Wastewater Midterm Review Flashcards
(137 cards)
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
25. A good settling sludge would consist of what type of protozoa?
V2-7E-P123 (Fig 11.49)
Free swimmers and Stalk ciliates
26
26. You suspect your anaerobic digester is going sour. What is the best way to verify its condition? V2-7E-P191 (12.3-B)
VA/ALK ratio
27
27. What is considered normal operation of an aerobic digester?
V2-7E-P218 (12.62)
Settle and Decant as Needed
28
28. Low DO and nutrient deficiency will promote the growth of what?
V2-7E-P72 (11.62-4)
Filamentous bacteria
29
29. If you pump green sludge to a drying bed what chemical should be
applied? V2-7E-P221 (17.70)
Lime
30
30. What takes place in the stabilization tank in a contact stabilization plant? V2-7E-P112 (11.1011-3)
Absorption
31
31. Staffing is based on what? Chapter 62.699
Flow and type of Treatment
32
32. Why would you chlorinate the RAS line? V2-7E-P74 (11.66)
Control filamentous bacteria
33
33. What is the most common type of pond? V1-7E-P299 (9.2)
Facultative
34
34. The ash content in lab procedure is the same as?
Inorganic solids
35
35. Denitrification will cause what? V2-7E-P73 (11.65)
Rising sludge
36
36. Coliform count fail to meet standards, your chlorine supply is not the
problem. What most likely is? V1-7E-P372 (Tab 10.1 9)
Short circuiting and low contact time
37
37. How does temperature effect disinfection?.V1-7E-P352 (10.13)
Higher the temp the better the disinfection
38
38. How long should you wait after you make a process change before
making another change? V2-7E-P71 (
1 week
39
39. What is needed to calculate the F/M ratio? V2-7E-P16 (FN 3)
CBOD and MLVSS
40
40. What types of ponds are used after a trickling filter, activated sludge,
or BC plant? V1-7E-P297 (9.2)
Polishing pond
41
41. 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)
Manifold line is clogged
42
42. 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)
Increased organic load
43
43. Coliform bacteria are used for what? V2-7E-P551 (6.A)
Indicators of possible presence pathogenic organisms
44
44. CL2 combined with ammonia forms what? V1-7E-P350 (10.111)
Chloramines
45
45. It can be said that: V1-7E-P352 (10.13)
The lower the pH, the greater the disinfection
46
46. What is a quick test to check sludge condition? V2-7E-P517 (16.450 + FN 12)
Settlometer
47
47. What is the range of parameters to promote the best microorganism
growth for the Activated Sludge process?
2 ppm D.O., pH 7.0,75-95° F
48
48. What is the benefit of step feed aeration? V2-7E-P88 (11.83)
Treat higher flows in less space
49
49. 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)
Freezing of the lines
50
50. In an anaerobic digester, when the VA/ALK ratio starts to increase, what will be noticeable? V2-7E-P191 (12.3 B)
An increase in CO2 & decrease in pH
51
51. According to FAC Ch. 62-600, Domestic Wastewater Facilities, your job as an operator during major process breakdown is to?
Maintain competent documentation and record keeping
52
52. Short circuiting in a primary clarifier can be prevented by?
V1-7E-P135 (5.61)
Baffles
53
53. What do you do if you experience a plant upset due to a hydraulic overload?V2-7E-P70 (11.61 Condition 2)
Decrease WAS to maintain microorganism population
54
54. You have dark foam, high MLSS, slow settling sludge with a clear
effluent, you should?
Maintain 1-3 ft. sludge blanket, monitor MLSS, increase D.O. in necessary
55
55. If the blades on the Comminutor become dull, this can cause?
V1-7E-P41 (3.30 FN 7)
Pumps to become clogged with rags
56
56. 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?
The tank become hotter than the manifold
57
57. 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)
Check the plant data for the previous 3 weeks
58
58. If there is suspected leak with sulfur dioxide. What should you NOT use to detect it and why? V1-7E-P403 (10.921)
Soapy water/ Sulfuric acid
59
59. What take place in preliminary treatment? V1-7E-P34 (3.2)
Removes debris, sand, grit, freshens wastewater
60
60. What is the pH range of domestic wastewater producing the best
organic activity? V2-7E-P579 (8 A,B)
6-8
61
61. What is the proper gas mixture in an anaerobic digester under normal
operation? V2-7E-P191 (12.3 C)
70% Methane / 30% Carbon Dioxide
62
62. What is the liquid to gas expansion ratio of Chlorine? Florida Level *C° Workbook Chapter 8 P73
460: 1
63
63. A predominance of Nematodes, Rotifers, and Pin Floc in the effluent
indicates? V2-7E-P123 (Fig 11.49)
