Answer the following questions in brief:
(1)What is the difference between drinking water and river water?
Ans.
i) Drinking water undergoes the treatment process to meet safety standards, removing impurities.
ii) River water is natural, containing sediments, microbes and pollutants.
iii) Treatment ensures drinking water is safe and clean.
(2)Why is it said that untreated water is not suitable for drinking?
Ans.
i) Untreated water may contain harmful microorganisms, parasites, and contaminants that can cause
waterborne disease.
ii) Treatment processes remove impurities, ensuring safe drinking water by eliminating potential health
risk.
(3)Which water purifier tools are used in house? Describe them.
Ans.
i) Common water purifiers for homes include activated carbon filters, reverse osmosis
systems and UV purifiers.
ii) Activated carbon removes impurities, RO filters out contaminants and UV kills bacteria
and viruses.
iii) Additionally, sediment filters are obtained used in household water purifiers to trap
larger particles like sand and rust.
(4)What are the important stages implemented in water purification?
Ans.
i) Water purification involves stages such as coagulation, sedimentation, filtration,
disinfection and sometimes additional treatments like desalination.
ii) These process removes impurities, ensuring safe and clean drinking water.
These are the important stages implemented in water purification.
(5)How is water purification processes done for big cities/ villages? write briefly.
Ans.
i) Water purification for large scale communities involves centralised treatment plants.
ii) RO water undergoes processes like coagulation, sedimentation, filtration and disinfection to
meet quality standards before distribution to the household.
(6) What are the advantages and disadvantages of purifying water with UV rays?
Ans.
i) Advantages of UV water purification:
Effective against bacteria and viruses , no chemical addition .
ii) Disadvantages :
Ineffective against some contaminants, doesn't remove particles , and requires electricity for
operation