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1. What may be the cause of septic odors?

   1.   ?    Aeration D.O. too high
   2.   ?    Low H₂S values in the influent
   3.   ?    WAS rate too high
   4.   ?    Aeration D.O. too low

2. What color foam and scum is typically the result of old sludge?

   1.   ?    White
   2.   ?    Dark brown or black
   3.   ?    Light brown
   4.   ?    Green

3. What is the typical adjustment that is necessary when the influent CBOD₅ increases?

   1.   ?    Decreased WAS rate
   2.   ?    Decreased RAS rate
   3.   ?    Increased WAS rate
   4.   ?    Reduced sludge yield

4. What may be the most probable cause for slow settling MLSS?

   1.   ?    High RAS rate
   2.   ?    Filamentous bacterial growth
   3.   ?    Balanced F/M ratio
   4.   ?    Low sludge blanket

5. What typically happens to the process SRT when the WAS rate is increased?

   1.   ?    SRT decreases
   2.   ?    F/M ratio decreases
   3.   ?    SRT increases
   4.   ?    SRT remains the same

6. What may be the best adjustment to make if pin floc in the clarifier is increasing TSS in the effluent to unacceptable levels?

   1.   ?    Increase the SRT
   2.   ?    Decrease the F/M ratio
   3.   ?    Decrease the SRT
   4.   ?    Decrease the WAS rate

7. What may cause CBOD₅ in the effluent to be unacceptable high?

   1.   ?    Aeration rate too high
   2.   ?    SRT too high
   3.   ?    F/M ratio too low
   4.   ?    Aeration rate too low

8. What may be the most common cause of filamentous bulking in a secondary clarifier?

   1.   ?    Aeration D.O. too low
   2.   ?    SRT too low
   3.   ?    RAS rate too high
   4.   ?    Aeration D.O. too high

9. Which condition is typically not the cause of high effluent ammonia?

   1.   ?    Low influent alkalinity
   2.   ?    High influent ammonia
   3.   ?    Low Aeration rate
   4.   ?    High Aeration D.O.

10. Which condition may cause biologically-bound phosphorus to be released in the secondary clarifier?

    1.   ?    High RAS rate
    2.   ?    Low SRT
    3.   ?    Low RAS rate
    4.   ?    High F/M ratio