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76 Cards in this Set

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What is pressure head caused by:
Water elevation
What color should the piping be that contains reclaimed water?
purple
What is the term for the height to which a column of water will rise in a well?
piezometric surface
What is the maximum practical lift of pumps?
15 - 25ft
Which one of the following valves is best to use in throttling flow situations?
globe
Which one of the following devices is used to measure water depths in storage facilities?
transducer
the velocity in sanitary sewers is approximately:
2ft/s
The distance between manholes ranges from:
300 - 500ft
What should the flow velocity be through a grit channel?
1.0ft/s
Grit washers are used to:
remove some of the organic matter
The most common flow measuring device for wastewater is a:
Parshall Flume
The detention time for primary clarifiers usually has a range of:
1.5 - 2hrs
The effluent from which process is called mixed liquor?
activated sludge
Aerobic ponds usually range in depth from:
3 to 6ft
Anaerobic ponds usually range in depth from:
8 to 12 ft
Another name for a waste stabilization pond is:
raw wastewater lagoon
What average percent of total solids in domestic wastewater, both dissolved and suspended, are organics?
50%
What average percent of total solids in domestic wastewater, both dissolved and suspended are inorganics?
50%
Approximately what percent of the dissolved solids in wastewater organics?
87%
Which type of oranisms would most probably be associated with moderate sludge age and effluent water quality?
12%
Which type of organisms would most probably be associated with moderate sludge age and effluent water quality?
free swimming ciliates
Which type of organisms would most probably be associated with high suspended solids and biochemical oxygen demand (BOD)?
amoebas
High suspended solids and BOD are most probably assoiciated with which type of oransims?
flagellates
Which type of organism would most likely enhance the penetration of oxygen into the activated sludge?
rotifers
Chlorine gas has a specific gravity of:
2.5 sp gr
Proper flow velocity through a grit channel is indicated when the grit being removed contains:
a little organic material
Surface loading and detention time in a clarifier are directly related to:
flow through the clarifier
What is the expected range for the removal of settleable solids from a primary clarifier?
95 - 99%
What condition will occur if sludge is not pumped out of primary clarifiers at regular intervals?
clarifier will become septic
Secondary clarifiers are usually located after:
a biological process
filter sloughings are a product of:
biological action
When one liquid is dissolved in another liquid it is called:
an emulsion
What is the optimum temp for digester substances?
90F
Which one of the following types of wastewater pounds listed below is not classified like the other three?
aerobic pond
What type of pond would recieve wastewater from a secondary treatment system?
polishing pond
The color of the biofilm on rotating biological contactor undergoing nitrification would appear:
reddish brown to golden
The color of the biofilm on a rotating biological contactor that has high sulfer concentrations would appear:
chalky white
Rotating biological contactors have all the following advantages except:
high sludge production
A wastewater plant has a train of three rotating biological contactor (RBC) units. The color of the first RBC is ___; the color of the second RBC is ___; and the color of the third RBC is ___.
1 gray
2 reddish brown
3 reddish brown
Which one of the following activated sludge process modifications is very sensitive to bulking?
conventional modification
Which modified activated sludge process does not require primary treatment?
contact stabilization
Primary treatment is not required in which modified activated sludge process?
extended aeration activation sludge
Mixed liquor is a combination of the following mixture:
activated sludge in an aeration tank mixed with primary effluent and return sludge or raw wastewater
In a small package wastewater treatment plant, the operator should try to keep the dissolved oxygen in the aeration tank at approximately:
2.0mg/L
How much of the solids should be wasted each week in the summer from a package wastewater treatment plant for the best water quality?
5%
At what concentration level should dissolved oxygen be maintained during the initial startup of an oxidation ditch?
2.0mg/L
What should be the color of an oxidation ditch that is working properly?
medium brown to dark brown
Which one of the following is the least important in the successful operation of an activated sludge plant?
BOD
What is the critical factor in any method to control the aeration tank?
F:M ratio
What is the most accurate measure of the organisms present in an aerator for treating incoming wastes?
MLVSS (mixed liquor volitile suspended solids)
Most algae are in the:
protista kingdom
Bacteria are in the:
monera kingdom
Grease should be cleaned from walkways with a stiff brush and:
trisodium phosphate
Which one of the following types of substance is not soluble in water and has the potential of creating explosive conditions?
flammable oils
Which one of the following types of substances can cause obstructions in the sewer system and may cause anaerobic decomposition where the substances accumulate?
settleable solids
Which one of the following types of substances is corrosive and may interfere with biological treatment?
acids and alkalies
Which one of the following types of substances can be toxic to wastewater plants using biological systems and may adversely affect potable water supplies downstream?
heavy metals
Where would toxicants least likely cause a problem for a wastewater treatment plant?
clarifier
If an activated sludge plant is hit with a high organic load, what will most likely occur in the aeration tank?
there will be a significant decrease in DO
In the following list, which is the least important nutrient in wastewater treatment for microorganisms to reproduce?
potassium
Adequate BOD/nitrogen/phosphorus ratio for microorganisms to grow is usually:
100:5:1
Humus sludge is biomass from:
trickling filters
Excessive slime growths on a trickling filter may cause a conditionon the filter called:
ponding
Another name for slime growth is:
zoological film
It is not recommended to start up trickling filters in the ___ because bacteria are most often dormant at this time.
winter
When the influent load to a wastewater treatment plant changes rapidly, the best test for control purposes is:
COD
A problem with odors from trickling filters may be solved by:
using masking agents
What can be done to the trickling filter to solve high effluent suspended solids?
decrease recirculation
Approximately how much surface area of a rotating biological contactor is immersed in the wastewater?
40%
How many stages are usually present in the rotating biological contactor process?
four stages
Rotating biological contactors are adversely affected by temperatures below:
55%
How often should the oil be changed in the speed reducer of a rotating biological contactor?
every 6 mths
How often should the motor bearings be greased in a rotating biological contactor unit?
every 12 mths
How often should the mainshaft bearings be greased in a rotating biological contactor unit?
every week
How often should the drive bearings be greased in a rotating biological contactor unit?
every week
How often should the oil in the chan casing be changed?
every 3mths