Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PE Exam Civil Water Resources > Wastewater > Flashcards

Wastewater Flashcards

(89 cards)

Start Studying
1
Q

Why is mechanical ventilation required in a lift station?

A

Waste water can create toxic gas, the ventilation protects workers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

inflow that rapidly increases shortly after teh start of a storm and decreases quickly after the conlcusion of the storm is called

A

Direct inflow -

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the characteristics of Delayed inflow?

A

Decreasing gradually after the conclusion of a storm and after the peak inflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe peak inflow

A

ITs the largest rate difference in an hour between the storm event flow and the dry weather flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is estimated inflow?

A

the calculated approximation of the inflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of settling behavior is the non-interactive settling of particles from a dilute suspension that typically occurs during grit and sand removal?

A

Discrete settling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does TKN stand for and what are the components of it?

A

Total Kjeldahl Nitrogen,

Organic nitrogen and Inorganic ammonia and ammonium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe Biogas

A

It is the product of anaerobic digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is biogas composed of?

A

Methane
Hydrogen Sulfide
Carbon Dioxide
trace amounts of Nitrogen, oxygen and volatile hydrocarbons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the four stages of anaerobic digestion

A

Hydrolysis, acidogenesis, acetogenesis and methanogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 things to consider when designing a system for disinfecting a waste water treatment

A

The quality of the inflow water that is disinfected
the potential byproducts of disinfection
The effectiveness of the disinfection process for eliminating pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the chemical formula for Ozone?

A

O3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how is oxygen formed into Ozone for treatment?

A

Oxygen is passed through a high voltage potential to form O3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Clear water in a sewer collection system is likely causes by what?

A

infiltration from a high-water table

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Dry weather flow?

A

is the flow of wastewater in a sanitary sewer system when there are periods of dry weather that have minimum inflow and infiltration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When does Aeration take place?

A

in secondary treatement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do Grit removal, shredding and screening all have in common

A

They are all part of the preliminary treatement of wastewater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name three things that affect the efficiency of a primary sedimentation

A

The shape of the tank
The type of waste water entering
the tank capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

name three advantages of the trickling filter

A

cheap method of oxygen delivery
Construction costs are low
the system can be made non-electric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why does temperate matter for a trickling filter?

A

the media is exposed to the elements, extreme hot and cold weather can make the treatment less effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what causes nitrification happen? and name three things that affect the rate of nitrification

A

it occurs because of microbes, which are sensative to temperature and the oxygen levels ( too low it will be seriously affected) lastly pH - which needs to be 8-9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define Eutrophication

A

the process of enriching an ecosystem with natural or chemical nutrients that results in the dense growth of algae and other organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What chemical/ nutrient goes hand and hand with Eutrophication

A

Phosphates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the most common chemicals that remove phosphorus?

