Purge : rid (someone or something) of an unwanted quality, condition, or feeling.
Promote : support or actively encourage (a cause, venture, etc.); further the progress of.
Increase : become or make greater in size, amount, or degree.
Rehabilitate : restore (someone) to health or normal life by training and therapy after imprisonment, addiction, or illness.
Encourage : give support, confidence, or hope to (someone).
Antonym of
Purge is
Rehabilitate