Worksheets With Solutions: Wastewater Management Class 7 Worksheet Science

Section A: Multiple Choice Questions

Correct Answer is Option (d)

Domestic, industrial and agricultural activities are all sources of wastewater.

Q.2. What is sewage?
(a) Clean water
(b) Wastewater from domestic activities
(c) Wastewater from industrial activities
(d) None of the above

Correct Answer is Option (b)
Sewage refers to wastewater from domestic activities such as washing, bathing, and flushing.

Q.3. Which of the following is a contaminant found in wastewater?
(a) Metals
(b) Pesticides
(c) Microorganisms
(d) All of the above

Correct Answer is Option (d)
Metals, pesticides, and microorganisms are all contaminants found in wastewater.

Q.4. What is eutrophication?
(a) The process of treating wastewater
(b) The process of adding nutrients to a body of water
(c) The process of removing nutrients from a body of water
(d) None of the above

Correct Answer is Option (b)
Eutrophication is the process of adding nutrients to a body of water, which can lead to excessive growth of algae and other aquatic plants.

Q.5. What is the primary purpose of a wastewater treatment plant?
(a) To produce clean water for drinking
(b) To remove contaminants from wastewater
(c) To recycle wastewater for industrial use
(d) None of the above

Correct Answer is Option (b)
The primary purpose of a wastewater treatment plant is to remove contaminants from wastewater before it is discharged into the environment.

Section B: Short Questions

The different sources of wastewater include domestic activities (such as washing, bathing, and flushing), industrial activities (such as manufacturing and mining), and agricultural activities (such as irrigation and livestock production).

Q.2. What are the contaminants found in wastewater?

The contaminants found in wastewater include metals, pesticides, microorganisms, and other pollutants.

Q.3. Explain the concept of eutrophication.

Eutrophication is the process of adding nutrients to a body of water, which can lead to excessive growth of algae and other aquatic plants. This can deplete oxygen levels in the water, leading to the death of fish and other aquatic organisms.

Q.4. What is the purpose of a wastewater treatment plant?

The purpose of a wastewater treatment plant is to remove contaminants from wastewater before it is discharged into the environment. This is done through a series of physical, chemical, and biological processes.

Q.5. How can sewage generation be controlled?

Sewage generation can be controlled by reducing water usage, repairing leaks, and using water-efficient appliances and fixtures.

Section C: Fill in the blanks

Q.1. __________ is the main source of wastewater in households.

Domestic use

Domestic use is the main source of wastewater in households, which includes activities such as washing, bathing, and cleaning.

Q.2. The sewage contains __________ that can harm the environment.

Contaminants

Sewage contains a range of contaminants, including harmful bacteria, viruses, and chemicals, which can harm the environment if not treated properly.

Q.3. The process of adding nutrients to a water body and causing excessive plant growth is called __________.

Eutrophication

Eutrophication is the process of adding nutrients to a water body and causing excessive plant growth, which can deplete oxygen levels and harm aquatic life.

Q.4. The __________ is responsible for collecting and transporting wastewater.

Sewer system
The sewer system is responsible for collecting and transporting wastewater from households and industries to the wastewater treatment plant.

Q.5. The process of removing large particles from wastewater is called __________.

Primary treatment
Primary treatment is the initial stage of wastewater treatment, which involves removing large particles such as gravel, sand, and debris from wastewater.

Section D: Match the column 

1. Tertiary treatment is the final stage of wastewater treatment, which involves removing nutrients and fine particles from the wastewater.
2. Secondary treatment involves removing organic matter and microorganisms from the wastewater.
3. Primary treatment involves physical and chemical processes such as sedimentation, flotation, and filtration.
4. Eutrophication is the process of adding nutrients to a water body and causing excessive plant growth.
5. Removing floating and suspended solids is one of the primary objectives of the secondary treatment process.

Section E: True or False 

False
Wastewater is mainly generated in households and industries, not just industries.

Q.2. The sewer system collects rainwater along with wastewater. 

False
These were system collects and transports only wastewater, not rainwater.

Q.3. Tertiary treatment is the final stage of wastewater treatment. 

True
Tertiary treatment is the final stage of wastewater treatment, which involves removing nutrients and fine particles from the wastewater.

Q.4. Alternative methods of sewage disposal are not required in rural areas. 

False
Alternative methods of sewage disposal are required in both rural and urban areas to ensure proper wastewater management.

Q.5. Improper management of sewage can lead to the spread of diseases. 

True
Improper management of sewage can lead to the spread of diseases such as cholera, typhoid, and hepatitis A.