Physical parameters

1.Turbidity

However, Turbidity is the amount of suspended solids (in mg) present in 1 litre of water. Methods of measuring turbidity are descibe as:-

A.Turbidity Rod

B.Jackson Turbiditymeter (used when turbidity > 25 units)

C.Baylis Turbiditymeter

D.Nephelometer (Most precise, commonly used these days, used when turbidity < 1 unit)

Units: NTU or JTU or ppm or mg/l

2.Colour

Whereas, Color is measured with the help of Tintometer. However, what we measure here is the 1mg of platinum cobalt in the form of chloroplatinate ion.

3.Taste and Odour

Taste and Odour is also measured with the help of Osmoscope.

Units: TON (Threshold Odour Number)

Dilution factor = (Vs+Vw)/Vs

whereas Vs = volume of raw water (smelling water) and Vw = volume of distilled water.

4.Temperature

The temperature of water should be certainly between 10 to 25 degree celsius.

5.Specific Conductivity

Determined by portable dionic water tester. Meanwhile, it is expressed as micro mohs per cm at 25 degree C.

Chemical parameters

1.Solids

a. Total solids

Total solids = dissolved solids + suspended solids

It is determined by evaporating 1 lt. of water and weighing the solids left.

Units: mg/lt.

b. Suspended solids

Suspended solids is determined by following process-

Firstly take a whatman filter paper and weigh it. Then pass the raw water through it. Now the suspended solid is stuck over filter paper. It is weighted. Then weight of filter paper is subtracted. Therefore weight of suspended solids is obtained,

c. Dissolved solids

However, Dissolved solids = Total solids – Suspended solids

2.Ph value

PH = -log [H+]

POH = -log [OH-]

[H+] [OH-] = 10^(-14)

PH + POH = 14

3.Hardness

a. CH (Carbonate Hardness)

Carbonate Hardness is also known as Temporary hardness. Although, Formed by carbonates and bicarbonates of calcium and magnesium.

b. NCH (Non Carbonate Hardness)

Non Carbonate Hardness is also known as Permanent hardness. Although, Formed by chlorides and sulphates of calcium and magnesium.

4.Permissible limits and Rejection limits

5.Nitrogen content

Firstly, Free ammonia (0.15 mg/lt.). Secondly, Organic ammonia (0.30 mg/lt.). Thirdly, Nitrite (nil). At lastly, Nitrate (45 mg/lt.)

Moreover, Kjedahl Ammonia = free ammonia + organic ammonia

Also, Excess of nitrate causes Blue Baby Disease / Blue Baby Syndrome (Methemoglobinemia).

Biological parameters

1.MPN (Most Probable Number)

a) Presumptive Test

Therefore, Chemical used in this test is lactose broth. Firstly, Incubated for 24 hours at 35 degree Celsius

b) Confirmative Test

Therefore, Chemical used in this test is lactose green bile broth. In the same way, incubated for 24 hours at 35 degree Celsius

c) Completed Test

Thomson’s Equation

Therefore, the formula of Thomson’s Equation to calculate MPN/ 100ml is given as under:

2.Membrane Filter Technique

So, Nutrient added – M Endo Medium

Subsequently, Coliform colonies are counted after 20-24 hours of incubation.

3.Coliform Index

However, It is defined as reciprocal of smallest quantity of sample which gives positive B-coli test.

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