You can centrifuge it. Heavier molecules move closer to the bottom. Repeat until you reach the desired purity.
You need shitloads of ordinary water to extract a liter of heavy water. And I'd be surprised if there's any superheavy water in that, because tritium radioactively decays.
Fun fact: Heavy water is slightly toxic to humans. If you only drank heavy water, you'd die as it shifts the chemical reactions in your body out of balance. A moderate amount is fine though.
You can centrifuge it. Heavier molecules move closer to the bottom. Repeat until you reach the desired purity.
You need shitloads of ordinary water to extract a liter of heavy water. And I'd be surprised if there's any superheavy water in that, because tritium radioactively decays.
Fun fact: Heavy water is slightly toxic to humans. If you only drank heavy water, you'd die as it shifts the chemical reactions in your body out of balance. A moderate amount is fine though.
Another fun fact - heavy water has a sweet taste.
How did someone ever figure this one out?
Probably by drinking it. As I said, it's only slightly toxic. Cody's Lab has done it on YouTube. 0.01% of the normal water you drink is heavy water.
There are a variety of ways to do it, but you'd want to be careful that you don't attract attention from your local nuclear regulatory agency.
https://en.wikipedia.org/wiki/Heavy_water#Production_methods