Wastewater Midterm Review Flashcards
1
Q
- What should be done to a sample that has settled solids on the bottom of the sample jar prior to testing in laboratory? V2.7E-P499-500 (16.33)
A
Thoroughly mix the sample
2
Q
- What problem can be expected when high nitrogen content is present in plant effluent that is being discharged to a stream? V1-7E-P23 (2.5)
A
Abundance of algae growth
3
Q
- Why should soda-acid fire extinguisher never be used on an electrical fire? V2-7E-P303 (14.41)
A
Harmful gases will be produced
4
Q
- What do algae use to support metabolic functions? V1-7E-P294 (9.0)
A
Nitrogen & phosphorus
5
Q
- When analyzing data, a proportional increase or decrease in the values is called: V2-7E-P128 (11.1061)
A
Trend
6
Q
- Which manual is approved for use in determining proper lab procedures? V2-7E-P471 (16.00)
A
Standard methods
7
Q
- If a pump will not start, what should an operator check first? V2-7E-P367 (15.18)
A
Tripped circuit breaker
8
Q
- What can happen when a centrifugal pump is operated against a closed discharge valve for extended periods of time? V2-7E-P346 (15.115)
A
Cavitation will occur damaging the impeller
9
Q
- Plant effluent samples reveal a high coliform count. The chlorinator is operating properly and there is good residual. What is the most probable cause? V1-7E-P372 (Tab 10.1 9)
A
Short circuiting in contact chamber
10
Q
- Where MLSS samples should be taken in an aerator? V2-7E-P112 (11.1011 = Fig 11.40)
A
Near the effluent and 1 foot below surface
11
Q
- Why are aerobic digesters are sometimes covered? V2-7E-P218 (12.61)
A
To conserve heat in colder temperatures
12
Q
- What process is used to remove chlorine from plant effluent prior to
discharge into receiving waters? V1-7E-P401 (10.90)
A
Dechlorination
13
Q
- What is one reason for aerating wastewater? V1-7E-P65 (4.1)
A
Separate oil & grease
14
Q
- A healthy anaerobic digester will produce: V2-7E-P187 (12.26)
A
CO2 & methane
15
Q
- There is an increase of coliform bacteria in the plant effluent. What is
one possible cause of this? V1-7E-P372 (Tab 10.1 9)
A
Solids build-up in chlorine contact chamber
16
Q
- What is the best indicator of a possible problem in an anaerobic digester? V2-7E-P191 (12.3-B)
A
VA/ALK ratio
17
Q
- When using two lift station pumps, what is the best way to operate
them?
A
Alternated pumps every 24 hours
18
Q
- A properly operating primary clarifier will remove what percentage of suspended solids? V1-7E-P43 (3.5)
A
60%
19
Q
- Which dangerous gas may be found at a wastewater treatment plant?
V2-7E-P268 (Tab 14.1)
A
H2S, CL2, CH4
20
Q
- Why should water never be put on a chlorine leak? V1-7E-P388 (10.52)
A
It will cause pipes and fittings to corrode
21
Q
- What is a good ratio of nutrient levels in domestic wastewater? (BOD:
Ammonia Nitrogen: Orthophosphate)
A
100; 5; 1
22
Q
- What do pieces of stringing rags hanging from a Comminutor
indicate? V1-7E-P80 (4.33)
A
A worn out cutter
23
Q
- What is the maximum amount of chlorine that can be removed from a
150 pound chlorine container in a 24 hour period? V1-7E-P396 (10.64)
A
40 Ibs.
24
Q
- At how many parts per million is chlorine immediately deadly?
V1-7E-P376 (Tab 10.2)
A
1000 ppm
25
Q
- A good settling sludge would consist of what type of protozoa?
V2-7E-P123 (Fig 11.49)
A
Free swimmers and Stalk ciliates
26
Q
- You suspect your anaerobic digester is going sour. What is the best way to verify its condition? V2-7E-P191 (12.3-B)
A
VA/ALK ratio
27
Q
- What is considered normal operation of an aerobic digester?
