The original problem is the research of low energy consuming process to take away D2O from drinking water. Reading the Q&As on this post, particularly the answer provided by @DjohnM, I would like to understand if the mentioned considerations change with temperature. For instance, taking the beaker mentioned by @DjohnM close to 0°C, let's say to 0.01°C, will the gravitational effects prevail enough on the liquid kinetic taking the D2O at the bottom of the container in a proper time scale? Here the pertinent part of @DjohnM answer:
there are many factors that could lead to temporary non-uniform distributions of deuterium atoms in the majority of "normal" hydrogen atoms in sea-water. So, if one were to pour a beaker of D2O carefully and slowly into a beaker of normal water, the heavy water would be found concentrated at the bottom of the beaker.
However, the OP's question seems to me to be: If we mix the stratified beaker above, will the higher concentration of deuterium at the bottom of the beaker be restored?
In my opinion, the answer is yes, with a serious reservation. The concentration would depend on how large the difference in gravitational potential energy is, compared to the basic kinetic energy of the atoms in the solution. My thought is: not much. How often do you find a layer of alcohol at the top of an long-undisturbed bottle of beer?
In a similar vein, leaking chlorine (from, say a tank car) does concentrate in lower areas. However, a gymnasium full of thoroughly mixed chlorine-contaminated air will never have a centimeters-thick layer of poison at floor level. The gas molecules are travelling at speeds of the order of the speed of sound. Just compare 12v2 with gh.
