Topic: Water Purification.
Why is alum added to water?
Because water does not like to be alone.
It wants somebody's company.
No.
Alum is added to purify water.
Alum is aluminium sulfate.
It acts as a coagulant.
A coagulant attracts and binds with extremely fine and small particles to form a large particle.
I won't use it.
But why?
Because it will attract all small insects and make a large insect.
You are just unbelievable.
When a solution of alum is added to impure water.
It attracts and binds with contaminants and fine suspended particles of mud, dirt, etc.
To form large particles.
Being large, these particles can be removed by filtration, or when they settle down due to gravity.
They can be removed through decantation, giving us pure water.