Old Sludge
64
64. What are the three groups of Protozoa commonly found in good activated sludge? V2-7E-P119 (11.1031-3)
Ciliates, Flagellates, & Amoeba
65
65. Which is an indication of Old sludge? V2-7E-P123 (Fig 11.49)
Low SVI & Low F/M ratio
66
66. How long does It take until the results of a COD test are avallable?
V2-7E-P541 (16.51-3)
4 hours
67
67. What are Saprophytic organisms? V2-7E-P148 (12.00 + FN 3)
Organisms that thrive on dead or decaying organic matter
68
68. What does a predominance of free swimming ciliates in the mixed
liquor indicate? V2-7E-P119 (11.1031-3)
A stable operation
69
69. Septic conditions in the collection system will cause the pH to.
V1-7E-P1 0-?
Decrease
70
70. Under what conditions will Filamentous organisms thrive?
| V2-7E-P119 (11.1031-3)
When D.O. is low
71
71. What is it called when the velocity is greater in some sections of a
clarifier than in others? V1-7E-P135 (5.61 2)
Short circuiting
72
72. What is the most desirable pH in a pond? V1-7E-P301 (9.3)
7.5
73
73. What nutrients are used by green algae? V1-7E-P294 (9.0)
Nitrogen and Phosphorous
74
74. When operating a pond, what tests should be performed on a regular
basis (1-2 times per week)? V1-7E-P309 (9.610 D)
D.O., pH, and Temperature
75
75. Excessive D.O. levels can cause?. V2,7E-P19 (11.02)
Pinpoint floc
76
76. Sludge pumped from a clarifier sump should be? V1-7E-P130 (5.3)
As thick as possible
77
77. What is indicated by a high SVI and slow settling? V2-7E-P60-1 (11.560-1)
Young sludge
78
78. What happens to the pH in a pond during the day when algae are
consuming carbon dioxide, producing oxygen? V1-7E-P299 (9.3)
Increases
79
79. The removal of settleable organic solids is an example of? V1-7E-P43 (3.5)
Primary Treatment
80
80. Which of the following is a cause of white foam? V2-7E-P49 (11.41) & P53 (11.501)
Activated Sludge Solids level too low
81
81. Which of the following may be the cause of Filamentous type bulking?
Septic influent wastewater
Low D.O. levels in the aeration tank
Oils & Grease
82
82. Which is a description of good solids in an aeration tank? V1-7E-P266 (8.26)
Golden to dark brown and granular
83
83. White fluffy foam indicates? V2-7E-P75 (11.67 4)
Low MLSS in aerator
| High F/M ratio
84
84. Which organisms will predominate when the F/M ratio is low?
V2-7E-P123 (Fig 11.49)
Rotifers
85
85. Which of the following is the most common short filament? V2-7E-P117 (11.1031-2b)
Nocardia
86
86. What is the proper ratio of nutrients in domestic wastewater? (BOD:
Nitrogen; Phosphorous; Iron)
100; 5/1/0.5
87
87. In which class are electrical fires? V2-7E-P303 (14.41)
C
88
88. What could be the cause of Nocardia and foaming? V2-7E-P127 (11.1052)
Industrial waste/toxic shock loading
89
89. Which organisms are indicators of the possible presence of
pathogens in water? V2-7E-P551 (6 A)
Coliform
90
90. Which modification of the activated sludge process requires the use of
two separate aeration tanks? V2-7E-P86-7 (11.81-2)
Contact Stabilization
| Krause
91
91. Which requires an Anoxic Zone for Denitrification? V2-7E-P90 (11.86)
Bardenpho
92
92. Which would be the best process to use when treating wastes from
canneries and dairies? V2-7E-P87 (11.82)
Krause
93
93. Which process would better handle a shock load? V2-7E-P88 (11.83)
Step-Feed
94
94. 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)
Complete Mix
95
95. Which process would best handle fluctuating flows? V2-7E-P93 (11.90)
Sequencing Batch Reactor
96
96. Where micro samples should be taken in a conventional activated sludge plant? V2-7E-P112 (11.1011)
At the effluent end of the aerator
97
97. What adjustment would need to be made if the F/M ratio is high?
V2-7E-P19 (11.02)
Increase D.O.
