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?

pHAmmoniaCOD (Chemical Oxygen Demand)Turbidity

11.

• Explain what the pH test is used for

Measure acidity/basicityMeasure 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. Toxic2. 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” isTo clear the colorimeter

24.

• Explain what the Chemical Oxygen Demand test is used for

To test how much oxygen in waterMeasure how much dissolved oxygen

25.

• Explain the cause and effect of eutrophication.

Cause: Food and ammonia in waterEffect: Dead zones (no oxygen)

26.

• What are the measuring units of pH, ammonia levels and turbidity?

pH: NoneAmmonia: mg/LTurbidity: 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?

PathogensVirusesBacteriaProtozoaMicroorganismsFungi AlgaeMicrobes

33.

• Why was it important to maintain oxygen levels during the secondary treatment?

Microorganisms don’t die while eating food and ammoniaMaintain constant oxygen levelMicroroganisms continue to clean water

34.

• What is the difference between aerobic and anaerobic bacteria? What kind of bacteria are in the sludge?

Aerobic- need oxygenAnaerobic- doesn’t need oxygen

Sludge= Aerobic

35.

• What is the purpose of Aluminum Sulfate?

Make solids sinkMore sedimentation

36.

• Advanced treatment involves the following 2 steps:

1.Filtration2. Disinfection (chlorination/UV)

37.

• What does the wastewater facility use to disinfect water? (2 options)

1. Chlorination2. UV Radiation

38.

• How does the plant remove chlorine from the water?

• Dechlorination