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25 Cards in this Set
- Front
- Back
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Secondary carifier has clumping, rising sludge on surface. What is the cause?
a. low temp and low DO in AT b. SRT short c. MCRT short d. dinitrification |
d. dinitrification
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The clarifier is cloudy, pin floc overflowing weir, and lokids rising. What is the likely cause?
a. F/M high b. MCRT short c. F/M low / SRT high d RAS high/ WAS low |
c. F/M low / SRT high
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The aeration tank DO decreases suddenly. There is no problems with the blower. What is the likely cause?
a. increased organic load b. dinitrification c.low RAS d. short AGE |
a. increased organic load
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The AT foam is dark brown, amost black and sudsy, the mixes liquor color is almost black with an odor detected at the aeration tank. What is the cause?
a. MLSS low b. high DO c. anaerobic/ septic condition in AT d. High F/M What needs to be check to verify probem? a. Check MLSS b lower air rates c. reduce F/M d. Chck diffuser, air rate and RAS flow |
c. anaerobic/ septic condition in AT
d. Chck diffuser, air rate and RAS flow |
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Which activated sludge system produces the smallest amt of sudge?
a. anaeroic digersters b. endogenous growth c. extended aeration |
c. extended aeration
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There is an excessive build up of light brown foam on the aeration tank surface. Staggeler floc is obvserved in the clarifier effluent. What condition would you expect to see?
a. Decreased F/M b. Bulking sludge c. high F/M |
c. high F/M
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What conditions are likely causing excessive white foam in aeration tank?
a. low F/M & low solids b. high F/M & high MSS c. high F/M & low MLSS d. low SVI & low MCRT What parameter should you check to verify cause? |
c. high F/M & low MLSS
check the MLSS |
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Which of the following conditions indicate an overleaded AT?
a. brown foam b. stiff white foam c. greasy dark foam d. black foam |
b. stiff white foam
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Which of the following contions are indicative of Nocardia?
a. greasy dark tan foam b. black foam c.brown foam d. none of the above |
a. greasy dark tan foam
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The production of a jellylike, water logged (hydrated) sludge that has a very low density (bound water) is associated with what condition?
a. rising sludge b. short circuiting c. MCRT too high d. bulking |
d. bulking
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Very shiny, dark brown foam in aeration tank. Sprays are on but they can't break up the foam. What is the likely cause?
a. Nocardia b. low BOD c. F/M too high d. MCRT too high What needs to be check to verify cause? |
d. MCRT too high
check MCRT and increase the WAS |
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There is excessive greasy, dark tan foam in the aeration tank & there are finaments in the mixed liquor. What's the problem?
a. Nocardia b. high DO c. low MLSS d. high grease & oil content in influent |
a. Nocardia
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the aeration tank has no sign of air bubbles in some spots of the AT. What is the most likely cause?
a. plugged diffusers b. organic overload c. toxic loading d. hydraulic overload |
a. plugged diffusers
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There is heavy turbulence in some areas of the AT. What is the cause?
a. organic overload b. toxic loading c. broken diffuser d. low RAS rate |
c. broken diffuser
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The secondary clarifier effluent has pin floc & is turbid. the SVI is good. What is the most likely cause?
a. low DO b. low MCRT c. high WAS d. over oxidized sludge |
d. over oxidized sludge
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Clouds of billowing sludge rising and extending thoughout the clarifier. Mixed liquor settles slowly. There are few filamentous organisms. SVI has increased. What is the likely cause?
a. high F/M b. low F/M c. low waste d. B and C |
a. high F/M
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Clouds of billowing homogenous sludge rising and extending thoughout the clarifier. Mixed liquor settles slowly and compacts poorly. Supernatant is fairly clear. There are numerous filamentous organisms extentding beyond the folc into the free water. What is the likely cause.
a. underleaded aeration tank b. high MCRT c. nutrient dificiency d. high MLSS |
c. nutrient dificiency
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Clouds of billowing homogenous sludge rising and extending thoughout the clarifier. Mixed liquor settles slowly and compacts poorly. Supernatant is fairly clear. Microscopic exam show some filamentous organisms. SVI has increased suddenly. What is the likely cause?
a. high F/M b. low F/M c. toxic waste d. low WAS |
c. toxic waste
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Clumps of sludge are rising in clarifier. Bubbles noticed on the clarifier srface. Mixed liquor settles fairly well, but a portion or ll of the sludge rises to the surface within 4 hours after the ssv test is started. What does this indicate?
a. low DO in AT b. short clarifier detention time c. denitrification d. a & b |
c. denitrification
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Secondary clarifier effuent is cloudy and ther is suspended matter. Mixed liquor settles poorly. What is the likely cause?
a. low MLSS b. low MCRT c. stable growth d. increase in organic loading |
d. increase in organic loading
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There is well dispersed pin floc throughout the claridier with sluge accumulation on the surface and carring over the weirs with effluent. What is the likely cause?
a. overloading b.underloading c.low MLSS d. high MLSS |
b.underloading
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Small particles of ash-like material floating on the clarifier surfce. What is the likely cause?
a. toxic waste b. low AT DO c. Denitrification d. short clarifier detention time |
c. Denitrification
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Small particles of ash-like material floating on the clarifier surfce. What is the likely cause?
a. Toxic waste b. excessive grease in mixed liquor c. low MLSS d. high WAS |
b. excessive grease in mixed liquor
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There is straggler floc extending thoughout the secondary clarifier and going over the effluent weirs,Mixed liquor settles fairly well, but dos not compact well. What is the likely cause?
a. high MLSS b. overleaded AT c. high MCRT d. low SVI |
b. overleaded AT
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Effluent analysis indicates high ammonia and nitrite lvls. What is the likely cause?
a. low aeration rate b. high temp c. long AT detention time d. high aeration rate What needs to be checked to verify cause? a. AT temp b. AT aeration rate c. influent Alkalinity & pH d. all the above |
a. low aeration rate
d. all the above |
