Step-by-step explanation:
Water can be purified from through...
Filtration - This involves the use of filter paper to remove solid objects found in water.
Boiling - This involves keeping water at 100 deg celcius for a while through application of heat and this kills microorganisms in the water.
Addition of alum - Alum causes very fine and small particles that are suspending in water to stick together making them large enough to be removed through filtration.
Chemicals used in water treatment...
Chlorine - Chlorine is used to kill bacteria, viruses and other disease causing pathogens found in water
That's all I know...