repellent, repulsive
Repulsive is the stronger of the two words, implying physical recoiling rather than just a feeling of disgust:

• I was given some repulsive food which, by the end of the second day, I trained myself to eat —Brian Aldiss, 1991

• It's hard to imagine a more repellent group of people —Sunday Herald, 2000.

For repellent the spelling -ent is preferable to -ant for both the adjective and the noun.

Modern English usage. 2014.