DAILY WATER CONDITION

PRABHJOT SINGH (PABO)

As water in streams and rivers flows along,it picks up two kinds of impurities--- soluble and insoluble.Soluble impurities are salt and minerals that dissolve in water.Insoluble impurities are stone,sand mud,chalk and several other substances.sometimes water also contains germs which cause diseases.Many soluble and insoluble impurities are introduced in water when waste from factories is dumped in rivers,lakes or seas. To make water suitable for drinking,all harmful impurities and diseases-caused germs must be removed from it.Most soluble impurities are not harmful and are not removed to make water fit for drinking.

A total of 1094 water samples from 326 springs, 207 streams, 183 dug wells, 151 piped supplies, 90 tube wells, 75 hand pumps, 60 rivers and 2 lakes were collected from eight northern and six north-eastern districts of India. Samples were analysed to assess their potability by estimating the level of heavy metals and bacterial (coliform and faecal coliform) contaminations.
Iron was found in a maximum number (53%) of water samples from hand pumps, followed by lead in 43% of the tube wells, chromium in 16% of dug wells, cadmium in 13% of streams and manganese in 7% of hand pumps above their maximum admissible concentrations (MACs).
Maximum metal pollution has been observed in a considerable number of water samples from Doda, followed by Almora, Mirzapur and Bankura. Hand pump water samples exhibited maximum metal pollution followed by dug well, spring, stream and river water samples.
Contamination of coliform and/or faecal coliform bacteria ranged between 41% and 67% of water samples from open water sources but it was also less, i.e. 6–15% of water samples from tube wells and hand pumps. In general, 42–85% of water samples from districts surveyed, except from Jammu (18%) and Mirzapur (27%), were found to be bacteriologically unsatisfactory. Since toxic metals and pathogenic bacteria pose a risk to public health, monitoring of drinking water sources is required.
PH LEVEL OF WATER IN 4 DIFFERENT ZONES

South-7.4
West-7.2 to 7.6
North-6.4 to 7.6
East-9
USE OF WATER PURIFICATION SYSTEM
REMOVING INSOLUBLE IMPURITIES
Insoluble impurities can be removed from water in two ways:
1) By Sedimentation and Decantation.
2) By Filtration.
SEDIMENTATION
Mix some chalk powder in water in a glass and stir it.The chalk spreads in the water and makes it milky.Allow the glass to stand still for 5-10 minutes.The insoluble pieces of chalk slowly settle down at the bottom of the glass.There will be clear water on top.. Thus this process ,known as sedimentation removes the insoluble impurities which settle at the bottom to form a sediment..
DECANTATION
Decantation consists of slowly pouring off the clear water at the top,into another vessel. The sediment gets left behind.
FILTRATION
Tea is filtered through a sieve to remove the tea leaves.But the sieve cannot be used to filter water.This is because the impure particles are of very small size and will pass through the sieve.For this we need a filter paper which works like a sieve with very fine holes..
Take a round filter paper.Fold it twice to form a triangle.Open it out to form a cone.Fit this cone in a glass funnel.pour the muddy water carefully into the cone.Clear water will collect in the vessel kept below the funnel.The impurities will be left behind on the filter paper.
REMOVE SOLUBLE IMPURITIES
It is more difficult and expensive to remove soluble impurities from water.For this water has to be heated to evaporate it.The steam is then condensed to give pure water.
EVAPORTION
Dissolve two teaspoonful of sugar in half a glass of water.Keep a water in dish and heat it.The water evaporates.Keep heating untill all the water has evaporated.You will find that the dissolved sugar is left behind in the dish.
DISTILATION
In evaporation,the water is lost in the form o water vapour.To get pure water we have to cool the water vapour so that it condenses to form water again.This is done by heating the water in the retort.The water vapour passes through a tube into another flask.This flask is kept cool by cold water.Here the water vapour condenses.The water collected in this way is called distiled water