Question

In order to have safe drinking water, it should be
A. filtered
B. boiled
C. freeze
D. both A and B

Answer 1

Hint: To avoid contaminated drinking water, various kinds of technique or technology available to remove toxins and microbes from the water. In water treatment plants various kinds of procedures are used to remove pollutants from the water such as coagulants, bleaching powder and ozone gas.

Complete answer:
To remove the microbial contamination from the contaminated water or to achieve safe drinking water, one of the most conventional methods used by people is the boiling method. Filtration process is achieved using a different kind of membrane or layer through which only water can pass out and the rest of the material stays on the layer.

Some of the techniques utilised for safe drinking water, such as reverse osmosis in this water is moved from lower gradient level to higher gradient level via semipermeable membrane. It is a very costly method to achieve safe water.

> Electro dialysis: In this method water is passed through electrode discharge, through which electricity is passed, this electric current is able to capture dissolve material of the water.

> Disinfectant: Chlorine is used as disinfectant material to purify the water, in this chlorine is formed hypochlorite which can effectively kill all the microbes in water by damaging the cell membrane of microbes.

> Boiling: It is the conventional method used by many people to get pure or safe drinking water, in which water is boiled for several minutes at specific temperature to ensure the elimination of all microbes.

Hence, the correct answer is option (D).

Note: CPCB set certain standards to ensure the elimination of water pollution. The water pollution act came in 1974. The pollution is characterised by the presence of biological pollutants like coliform bacteria or organic waste and chemical pollutants like inorganic material like heavy metal and acid or base. Physical pollution like rise in temperature of water bodies which alter the environment of water.