Hi Albino
Maybe you can "empty" your account. It's not exactly deletion, but it's something...

In the issue https://github.com/e14n/pump.io/issues/347 some ways to perform this workaround are explained: unfollow the people you follow, delete your posts, unfavorite your favorites, and change your account name to "Account moved" or "account deleted" or something like that.

Hope this helps.