Wastewater Treatment

Q. Activated sludge contains ______ percent water.

1. ninety-seven
2. sixty-six
3. thirty-three
4. seventy-one

Q.

Why is air pumped into the clarified water? [2 MARKS]

Q. Which among the following is removed using a scraper during wastewater treatment?

1. Grease
2. Plastic
3. Sludge
4. Sand

Q. Activated sludge is the sludge with air in it. True or False?

1. False
2. True

Q.

Which among the following are the by-products of wastewater treatment?

1. Carbon dioxide and ozone

2. Carbon monoxide and sludge

3. Biogas and sludge

4. Biogas and ozone

Q. What would happen if there were no microbes that break down wastes in sewage?

Q. Which of the following is the last step in the wastewater treatment?

1. Screening
2. Chlorination
3. Segregation
4. Aeration

Q. Which major step in wastewater treatment prepares the wastewater for treatment by physically removing the majority of solid material?

1. Primary treatment
2. Tertiary treatment
3. Chlorination of water
4. Secondary treatment

Q.

What happens when

1. Cooking medium is made to flow down a drain
2. Insecticide motor oil paints are poured down the drain
3. Tea leaves cotton swabs and old soft toys are thrown into the drain

Q. The process of removing oil and grease from sewage in a wastewater treatment plant is known as ___.

1. aeration
2. screening
3. skimming
4. filtration

Q. Which of the following chemicals are used to disinfect water in a wastewater treatment plant?

1. Ozone
2. Chlorine
3. Hydrogen
4. Phosphate

Q.

When treating sewage, which of the following options gives the correct order in which contaminants are removed?

1. Plastic bags $\to$ bacteria $\to$ suspended solids $\to$ heavy metals

2. Suspended solids $\to$ heavy metals $\to$ plastic bags $\to$ bacteria

3. Plastic bags $\to$ suspended solids $\to$ heavy metals $\to$ bacteria

4. Bacteria $\to$ heavy metals $\to$ suspended solids $\to$ plastic bags

Q. Which of the following is not used in wastewater treatment?

1. Air
2. Chlorine
3. Ozone
4. Biogas

Q.

If untreated sewage is discharged into water bodies it will clean the water resources.

1. True

2. False

Q. In a wastewater treatment plant, which of the following contaminants can be removed using a bar screen?

1. Oil and grease
2. Grit and pebbles
3. Cans and rags
4. Bacteria and faeces

Q. Air is passed through clarified water in a wastewater treatment plant to:

1. increase the nitrogen content.
2. help aerobic bacteria to grow.
3. help anaerobic bacteria to grow.
4. disinfect wastewater.

Q. Which of the following can be used to produce electricity?

1. Biogas
2. Grit
3. Urea
4. Pesticides

Q. Which among the following is removed using a scraper during wastewater treatment?

1. Grease
2. Plastic
3. Sludge
4. Sand

Q. Arrange the processes involved in a correct sequence that is followed in the wastewater treatment plant.

1. Chemical $\to$ biological $\to$ physical
2. Biological $\to$ chemical $\to$ physical
3. Physical $\to$ biological $\to$ chemical
4. Biological $\to$ physical $\to$ chemical

Q.

Which of the following steps can be taken by an individual to help in water management?

1. Turn off the tap while brushing

2. Not washing clothes

3. Mopping the floor instead of washing

4. Setting up sewage treatment plant