Study Guide Flashcards
1
Q
3 types of alkalinity
A
Hydroxide, bicarbonate, carbonate
2
Q
2 materials found in wastewater to make fertilizer
A
Nitrogen and phosphorus
3
Q
Where do you place the leak on a leaking chlorine container?
A
On top, chlorine is heavier than air
4
Q
Lab records must be kept on file for how long?
A
3 years
5
Q
Solids files must be kept on file for how long?
A
5 years
6
Q
Emergency contact lists should be verified?
A
Quarterly
7
Q
2 pumps of same capacity operate together with a single main, the discharge will be?
A
The same as one pump
8
Q
A common maintenance procedure for UV is?
A
Check and clean the quarts sleeves
9
Q
Most likely cause of fluctuating discharge output in a progressive cavity pump
A
Leak in suction line
10
Q
The beveled edge of a weir is located?
A
At the top face of the weir
11
Q
For security, Scada should not be connected to?
A
The internet
12
Q
What is the purpose of a fecal bath?
A
Regulate temperature
13
Q
Carbon-nitrogen-phosphorus ratio?
A
100:5:1
14
Q
What chemicals reduce or eliminate chlorine residual?
A
Sulfur dioxide and sodium metabisulfite
15
Q
In electrical circuits what is used to reduce voltage when necessary
A
Transformer
16
Q
This gas is found in digester start up
A
Carbon dioxide
17
Q
Amperometric titration is used to measure?
A
Chlorine residual
18
Q
Fecal coliform test is recorded as
A
Geometric mean
19
Q
What happens if you can not obtain a chlorine residual?
A
Nitrates in the effluent
20
Q
To achieve an overall threat rating for a specific event you should look at
A
The magnitude of the impact
21
Q
Threshold limit value time weighted average is what?
A
Max allowable exposure for 8 hours with no harmful effects
22
Q
Electrical pressure available to cause a flow of current when an electrical circuit is closed is what?
A
Voltage
23
Q
Besides viscosity, what is an important consideration in the selection of a lubricating oil?
A
Thermal Range
24
Q
Which of the following explains how to handle a chlorine release?
A
Emergency Response plan
25
Uniforms, if, and stated logos on wastewater system vehicles are critical components of?
Public awareness and security program
26
What’s the easiest way to determine whether the rotor or stator on a progressive cavity pump is worn?
Track the discharge flow rate over time
27
Improper rotation in a centrifugal pump may cause?
Reduced or no flow
28
Wear ring are installed in a pump to?
Wear instead of the impeller
29
What device is used to measure chlorine flow rates?
Rotameter
30
When working in a confined space where flammable gases may be present, use tools only made of what?
A non sparking alloy
31
In addition to the worker entering a confined space, what is the minimum number of people required to be present in a confined space entry?
1
32
During morning checks you notice that the bearings in a pump are running hot. Why is that happening?
The bearing are over lubricated
33
An increase in carbon dioxide content in wastewater will?
Lower the PH
34
Ammonia is added to chlorine to
Maintain the chlorine residual for longer periods of time. (Chloramines)
35
Unit for electrical resistance
Ohm
36
If PH drops in a anaerobic digester, what happens to alkalinity?
Lowers
37
Constant weight is obtained when?
The weight change is less that 4% of the previous weight
38
Materials purchased and received by the utility should be
Verified against the purchase order
39
Wastewater flows with large objects should be pumped by?
A pump with a closed impeller
40
The best back-flow prevention device is?
An air gap
41
To assure a pump is delivering design flows and pressures you should?
Measure flows and pressures and compare to manufacturer pump curve
42
What method if used to determine DO
Winkler Titration
43
What type of materials should be avoided to piping systems involving ferric chloride?
Metals
44
Type of pump used to decrease the overall specific weight of a confined column of gas to water mixture?
Air lift
45
What do you do to adjust your sample before ammonia distillation?
Raise the PH
46
COD sample holding time is
28 days
47
2 gases that are most prominent in digester start up
Carbon dioxide and nitrogen
48
As the temp increases, the oxygen transfer rate?
Increases
49
Orifice has to do with
Air gas flow meter
50
Ammonia sample preservation
Cooling sample to <6*C
Lowering PH to <2 with H2SO4
51
Holding time for PH, DO, and chlorine residual test
15mins
52
Easiest way to determine if progressive cavity internal elements are worn is
Low Discharge pressure
53
2 bacteria in digesters
Acid Formers
Methane/ Gas Formers
54
Facultative ponds are made up of?
An aerobic top layer
An anaerobic bottom layer
55
What gas has the lowest exposure limit?
H2S Hydrogen Sulfide
56
Chlorine leaks may be detected by?
Ammonia solution
57
Vector control is what?
To control the way a disease travels with organisms that carry diseases
58
Probe used with a portable DO meter is?
Polarographic
59
Holding time for nitrate
Cool <6*C
48 hours
60
Holding time for preservation of BOD
Cool<6*C
Sulfuric Acid
48hrs
61
Holding time for Alkalinity
14 days
62
Hold time for Ammonia sample once preserved
28 days
63
Holding time for FOG
28 days
64
What is added to a COD sample to prevent chlorine interference
Mercury Sulfate
65
Difference between COD and BOD
Cod is a fasted test and cod tends to have higher results than BOD
66
How often should the temp change on a anaerobic digester
1* F per day
67
If there is white billowing foam and an increase in hound sludge?
