Android isn't Windows.
In Windows, "deleting" a file simply moves it to another folder named "Recycle Bin". It doesn't actually delete the file. Emptying the Recycle Bin actually deletes the files.
In Android, deleting a file deletes it. There's no "trash" to "empty".
About the only place that's not true is in an email program. If you have a trash folder in there, deleting the files in it is the same as "emptying" it.