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 Toxic 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) Chlorination UV Radiation

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