Decrease wasting
68
Mechanical bar screen rake inoperative but motor runs you should?
Check/ replace the shear pin
69
When using an evaporator in disinfection, the chlorine pressure reducing valve should be located where?
Down stream of the evaporator
70
Foaming in aerobic digester, what do you do?
Slow down the feed rate
71
When pumping a corrosive liquid, what should the diff range of the seal water should be compared to the pumps discharge pressure.
5 to 9.9 (34.5 to 68.2 kPa)
72
If an air compressor is cycling on and off frequently, what is the cause?
Leaky valve
73
A pump station with variable frequency drives with 2 complete pumping units provided, what flow should each pumping unit be capable of delivering?
The max daily design flow of the station
74
During normal operation of positive pressure, open-circuit self-contained breathing apparatus what should be closed?
The bypass valve
75
Maintenance required for capacitance level indicators includes?
Checking and cleaning the connections
76
A recently rebuilt centrifugal pump has been returned to service and is now drawing more amps than usual. What is the most likely problem?
Packing is too tight
77
If a centrifugal pump vibrates and is noisy what could be the cause?
Air is in the pump
78
The primary indicator of an upset anaerobic digester is?
Volatile acids increase and Alkalinity decreases
79
Typically, the presence of light, stiff, white foam on the surface of an aeration tank is a indicator of what?
High F:M
Decrease Wasting
80
When collecting nocardia samples where is it highly concentrated?
In the foam
81
In an anaerobic digester, gas pressures are maintained by a controlling mechanism that commonly regulates?
6 to 8 inches of water column pressure
82
When determining the suction head or lift of a centrifugal pump, measure the distance from the?
Water surface to the center line of the impeller
83
The head against which a a pump must operate is
The sum of the static head and the friction head
84
Suction lift on a centrifugal pump should not exceed
25ft
85
Open channel flow devices are primarily
Parshall Flume
86
What does a drain tap do on a digester
Drain condensation from gas piping
87
Most significant problem in using activated sludge process to treat cannery waste
Nutrient imbalance
88
A gravimetric belt feeder uses this to measure
Weight
89
In conducting an oxygen uptake, the feed sample consists of
RAS
90
How is the amount of oxygen transferred by aerators affected by the water temperature
Oxygen transfer rate increases as the temperature increases
91
Aeration tank effluent PH is a 7.4. Effluent PH is a 6.5. MCRT is 14.5 days. What is the most likely cause
Insufficient alkalinity to support the nitrification process
92
The addition of high strength anaerobic digester supernatant to the head of the aeration tank will
Decrease the DO
93
Chain of custody procedures follow a sample for
Sample collection to sample disposal
94
This type of pump can pump 6% solids
Positive displacement pump
95
How is a valve named?
By the shape of its internal closing mechanism
96
NPDES
National pollutant discharge elimination system
97
When is sludge considers properly digested
When 50% of organic matter has been destroyed and converted to gas
98
How long does proper digestion take
Take 30 days @35*C or 95*F
99
How should digester supernatant be handled
Fed slowly back to the head of the plant to avoid shock loading or over loading of nutrients
100
What ratio of methane and carbon dioxide is found in digesters?
70% methane
30% Carbon Dioxide
101
Algae used the process of photosynthesis by
Using carbon dioxide to produce oxygen
102
What may cause a reduction in the pump discharge rate?
Suction lift higher than anticipated
103
Plant influent appears black and has a foul odor each morning. The cause is traced to a pump station at a subdivision which is oversized for the subdivision. What can you do?
Decrease the distance between the on and off pump time in the wet well. (Pumps will run more frequently)
104
Most important factor in preventing accidents at a wastewater plant
Attitude of the employees
105
If other factors remain constant, the capacity of a centrifugal pump increases when the?
Head of the pump increases
106
Upon inspecting an idle centrifugal effluent pump? You notice the shaft is spinning backwards. What should you do?
Check the check valve
107
If equipment fails but there is no danger to the public the repair is classified as what?
Corrective maintenance
108
They type of maintenance used to extend equipment life, reduce maintenance costs, and increase reliability is referred to as?
Preventative
109
Establishing a baseline for the performance of equipment over time is a necessary step in maintenance.
Predictive
110
Filamentous bacteria are identified by
Long strands of bacteria growing like spaghetti or strands of hair
111
What benefits could come from the addition of hydrogen peroxide into collection system?
Oxidation of odor compounds
Keeps system aerobic preventing odors
Kills odor producing bacteria
112
What is the BOD contribution of a person per day?
.17lbs
113
How long does a BOD test take?
5 days
114
How long does a COD test take?
2 to 3 hours
115
Ozone is only generated on-site because?
It is unstable
116
Straggler floc
Young sludge
117
Stalked ciliates are the predominant organisms found in your mixed liquor, this means?
Mixed liquor is healthy and the facility is running well
118
Fecal coliform preservation and hold time
Cool to <10*C
.2ml of 3% solution of sodium thiosulfite
8 hour hold time
119
1.2kw and 120 volts, calculate amps
10 amps
120
If an industry is sending your plant 300mg/l of BOD. You also have a town sending you flow serving 2700 people. What percentage of the load is coming in the industry?
40%
