Blackbutterfly22

You cannot. It's on here forever. Though, you can request a moderator to permanently ban you.

Members can't delete accounts and they don't get banned upon request. Just don't use the account if you don't want it. But you may want to check your notification options and make sure that you aren't receiving any emails for comments, PMs, and other stuff if you aren't going to be active, just to save yourself that frustration.