physical characterstics of water

1. Turbidity 

when the large suspanded matter such as clay or silt and other muddy cloudy turbits are prresent in the water,it showas the turbityof water.

• turbity or raw water is measured by turbidity rod / turbidometer
• The standard unit of turbidity is mg/l or ppm 
• the unit of turbidity 1 mg silica divided by 1 litre of distilled water
• turbidity for drinking water is vary 5 to 10 units
• turbity in clear lake is about 25 units
• And for muddy lake is about 100 units

2. Colour

• The desolve organic matter from decay and inorganic matter such as coloured soil may impart to the colour to water.
• The excessive growth of algae and adequatic micro-organism also impart colour to the
• however the colour of water concidered objectionable from phychological point of view
• The colour or water from the health of view is not objectionable 
• But colour may spoil cloth being washed
• The standart unit of colour is1 mg platinum cobalt dessolved in one litre distilled water
• the maximum permissible colour for domestic supply is 20 ppm 
• for the public supply colour number on cobalt scale not exceed 20  and not lessthan 10 

3. Taste and Odour

• the dissolved orgenic matter and dissolved gasesimpart the taste and odour of the water
• dissolved gases such as H2S,CO2,O2,CH4...etc
• for the drinking purpose the water must not containany objectionable taste and odour
• for the public supply the water should be free from odour  and odour  number should be 1 and not exceed 3

4. Temprature

• for the potable water 10 degree celcius temprature highly desirable
• Temprature above 25 degree celcius concidered objectionable

5.specific conductivity

• specific conductivity of the water is the ability of water to conduct electricity
• pure water is poor conductor of electricity
• The specific conductivity is measured by potable ionic water tester called conductivity sensor
• onductivity is measured in (mhos)
• mhos = 1amp/1valt
• or 1mhos = 1seimen this unit is renamed by ISO
•  In clean water it range is (micro seimen/cm = 1*10^-6 seimen/cm)
• specific conductivity of water is increased with the increasing temprature so it's measured at 25 degree celcius (standatd temprature )
• to convert micro (seimen./cm) into ppm we will have to multiply by conductiity facotor
• conductivity factor vary from 0.54 to 0.96 and generrally it's taken 0.67