Think of it in another way. If you manage to sterilize the bandaid, using boiling water, or nuking it in a microwave etc., you would be using energy to do so, which would negate any green saving. If you didn't sterilise it sufficiently then you are looking at possible infection, meaning:
📍 Visit to the doctor or hospital (travel by car perhaps; petrol)
📍Other dressings (more expense and energy used in production)
📍 Use of medications (usually wrapped in non recyclable materials), that are usually sourced from organisations with high manufacturing costs.
It would seem using another, fresh and sterile bandaid would be the more "green" way of treating a wound. I have gone one better though; cut open a portion of aloe leaf lengthwise, place on wound and used a little sticky tape to secure. Guess one could have tied it on with a little recycled hemp twine though! 🖖