunlight
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3. secondary effluent clarity can be measured with a secchi disc?
true or false |
true
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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
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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
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6. An abundance of stalked ciliates in an activated sludge plant is preferred to an abundance of flagellated ciliates.
true or false |
true
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7. In activated sludge, the Kraus process involves using:
a. anaerobic digested supernatant b. high rate diffusers c. RAS chlorination |
a. anaerobic digested supernatant
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8. An oxygen uptake rate (OUR) determines what type of microorganisms are present.
true or false |
false
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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
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10. Which microorganisms are most responsible for stabilization or organic material?
a. rotifers b. stalked ciliates c. bacteria d. nematodes |
c. bacteria
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11. A plant that is experiencing white foam on the aeration basins typically has a high MCRT.
true or false? |
true
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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
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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
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14. When doing a 30min activated sludge settleability test, a 100ml Imhoff cone should be used.
True or False |
True
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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
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