Wastewater Management

Q. definition of aeration

Q.

Some students of class 7 were taken for an educational trip to Waste water treatment plant .The teacher explained the process of water treatment. Identify the correct order of the process.

Step I:The liquid material is passed through sedimentation tank where solid waste like faecal matter, sand, grit settles down.

Step II:This solid matter is then removed with the help of a scrapper. This is the sludge.

Step III: Waste water is passed through bar screens to remove big objects like cans, sticks, rags etc.

Step IV: A skimmer removes the floatable solids like oil, grease etc.

Step V: Air is pumped into clarified water to help aerobic bacteria to grow. The bacteria then consume the unwanted matter still present in clarified water.

Step VI: The clear water so obtained is called clarified water.

Step VII:The suspended microbes settle at the bottom & the water is removed from the top.

1. III, I, II, IV, V, VII, VI

2. I, II, III, IV, VI, V, VII

3. III, I, II, IV, VI, V, VII

4. I, II, III, IV, V, VI, VII

Q.

What is chlorination of water and how it works? Please explain with examples.

Q.

What are the various methods used to separate insoluble solid particles like dust or soil from a liquid mixture? Explain each one of them. [3 MARKS]

Q.

What is the reaction of ozone and potassium iodide?

Q.

Dried ____________ is used as manure.

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

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

Q.

Dried __________ is used as manure.

Q.

Question 6

Pick from the following one chemical which is used to disinfect water.
(a) Chlorine
(b) Washing soda
(c) Silica
(d) Coal

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 amongst the following is not an example for onsite sewage disposal system?

1. Chemical toilets
2. Wastewater treatment plant
3. Septic tanks
4. Compost pits

Q. What are the conventional methods used for the purification of water? [2 MARKS]

Q.

Sludge in separate tanks is decomposed to get biogas by

1. yeasts
2. 
   

   aerobic bacteria

3. 
   

   anaerobic bacteria

4. none of these

Q.

The components of a true solution can be separated by filtration.

1. True
2. False

Q.

The separation of solid waste from domestic sewage is known as __________.

1. slurry

2. sludge

3. humus

4. manure

Q.

Question 1
Fill in the blanks:
(a) Cleaning of water is a process of removing __.
(b) Wastewater released by houses is called __.
(c) Dried __ is used as manure.
(d) Drains get blocked by __ and __.

Q.

To kill any germs present in water, chlorine is commonly added to it.

1. True
2. False

Q. During _____ , sand and heavy dirt particles are allowed to settle down in a wastewater treatment plant.

1. Sedimentation
2. Screening
3. Aeration
4. Clarification

Q.

Question 4
Describe the steps involved in getting clarified water from wastewater.

Q.

23. (d) Do you think this water (muddy water after filtration) is now safe to drink? Why?

Q. You are on a field trip to a rural area. Thirsty and tired, you ask for a cup of water. Once you start drinking you smell chlorine in it. What would you infer?

1. It has added chemicals in it and is not fit for consumption
2. It is contaminated and should not be consumed
3. Added chlorine enrichs the taste of tap water
4. It has been disinfected and can be consumed.

Q. Select the compound used to purify water?

1. Sugar
2. Oil
3. Chlorine
4. Salt

Q. Cleaning of sewage is a process of removing ____ from it.

1. oxygen
2. vitamins
3. pollutants
4. minerals

Q. Arrange the steps involved in sewage disposal in correct order.

1. Transfer waste
2. Capture waste
3. Treatment
4. Hygienic storage
5. Reuse /Disposal

Q.

Find the correct sequence of processes used for purification of water.

1. Loading, Sedimentation, Filtration

2. Sedimentation, Loading, Filtration

3. Filtration, Loading, Sedimentation

4. Filtration, Sedimentation, Loading

Q. Describe the steps involved in getting clarified water from wastewater. [5 marks]

Q.

Sludge in separate tanks is decomposed to get biogas by

1. yeasts
2. 
   

   aerobic bacteria

3. 
   

   anaerobic bacteria

4. none of these

Q. Arrange the steps involved in sewage disposal in correct order.

1. Transfer waste
2. Capture waste
3. Treatment
4. Hygienic storage
5. Reuse /Disposal

Q. Describe the different sources of wastewater.

Q.

Water which looks clean still has disease carrying ______ and _______ impurities.