A

Metal salts
Aluminum Sulfate
Ferrous sulfate
Ferrous chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Name 3 treatment technologies to remove phosphorus and briefly describe each
Physical - Some phosphorus can be removed from the physical filtration of particulate matter or by using different types of membranes Chemical - different types of metal salts can be added to the influent to precipitate phosphorus Biological - this occurs when biological systems consume phosphorus
26
Which type of sludge is most commonly thickened by a centrifugal thickener, and why?
Secondary Sludge, secondary sludge has a lack of bulkly, stringy materials that can potentially cause clogging unlike Primary Sludge
27
Does incineration of disposed sludge kill pathogens?
yes
28
what is a drawback to sludge incineration?
the cost of heating up sludge is high because sludge typically has a high heat capacity
29
Name 4 components required for composting
Carbon, oxygen, nitrogen and water
30
What component of composting is used by microbes for energy?
Carbon
31
What component of composting critical in the decomposition process to oxidize another component of the compost
Oxygen oxidizes carbon in this process
32
What component of composting helps the organisms multiply
Nitrogen
33
What component of composting helps the system form going anaerobic?
Water
34
what impact does Nitrogen have on drying bed performance?
NONE
35
Name 3 things that impact drying bed performance?
Climate/humidity quality of the sludge and depth of the sludge layers
36
Name 3 disadvantages of thermophilic aerobic digestion
high initial cost Complex process to operate Large free board requirement
37
describe thermophilic aerobic digestion
finsih this
38
what is the most common form of waste water disinfection in America and what is the main disadvantage
Chlorination, the byproducts can produce harmful carcinogenic compounds
39
how does effluent polishing affect filter management?
filters must be backwashed frequently, this is because you must ensure that suspended solids present do not cause the bed to develop anaerobic or septic conditions
40
is Aeration a type of disinfection?
No, it is used to remove dissolved gases like Carbon dioxide and oxidize dissolved metals
41
Is Nitrification an anaerobic process?
NO, it is an aerobic process
42
Describe Nitrification
The process of nitrification is the compound biological oxidation of ammonia to nitrite, then nitrite to nitrate. This process is lead by tiny groups of archaea and autotrophic bacteria (A biological process by which nitrate is converted to nitrogen gas)
43
Name two mechanisms used to remove fat and grease, and how it works
Skimmers and Air Blowers, Fat and grease are hydrophobic they float on the surface of clarifiers
44
Why cant grease collected from grit removers or settling tanks be re-used as industrial and commercial lubricants?
the possibility that it has been exposed to many pathogens, and making it potentially toxic is very high
45
is Ammonia an oxidized form of Nitrogen?
No
46
name three oxidized forms of nitrogen?
Nitrogen gas, Nitrate, Ammonium nitrate
47
Name 3 major sources of phosphorus in influent wastewater
Industrial waste, Detergents and cleaners
48
Describe a lagoon
Lagoons hold sludge and work via evaporation, there have no underdrain so it takes a long time to dry.
49
Why is thickened sludge the optimum feed to a digester?
It has a low amount of of heat required It decreases the return hydraulic load It decreases the potential impact of alkalinity changes
50
Does Biological nutrient removal, remove chlorine?
NO, chlorine serves to kill microorganisms
51
what type of filtration is needed to filter out Sugar and nitrogen?
Nanofiltration
52
the intensity of odors are affected by?
pH and temperature
53
For the sedimentation basins, Why are design overflow rates restricted?
To prevent up flow density current that would transport the solids over the weirs and out of the basin
54
What is the difference between Aerobic and Anaerobic digestion
55
what is Biogas and how is it produced in Wastewater
56
What is Coliform bacteria
57
What does Coliform bacteria usually indicate?
58
Name the 4 types of settling and what order they are (Region)
59
Define Compressive settling
60
What is Delayed inflow in wastewater system
61
What is direct inflow in wastewater system
62
What is Dissolved air flotation and how does it work?
63
what is Total kjeldahl Nitrogen (TKN)method
64
what is a Diurnal cycle
65
what is anaerobic bacteria
66
what is Escherichia Coliform
67
what is a neutal pH
7.1
68
the higher the pH the more_____ ?
Alkaline, alkalinity
69
The lower the pH the more_____?
Acidic, acidity
70
What is a Polyelectrolytes
Synthetic chemicals used as a coagulant aid.
71
what is the proper pH range for digested sludge?
6.8-7.2
72
what is an Aerobe? and who is its counterpoint?
73
define Aliquot
Portion of a sample. Often an equally divided portion of a sample.
74
defione Anoxic
Oxygen deficient or lacking sufficient oxygen
75
what is the difference between, alkaline, acid, and base
76
what is sludge Bulking?
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process bulking is usually caused by filamentous bacteria or bound water.
77
what is a Comminutor
A device used to reduce the size of the solid chunks in wastewater by shredding (comminuting). The shredding action is like many scissors cutting or chopping to shreds all the large influent solids material in the wastewater.
78
What is Detritus and whats another name for it?
The heavy, coarse mixture of grit and organic material carried by wastewater. (also called grit)
79
What is Elutriation
The washing of digested sludge with fresh water, plant effluent or other wastewater. The goal is to remove fine particles and/or the alkalinity in the sludge. This process reduces the demand for conditioning chemicals and improves settling or filtering characteristics of the sludge.
80
What are Filamentous organism and what do they cause in waste water treatmenet?
Organisms that grow in a thread or filamentous form. Common types are Thiothrix and Actinomycetes. A common cause of sludge bulking in the activated sludge process.
81
what causes a septic condition, and what happens if it is severe?
A condition produced by anaerobic bacteria. If severe, the wastewater produces hydrogensulfide, turns black, gives off foul odors, contains little or no dissolved oxygen, and creates a high oxygen demand.
82
what is a Supernatant?
Liquid removed from settling sludge. Supernatant commonly refers to the liquid between the sludge on the bottom and the scum on the surface of an anaerobic digester. The liquid is usually returned to the influent wet well or to the primary clarifier.
83
what is a Zoogleal Mass?
Jelly like masses of bacteria found in both the trickling filter and activated sludge processes - (similar to biomass)
84
what is a helminths?
"high order" animals, their eggs present in sewage can cause illness example: Fluke(trematoades), tape worm(cestodes), round worm (nematoads)
85
What is an Imhoff Cone
86
What is advection
87
What is disperson
88
What is conversion in WW, changing of Concentration refering to
89
three types of lake circulations and exmaple
1. Holomictic Lakes - complete ciruclation over the whole water column 2. Meromictic LAkes - Circulation does not occur at the whole water column 3. Amictic Lakes - no circulation

PE Exam Civil Water Resources (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions