Match the terms with the meanings. a) coagulation i) impurities percolate through layers of sand, charcoal and gravel b) sedimentation ii) substance that is left behind after wastewater is treated c) filtration iii) chlorine is added to the water before it goes to your home d) aeration iv) alum is added to the water causing dirt and another particles to stick together e) sludge v) water is sprayed into the air where it mixes with oxygen f) primary treatment vi) impurities settle to the bottom of the tank g) chlorination vii) stage at which solids are separated from liquids in wastewater treatment by using screens

a) coagulation iv) alum is added to the water causing dirt and other particles to stick together. It is the process in which dirt and floating particles get stuck together to form scum on addition of alum, which floats over the water surface. b) sedimentation vi) impurities settle to the bottom of the tank In this process the heavy particles settle down at the bottom of the tank to form sludge. c) filtration vii) stage at which solids are separated from liquids in wastewater treatment by using screens This process helps in removing the undissolved waste in water by passing wastewater through a porous substance which acts as a filter. d) aeration v) water is sprayed into the air where it mixes with oxygen Wastewater is exposed to air in this process, this adds oxygen to the wastewater and allows the gases trapped in it to escape. e) sludge ii) substance that is left behind after wastewater is treated Sludge is the solid waste left behind after the wastewater is treated. Sludge on decomposition produces biogas. f) primary treatment i) impurities percolate through layers of sand, charcoal and gravel In the primary treatment of wastewater materials that will either float or readily settle out by gravity are removed. g) chlorination iii) chlorine is added to the water before it goes to your home Chlorine is a good disinfectant, it is added to water to kill the harmful microorganism in water in chlorination. a) coagulation iv) alum is added to the water causing dirt and other particles to stick together. b) sedimentation vi) impurities settle to the bottom of the tank c) filtration vii) stage at which solids are separated from liquids in wastewater treatment by using screens d) aeration v) water is sprayed into the air where it mixes with oxygen e) sludge ii) substance that is left behind after wastewater is treated f) primary treatment i) impurities percolate through layers of sand, charcoal and gravel g) chlorination iii) chlorine is added to the water before it goes to your home

This is a process in which dirt and other floating particles get stuck together to form scum which floats over the water surface. This method is used in wastewater treatment to remove the suspended light impurities.

E M B I B E

New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

MEDIUM

7th CBSE

IMPORTANT

Earn 100

Which statement defines aeration?

7.69% studentsanswered this correctly

Important Questions on Journey of Wastewater

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7th CBSE

IMPORTANT

New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

This is a by-product of sewage treatment and can be decomposed to produce biogas.

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7th CBSE

IMPORTANT

New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

The chemical which is used to kill the harmful microorganisms present in water is

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New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

The process in which alum is added to water that causes dirt and other particles to stick together is known as

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7th CBSE

IMPORTANT

New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

Which of the following is not a water-borne disease?

Note: The options given in the textbook seems to be wrong, the correct options are as follows;

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New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 1

Our body is composed of about 75% of

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7th CBSE

IMPORTANT

New Science Spark Book 7>Chapter 19 - Journey of Wastewater>Put on your THINKING CAP!>Q 2

Match the terms with the meanings.

a) coagulation	i) impurities percolate through layers of sand, charcoal and gravel
b) sedimentation	ii) substance that is left behind after wastewater is treated
c) filtration	iii) chlorine is added to the water before it goes to your home
d) aeration	iv) alum is added to the water causing dirt and another particles to stick together
e) sludge	v) water is sprayed into the air where it mixes with oxygen
f) primary treatment	vi) impurities settle to the bottom of the tank
g) chlorination	vii) stage at which solids are separated from liquids in wastewater treatment by using screens