These seem to me to be very poor questions for an exam.  However, I'll take a stab at some of them.


1. What chemical will accelerate Eutrophication in a lake (my answer was Aluminum) I would guess nitrogen.  Was this a multiple choice test?  If so, what are the other choices?

2. If there is infiltration from one sanitary sewer to another what till happen to the Ammonia concentration? (my answer was Rise)  I can't really imagine this happening; but, if it did, I don't know what effect it would have on ammonia.

3 What is the minimum channel velocity in a grit chamber? (this one was in cm/sec  my answer was 120cm/per second) According to me ancient copy of MOP8, for a "non-aerated" grit chamber, a good velocity is 0.3 meter/second = 1 foot/second.

4. If water temperature increase oxygen saturation? (my answer was increases) The saturation concentration of oxygen in water increases as the temperature decreases.  In other words, cold water can contain more oxygen that warm water.

5. Centrifuge pump internal re-circulation is prevented by what part of the pump (my answer was Volute, other possible answers were wear rings, impeller, and shaft) This seems like a crappy question to me.  I would think all those parts prevent internal recirculation.  I guess the volute is as good an answer as any.

6. Increased carbon dioxide will? (my answer was lower pH)

7. What is the volatility in domestic wasterwater Suspended Solids (i chose less than 10%)

8. When starting a Reciprocating  pump how should the valves be lined up?  (i chose suction open, discharge closed) I would think that you would want both inlet and discharge valves open.  Or, am I missing something.

[color=#0000ff][/color][/color]1. What chemical will accelerate Eutrophication in a lake (my answer was Aluminum) I would guess nitrogen.  Was this a multiple choice test?  If so, what are the other choices? I dont remember what the other choices were for this question.  [color=#0000ff]Nitorgen and Phosphorous compunds
2. If there is infiltration from one sanitary sewer to another what till happen to the Ammonia concentration? (my answer was Rise)  I can't really imagine this happening; but, if it did, I don't know what effect it would have on ammonia.  .. Nothing should happen normaly the ammonia conc. in domestic wastewater is the same levels.
3 What is the minimum channel velocity in a grit chamber? (this one was in cm/sec  my answer was 120cm/per second) According to me ancient copy of MOP8, for a "non-aerated" grit chamber, a good velocity is 0.3 meter/second = 1 foot/second. For this questions the available answers were in Cenitmeters/Second. Which was weird because there was nothing on the conversion chart for this measurement.  The velocity range in a non areated grit chanber is 0.2 - 0.4 meters/sec  or 20 - 40 cm/sec .. 1 cm = 0.01 meter
4. If water temperature increase oxygen saturation? (my answer was increases) The saturation concentration of oxygen in water increases as the temperature decreases.  In other words, cold water can contain more oxygen that warm water. Yea I figured i got this one wrong

5. Centrifuge pump internal re-circulation is prevented by what part of the pump (my answer was Volute, other possible answers were wear rings, impeller, and shaft) This seems like a crappy question to me.  I would think all those parts prevent internal recirculation.  I guess the volute is as good an answer as any.  It is the wear rings ..  By the time the volute is an issue due to wear, time to buy a new pump.
6. Increased carbon dioxide will? (my answer was lower pH) .. Correct take a pH reading of a carbonated drink ... Acidic.
7. What is the volatility in domestic wasterwater Suspended Solids (i chose less than 10%) Typicaly it is 70% VS

8. When starting a Reciprocating  pump how should the valves be lined up?  (i chose suction open, discharge closed) I would think that you would want both inlet and discharge valves open.  Or, am I missing something.[/color] I think this was a trick question, i figured all pumps would need both inlet and outlet valves open before start up. Not sure why i chose that answer.  [color=#0000ff]These types of pumps are positive displacement class pumps, and both valves must be open.

If I may add to this; there are several very good study guides available from WEF & AWWA as well as on youtube.  Enter "Wastewater math or studies" and you'll get some very helpful info.

Have you gotten your results yet?  Where are you located?  If the test was done electronically they should have had your results then with the cert to be mailed after a dbl chk of the results.

Dallas