1. Wastewater Treatment Quiz Answers

2. 1. Name the 3 steps of the wastewater treatment plan.
1. Primary (sedimentation/flotation)
2. Secondary (biological)
3. Advanced

3. 2. What is the purpose of the primary treatment step?
Remove things that float and sink

4. 3.
What is the purpose of the secondary step?
Eat food and ammonia

5. 4. What is the purpose of the advanced treatment step?
Filter(purify) & disinfect(clean)

6. 5.
Which step is this? What is the name? Advanced treatment/Filter/ Step #3

7. 6.
Which step is this? What is the name? Primary/Flotation & Sedimentation

8. 7.
Which step is this? What is the name? Secondary/Biological/Aeration

9. 8. What is the path of wastewater, starting from our homes?
Pipes Wastewater facility/Treatment Plant  LA River/River  Long Beach/Ocean

10. 9.
Why is important to not flush down toxic chemicals like drano down the toilet?
Doesn’t hurt microorganisms

11. 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

12. 11. Explain what the pH test is used for Measure acidity/basicity
Measure acid or base

13. 12.
The pH scale goes from ___0 or_1_ to ___14___. The most acidic being the __lower__ numbers.

14. 13. Why is it important to maintain a wastewater pH between 6.6-8.5?
Doesn’t hurt the microorganisms

15. 14. Explain what the purpose of the ammonia test is
Measure ammonia levels

16. 15. What is the main source of ammonia in our wastewater?
Urine/Pee/Urea

17. 16. Name the 2 reasons that ammonia is bad Toxic
Oxygen goes down when bacteria eat it

18. 17.
What is the process of bacteria eating the ammonia and turning it into a nitrate called?
Nitrification

19. 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

20. 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

21. 20. Why is turbidity bad for fish?
Prevents them from absorbing oxygen through gills by blocking their gills

22. 21.
What instrument do we use to measure turbidity?
Colorimeter

23. 22. Why do we cover the colorimeter when reading the blank and sample?
To prevent light from entering the source/sample

24. 23. Why do we need to blank the colorimeter before using?
So colorimeter knows what “zero” is
To clear the colorimeter

25. 24. Explain what the Chemical Oxygen Demand test is used for
To test how much oxygen in water
Measure how much dissolved oxygen

26. 25. Explain the cause and effect of eutrophication.
Cause: Food and ammonia in water
Effect: Dead zones (no oxygen)

27. 26. What are the measuring units of pH, ammonia levels and turbidity?
pH: None
Ammonia: mg/L
Turbidity: FAUs

28. 27.
A pH of 5 is acidic/basic?

29. 28.
Does coffee increase or decrease the turbidity?

30. 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.

31. 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.

32. 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.

33. 32. What kind of organisms were found in the activated sludge?
Pathogens
Viruses
Bacteria
Protozoa
Microorganisms
Fungi Algae
Microbes

34. 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

35. 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

36. 35. What is the purpose of Aluminum Sulfate? Make solids sink
More sedimentation

37. 36. Advanced treatment involves the following 2 steps: 1.Filtration
2. Disinfection (chlorination/UV)

38. 37.
What does the wastewater facility use to disinfect water? (2 options)
Chlorination
UV Radiation

39. 38.
How does the plant remove chlorine from the water?
Dechlorination