98
98. Which of the following could be a cause of bulking? V2-7E-P71 (11.62)
High F/M Ratio
99
99. What color is the foam that is produced when Nocardia are present?
V2-7E-P73 (11.66)
Brown
100
100. 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)
To avoid washout of activated sludge solids and culture microorganisms
101
101. What is formed when chlorine combines with water?
| V1-7E-P349 (10.10)
Hypochlorous Acid + Hydrochloric acid
102
102. What would a high SVI indicate? V2-7E-P60-4 (11.56-7)
High Organic Loading
Predominance of flagellates
High F/M ratio
103
103. 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)
Amoeba
104
104. What adjustment can be made to the primary clarifier to correct a rising sludge problem? V2-7E-P73 (11.65)
Remove a primary clarifier from service
105
105. How long records must be kept on site? Chapter 62.620
Three Years
106
106. The Initial Chlorine Demand during disinfection is caused by?
V1-7E-P350 (10.110)
Inorganic Material in the water
107
107. Which has the best disinfecting power when Hypochlorous acid and
Ammonia are combined? V1-7E-P350 (10.111)
Dichloramine
108
108. What is the maximum holding time for BOD .samples? V2-7E-P502 (Tab 16.4)
48 hours
109
109. As the VA/ALK ratio increases, the .
| - also increases? V2-7E-P191 (12.3 B)
Carbon Dioxide production
110
110. How can a Sulfur Dioxide leak be detected? V1-7E-P403 (10.921)
A rag soaked in strong ammonia
111
111. Why should a sludge line never be closed on both sides?
| V2-7E-P221 (12.70)
Pressure from gases could cause a line rupture
112
112. What is one cause of light colored foam in an aerator? V1-7E-P266 (8.252)
Low suspended solids
113
113. 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)
1
114
114. What is the maximum holding time for pH samples? V2-7E-P502 (Tab 16.4)
No holding time
115
115. What is a Class B fire? V2-7E-P303 (14.41)
Oil
116
116. Which of the following organisms are predominate in old sludge? V2-7E-P120 (11.1031-4)
Rotifers
117
117. Why should a positive displacement pump never be operated against a closed discharge valve? V2 7E-P371 (15.191)
Pressure will cause the pipe, pump or valve to rupture
118
118. What is the typical pH range of domestic wastewater entering a
treatment plant? V1 7E-P350 (10.111)
6.5-7.5
119
119. The removal of heavy inorganic solids is an example of? V1-7E-P41 (3.3)
Primary Treatment
120
120. Nocardia and foaming indicates? V2-7E-P117 (11.1031-2)
Low D.O. & Low F/M ratio
121
121. What is one cause of light-colored floating sludge solids on the secondary clarifier? V1-7E-P265 (8.252)
High aeration rates, decrease rate
122
122. At what temperature does a fusible plug in a chlorine cylinder melt?
V1-7E-P378 (10.500)
158°F to 165°F
123
123. According to D.E.P rules, when is discharge monitoring reports to be
filed by? Chapter 62.600
28th of the following month
124
124. How often should a primary clarifier be shut down for cleaning?
Every 12 months
125
125. Why is wastewater disinfected? V1-7E-P347(10.1)
To destroy pathogenic bacteria to safe levels
126
126. When pumping sludge to a digester it is best to pump? V2-7E-P185 (12.22)
Small amounts at frequent intervals
127
127. What type of sewer collects domestic waters from homes? V1-7E-P33 (3.10)
Sanitary
128
128. What conditions could occur when a sludge pump draws sludge too quickly? V2-7E-P185 (12.22)
Coning
129
129. What methods can be use to dispose of screenings? V1-7E-P71 (4.24)
Incineration and burial
130
130. 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?
Young sludge
131
131. How often should manholes be placed in the collection system for
access and maintenance? V1-7E-P34 (3.10)
300-500ft
132
132. When effluent enters the secondary clarifier with a SVI of 300 what is
likely to occur?
The sludge will settle evenly
133
133. Wasting rate changes should not exceed what % from one day to the
next? V2-7E-P55 (11.53)
10% - 15%
134
134. 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)
Spray scum blanket with water to soften it
135
135. What type of pond is used for waste that has not received any prior treatment? V1-7E-P297 (9.2)
Stabilization pond
136
136. Why would we treat the RAS line with chlorine? V2-7E-P72 (11.62-4)
To control filamentous bacteria
137
137. What is a representative portion of a sample called? V2-7E-P813 (definitions)
An aliquot
