Wastewater

Question 1

What are 3 types of water pollution?

Answer 1

1. Suspended Materials
   a) large objects
   b) particulate matter
2. Dissolved Materials
   a) organics
   b) N, P, low organics
   c) inorganics
3. Microbes and Viruses

Question 2

What are 3 components of treatment?

Answer 2

1. Physical Components
2. Chemical Components
3. Biological Components

Question 3

What is the wastewater treatment sequence?

Answer 3

1. Screening: remove large debris
2. Primary Classification: separates suspended solids via sedimentation
3. Activated Sludge Process: uses microbial activity to degrade organic material
4. UV Disinfection: kills pathogens in water

Question 4

What is BOD and what does it indicate?

Answer 4

• measures the amount of oxygen required by microorganisms to decompose organic matter in water
• indicates level of biodegradable pollution

Question 5

What is COD?

Answer 5

• measures the amount of oxygen required to chemically oxidize organic and inorganic matter in water

Question 6

How does the COD process work?

Answer 6

Wastewater sample in mixed with the oxidant and boiled using reflux for 3 hours. The remaining dichromate is measured by titration

Question 7

Describe a procedure to determine 5 day BOD

Answer 7

1. Sample Collection
2. Dilution
3. Seeding (if required)
4. Initial DO measurement
5. Incubation
6. Final DO measurement
7. Calculate BOD = Doi - Dof