V2-7E-P218 (12.62)
A
Settle and Decant as Needed
28
Q
- Low DO and nutrient deficiency will promote the growth of what?
V2-7E-P72 (11.62-4)
A
Filamentous bacteria
29
Q
- If you pump green sludge to a drying bed what chemical should be
applied? V2-7E-P221 (17.70)
A
Lime
30
Q
- What takes place in the stabilization tank in a contact stabilization plant? V2-7E-P112 (11.1011-3)
A
Absorption
31
Q
- Staffing is based on what? Chapter 62.699
A
Flow and type of Treatment
32
Q
- Why would you chlorinate the RAS line? V2-7E-P74 (11.66)
A
Control filamentous bacteria
33
Q
- What is the most common type of pond? V1-7E-P299 (9.2)
A
Facultative
34
Q
- The ash content in lab procedure is the same as?
A
Inorganic solids
35
Q
- Denitrification will cause what? V2-7E-P73 (11.65)
A
Rising sludge
36
Q
- Coliform count fail to meet standards, your chlorine supply is not the
problem. What most likely is? V1-7E-P372 (Tab 10.1 9)
A
Short circuiting and low contact time
37
Q
- How does temperature effect disinfection?.V1-7E-P352 (10.13)
A
Higher the temp the better the disinfection
38
Q
- How long should you wait after you make a process change before
making another change? V2-7E-P71 (
A
1 week
39
Q
- What is needed to calculate the F/M ratio? V2-7E-P16 (FN 3)
A
CBOD and MLVSS
40
Q
- What types of ponds are used after a trickling filter, activated sludge,
or BC plant? V1-7E-P297 (9.2)
A
Polishing pond
41
Q
- Chlorine is not coming out of the chlorinator, chlorine tank is half full.
What is the most likely problem? V2-7E-P372 (Tab 10.1 9)
A
Manifold line is clogged
42
Q
- If you have a sudden increase of BOD by 50% or a BOD >400. What
is this termed? V1-7E-P43 (3.5 + FN 12)
A
Increased organic load
43
Q
- Coliform bacteria are used for what? V2-7E-P551 (6.A)
A
Indicators of possible presence pathogenic organisms
44
Q
- CL2 combined with ammonia forms what? V1-7E-P350 (10.111)
A
Chloramines
45
Q
- It can be said that: V1-7E-P352 (10.13)
A
The lower the pH, the greater the disinfection
46
Q
- What is a quick test to check sludge condition? V2-7E-P517 (16.450 + FN 12)
A
Settlometer
47
Q
- What is the range of parameters to promote the best microorganism
growth for the Activated Sludge process?
A
2 ppm D.O., pH 7.0,75-95° F
48
Q
- What is the benefit of step feed aeration? V2-7E-P88 (11.83)
A
Treat higher flows in less space
49
Q
- What can happen if more than 40 lbs. of Cl2 is removed from a 150 Ibs. tank in a 24 hr. period? V1-7E-P396 (10.64)
A
Freezing of the lines
50
Q
- In an anaerobic digester, when the VA/ALK ratio starts to increase, what will be noticeable? V2-7E-P191 (12.3 B)
A
An increase in CO2 & decrease in pH
51
Q
- According to FAC Ch. 62-600, Domestic Wastewater Facilities, your job as an operator during major process breakdown is to?
A
Maintain competent documentation and record keeping
52
Q
- Short circuiting in a primary clarifier can be prevented by?
V1-7E-P135 (5.61)
A
Baffles
53
Q
- What do you do if you experience a plant upset due to a hydraulic overload?V2-7E-P70 (11.61 Condition 2)
A
Decrease WAS to maintain microorganism population
54
Q
- You have dark foam, high MLSS, slow settling sludge with a clear
effluent, you should?
