The biochemical oxygen demand is computed by __________
Three sinusoidal voltage sources of three phase generator are
The average temperature of sewage in India, is
Carbonates in water produce
The nitrate concentration in domestic water supplies, is generally limited to
Coliform bacteria in water is an indication of the presence of
Excessive fluoride in drinking water causes
When temporary hard water is boiled, one of the substances formed is
Permanent Hardness of water can be removed by adding
An addition of small dose of chlorine gas to filtered water is known as
What is fourth step of raw water treatment