Wastewater Treatment Quiz
Answers
1.
• Name the 3 steps of the wastewater
treatment plan.
• 1. Primary (sedimentation/flotation)
• 2. Secondary (biological)
• 3. Advanced
2.
• What is the purpose of the primary treatment
step?
• Remove things that float and sink
3.
• What is the purpose of the secondary step?
• Eat food and ammonia
4.
• What is the purpose of the advanced
treatment step?
• Filter(purify) & disinfect(clean)
5.
• Which step is this? What is the name?
Advanced treatment/Filter/ Step #3
6.
• Which step is this? What is the name?
Primary/Flotation & Sedimentation
7.
• Which step is this? What is the name?
Secondary/Biological/Aeration
8.
• What is the path of wastewater, starting from
our homes?
Pipes Wastewater facility/Treatment Plant 
LA River/River  Long Beach/Ocean
9.
• Why is important to not flush down toxic
chemicals like drano down the toilet?
Doesn’t hurt microorganisms
10.
• What are the 4 tests that a wastewater
treatment plant does on the water at various
steps of he process?
pH
Ammonia
COD (Chemical Oxygen Demand)
Turbidity
11.
• Explain what the pH test is used for
Measure acidity/basicity
Measure acid or base
12.
• The pH scale goes from ___0 or_1_ to
___14___. The most acidic being the
__lower__ numbers.
13.
• Why is it important to maintain a wastewater
pH between 6.6-8.5?
Doesn’t hurt the microorganisms
14.
• Explain what the purpose of the ammonia test
is
Measure ammonia levels
15.
• What is the main source of ammonia in our
wastewater?
Urine/Pee/Urea
16.
• Name the 2 reasons that ammonia is bad
1. Toxic
2. Oxygen goes down when bacteria eat it
17.
• What is the process of bacteria eating the
ammonia and turning it into a nitrate called?
Nitrification
18.
• Why do we need to dilute the wastewater
sample by 50% before using the ammonia
test?
Because the Ammonia test only tests between
0-6
• What do you need to do afterwards to
account for the 50% dilution?
Multiply by 2 at the end
19.
• Explain what the turbidity test is used for
How clear/murky/dirty/cloudy the water is or
How much sediment/suspended particles in
water
20.
• Why is turbidity bad for fish?
Prevents them from absorbing oxygen through
gills by blocking their gills
21.
• What instrument do we use to measure
turbidity?
Colorimeter
22.
• Why do we cover the colorimeter when
reading the blank and sample?
To prevent light from entering the
source/sample
23.
• Why do we need to blank the colorimeter
before using?
So colorimeter knows what “zero” is
To clear the colorimeter
24.
• Explain what the Chemical Oxygen Demand
test is used for
To test how much oxygen in water
Measure how much dissolved oxygen
25.
• Explain the cause and effect of eutrophication.
Cause: Food and ammonia in water
Effect: Dead zones (no oxygen)
26.
• What are the measuring units of pH, ammonia
levels and turbidity?
pH: None
Ammonia: mg/L
Turbidity: FAUs
27.
• A pH of 5 is acidic/basic?
28.
• Does coffee increase or decrease the
turbidity?
29.
• Between the original wastewater and after
primary treatment, what happened to
– the pH? Stayed same
– The turbidity? Increased, because things dissolved
– Ammonia level? Stayed same
If changed, explain why.
30.
• Between the primary treatment and after
secondary treatment, what happened to
– the pH? same
– The turbidity? Increased, because organisms
populated
– Ammonia level? Decreased, microorganisms ate it
If changed, explain why.
31.
• Between the secondary treatment and after
advanced treatment, what happened to
– the pH? same
– The turbidity? Decreased, filtered it
– Ammonia level? Decreased, microoganisms ate
If changed, explain why.
32.
• What kind of organisms were found in the
activated sludge?
Pathogens
Viruses
Bacteria
Protozoa
Microorganisms
Fungi Algae
Microbes
33.
• Why was it important to maintain oxygen
levels during the secondary treatment?
Microorganisms don’t die while eating food and
ammonia
Maintain constant oxygen level
Microroganisms continue to clean water
34.
• What is the difference between aerobic and
anaerobic bacteria? What kind of bacteria are
in the sludge?
Aerobic- need oxygen
Anaerobic- doesn’t need oxygen
Sludge= Aerobic
35.
• What is the purpose of Aluminum Sulfate?
Make solids sink
More sedimentation
36.
• Advanced treatment involves the following 2
steps:
1.Filtration
2. Disinfection (chlorination/UV)
37.
• What does the wastewater facility use to
disinfect water? (2 options)
1. Chlorination
2. UV Radiation
38.
• How does the plant remove chlorine from the
water?
• Dechlorination