A
Maintain 1-3 ft. sludge blanket, monitor MLSS, increase D.O. in necessary
55
Q
- If the blades on the Comminutor become dull, this can cause?
V1-7E-P41 (3.30 FN 7)
A
Pumps to become clogged with rags
56
Q
- After a fall replacement of the roof of the chlorinator storage building the Cl2 stopped feeding during a hot summer day, what is the likely cause?
A
The tank become hotter than the manifold
57
Q
- If an activated sludge plant becomes upset, what is the most important and least time consuming operation an operator should do to discover the cause? V2-7E-P22 (11.041)
A
Check the plant data for the previous 3 weeks
58
Q
- If there is suspected leak with sulfur dioxide. What should you NOT use to detect it and why? V1-7E-P403 (10.921)
A
Soapy water/ Sulfuric acid
59
Q
- What take place in preliminary treatment? V1-7E-P34 (3.2)
A
Removes debris, sand, grit, freshens wastewater
60
Q
- What is the pH range of domestic wastewater producing the best
organic activity? V2-7E-P579 (8 A,B)
A
6-8
61
Q
- What is the proper gas mixture in an anaerobic digester under normal
operation? V2-7E-P191 (12.3 C)
A
70% Methane / 30% Carbon Dioxide
62
Q
- What is the liquid to gas expansion ratio of Chlorine? Florida Level *C° Workbook Chapter 8 P73
A
460: 1
63
Q
- A predominance of Nematodes, Rotifers, and Pin Floc in the effluent
indicates? V2-7E-P123 (Fig 11.49)
A
Old Sludge
64
Q
- What are the three groups of Protozoa commonly found in good activated sludge? V2-7E-P119 (11.1031-3)
A
Ciliates, Flagellates, & Amoeba
65
Q
- Which is an indication of Old sludge? V2-7E-P123 (Fig 11.49)
A
Low SVI & Low F/M ratio
66
Q
- How long does It take until the results of a COD test are avallable?
V2-7E-P541 (16.51-3)
A
4 hours
67
Q
- What are Saprophytic organisms? V2-7E-P148 (12.00 + FN 3)
A
Organisms that thrive on dead or decaying organic matter
68
Q
- What does a predominance of free swimming ciliates in the mixed
liquor indicate? V2-7E-P119 (11.1031-3)
A
A stable operation
69
Q
- Septic conditions in the collection system will cause the pH to.
V1-7E-P1 0-?
A
Decrease
70
Q
- Under what conditions will Filamentous organisms thrive?
V2-7E-P119 (11.1031-3)
A
When D.O. is low
71
Q
- What is it called when the velocity is greater in some sections of a
clarifier than in others? V1-7E-P135 (5.61 2)
A
Short circuiting
72
Q
- What is the most desirable pH in a pond? V1-7E-P301 (9.3)
A
7.5
73
Q
- What nutrients are used by green algae? V1-7E-P294 (9.0)
A
Nitrogen and Phosphorous
74
Q
- When operating a pond, what tests should be performed on a regular
basis (1-2 times per week)? V1-7E-P309 (9.610 D)
A
D.O., pH, and Temperature
75
Q
- Excessive D.O. levels can cause?. V2,7E-P19 (11.02)
A
Pinpoint floc
76
Q
- Sludge pumped from a clarifier sump should be? V1-7E-P130 (5.3)
A
As thick as possible
77
Q
- What is indicated by a high SVI and slow settling? V2-7E-P60-1 (11.560-1)
A
Young sludge
78
Q
- What happens to the pH in a pond during the day when algae are
consuming carbon dioxide, producing oxygen? V1-7E-P299 (9.3)
A
Increases
79
Q
- The removal of settleable organic solids is an example of? V1-7E-P43 (3.5)
A
Primary Treatment
80
Q
- Which of the following is a cause of white foam? V2-7E-P49 (11.41) & P53 (11.501)
A
Activated Sludge Solids level too low
81
Q
- Which of the following may be the cause of Filamentous type bulking?
A
Septic influent wastewater
Low D.O. levels in the aeration tank
Oils & Grease
82
Q
- Which is a description of good solids in an aeration tank? V1-7E-P266 (8.26)
A
Golden to dark brown and granular
83
Q
- White fluffy foam indicates? V2-7E-P75 (11.67 4)
A
Low MLSS in aerator
High F/M ratio
84
Q
- Which organisms will predominate when the F/M ratio is low?
V2-7E-P123 (Fig 11.49)
A
Rotifers
85
Q
- Which of the following is the most common short filament? V2-7E-P117 (11.1031-2b)
A
Nocardia
86
Q
- What is the proper ratio of nutrients in domestic wastewater? (BOD:
Nitrogen; Phosphorous; Iron)
A
100; 5/1/0.5
87
Q
- In which class are electrical fires? V2-7E-P303 (14.41)
A
C
88
Q
- What could be the cause of Nocardia and foaming? V2-7E-P127 (11.1052)
A
Industrial waste/toxic shock loading
89
Q
- Which organisms are indicators of the possible presence of
pathogens in water? V2-7E-P551 (6 A)
A
Coliform
90
Q
- Which modification of the activated sludge process requires the use of
two separate aeration tanks? V2-7E-P86-7 (11.81-2)
A
Contact Stabilization
Krause
91
Q
- Which requires an Anoxic Zone for Denitrification? V2-7E-P90 (11.86)
A
Bardenpho
92
Q
- Which would be the best process to use when treating wastes from
canneries and dairies? V2-7E-P87 (11.82)
A
Krause
93
Q
- Which process would better handle a shock load? V2-7E-P88 (11.83)
A
Step-Feed
94
Q
- Which process requires that all parts of the aeration tank be similar in
terms of amount of food, organisms, and D.O.? V2-7E-P90 (11.84)
A
Complete Mix
95
Q
- Which process would best handle fluctuating flows? V2-7E-P93 (11.90)
A
Sequencing Batch Reactor
96
Q
- Where micro samples should be taken in a conventional activated sludge plant? V2-7E-P112 (11.1011)
A
At the effluent end of the aerator
97
Q
- What adjustment would need to be made if the F/M ratio is high?
V2-7E-P19 (11.02)
A
Increase D.O.
98
Q
- Which of the following could be a cause of bulking? V2-7E-P71 (11.62)
A
High F/M Ratio
99
Q
- What color is the foam that is produced when Nocardia are present?
V2-7E-P73 (11.66)
A
Brown
100
Q
- When using Step-Feed aeration, why would you introduce peak flows
from storms or strong industrial wastes into the last half of the tank
rather than the first half? V2-7E-P88 (11.83)
A
To avoid washout of activated sludge solids and culture microorganisms
101
Q
- What is formed when chlorine combines with water?
V1-7E-P349 (10.10)
A
Hypochlorous Acid + Hydrochloric acid
102
Q
- What would a high SVI indicate? V2-7E-P60-4 (11.56-7)
A
High Organic Loading
Predominance of flagellates
High F/M ratio
103
Q
- Which of the following microorganisms are most likely to be found during a difficult plant start up or a toxic overload? V2-7E-P119 (11.1031-3)
A
Amoeba
104
Q
- What adjustment can be made to the primary clarifier to correct a rising sludge problem? V2-7E-P73 (11.65)
A
Remove a primary clarifier from service
105
Q
- How long records must be kept on site? Chapter 62.620
A
Three Years
106
Q
- The Initial Chlorine Demand during disinfection is caused by?
V1-7E-P350 (10.110)
A
Inorganic Material in the water
107
Q
- Which has the best disinfecting power when Hypochlorous acid and
Ammonia are combined? V1-7E-P350 (10.111)
A
Dichloramine
108
Q
- What is the maximum holding time for BOD .samples? V2-7E-P502 (Tab 16.4)
A
48 hours
109
Q
- As the VA/ALK ratio increases, the .
