Simple:
* The purification of the water supply is essential for public health.
* The scientist conducted a purification experiment to isolate the desired compound.
Figurative:
* The artist's process of purification involved removing all unnecessary details, leaving only the essence of the subject.
* After a long and arduous journey, she felt a sense of purification, her soul cleansed of negativity.
Specific:
* The purification of the sewage water involved several stages of filtration and treatment.
* The purification of gold involves removing impurities through various chemical processes.
More Complex:
* The ancient ritual involved purification through fire and water, symbolizing the cleansing of the spirit.
* The purification of the air from harmful pollutants is a major environmental concern.
The best sentence for you will depend on the specific context you have in mind.