Concept:

Taste and odour in water is determined by diluting the raw water sample up to an extent taste and odour in water is hardly detectable. Intensity of taste and odour in water is expressed in terms of unit called Threshold Odour Number (TON), which signifies the dilution ratio at which taste and odour is hardly detectable. It is measured in the apparatus called Osmoscope.

Note:

1. Acceptable limit: 1 TON.

2.Cause of Rejection Limit: 3 TON.

3.Sources for taste and odour in water: Inorganic salts like Na, Ca, Mg etc, Organic dissolved impurities, dissolved gases like H2S, CO2.