- also increases? V2-7E-P191 (12.3 B)
A
Carbon Dioxide production
110
Q
- How can a Sulfur Dioxide leak be detected? V1-7E-P403 (10.921)
A
A rag soaked in strong ammonia
111
Q
- Why should a sludge line never be closed on both sides?
V2-7E-P221 (12.70)
A
Pressure from gases could cause a line rupture
112
Q
- What is one cause of light colored foam in an aerator? V1-7E-P266 (8.252)
A
Low suspended solids
113
Q
- When changing the temperature of a digester, you should never change it by more than_____degrees F per day?
V2-7E-P191 (12.3 A)
A
1
114
Q
- What is the maximum holding time for pH samples? V2-7E-P502 (Tab 16.4)
A
No holding time
115
Q
- What is a Class B fire? V2-7E-P303 (14.41)
A
Oil
116
Q
- Which of the following organisms are predominate in old sludge? V2-7E-P120 (11.1031-4)
A
Rotifers
117
Q
- Why should a positive displacement pump never be operated against a closed discharge valve? V2 7E-P371 (15.191)
A
Pressure will cause the pipe, pump or valve to rupture
118
Q
- What is the typical pH range of domestic wastewater entering a
treatment plant? V1 7E-P350 (10.111)
A
6.5-7.5
119
Q
- The removal of heavy inorganic solids is an example of? V1-7E-P41 (3.3)
A
Primary Treatment
120
Q
- Nocardia and foaming indicates? V2-7E-P117 (11.1031-2)
A
Low D.O. & Low F/M ratio
121
Q
- What is one cause of light-colored floating sludge solids on the secondary clarifier? V1-7E-P265 (8.252)
A
High aeration rates, decrease rate
122
Q
- At what temperature does a fusible plug in a chlorine cylinder melt?
V1-7E-P378 (10.500)
A
158°F to 165°F
123
Q
- According to D.E.P rules, when is discharge monitoring reports to be
filed by? Chapter 62.600
A
28th of the following month
124
Q
- How often should a primary clarifier be shut down for cleaning?
A
Every 12 months
125
Q
- Why is wastewater disinfected? V1-7E-P347(10.1)
A
To destroy pathogenic bacteria to safe levels
126
Q
- When pumping sludge to a digester it is best to pump? V2-7E-P185 (12.22)
A
Small amounts at frequent intervals
127
Q
- What type of sewer collects domestic waters from homes? V1-7E-P33 (3.10)
A
Sanitary
128
Q
- What conditions could occur when a sludge pump draws sludge too quickly? V2-7E-P185 (12.22)
A
Coning
129
Q
- What methods can be use to dispose of screenings? V1-7E-P71 (4.24)
A
Incineration and burial
130
Q
- A settlometer reveals that after 5 to 10 minutes solids won’t concentrate above 700 to 900, and settling is slow. What does this indicate?
A
Young sludge
131
Q
- How often should manholes be placed in the collection system for
access and maintenance? V1-7E-P34 (3.10)
A
300-500ft
132
Q
- When effluent enters the secondary clarifier with a SVI of 300 what is
likely to occur?
A
The sludge will settle evenly
133
Q
- Wasting rate changes should not exceed what % from one day to the
next? V2-7E-P55 (11.53)
A
10% - 15%
134
Q
- If your floating digester cover is leaning to one side due to a compact
scum blanket, what should you do to correct this problem? V2-7E-P211 (12.44-32)
A
Spray scum blanket with water to soften it
135
Q
- What type of pond is used for waste that has not received any prior treatment? V1-7E-P297 (9.2)
A
Stabilization pond
136
Q
- Why would we treat the RAS line with chlorine? V2-7E-P72 (11.62-4)
A
To control filamentous bacteria
137
Q
- What is a representative portion of a sample called? V2-7E-P813 (definitions)
A
An aliquot
