Daryo Sep 11, 2020:

@ Asker when you say

"Closing mechanism in the bottom of the sink."

would that mean that you can manually close it and open it as needed? (to fill the basin with water or drain it)

"un syphon / a P-trap, also known as the U-bend" doesn't sound like a good candidate - it's NOT really "closing" anything, it just acts as a barrier preventing odours from the drain getting into the kithen most of the time / only in "normal" operation. Most often it can't even stop rats or creepy-crawlies ...