Obtaining deuterium directly from water I know that there is 2:6400 deuterium and hydrogen molecules respectively in water.

When electrolysis is done, hydrogen and oxygen will be obtained. The hydrogen obtained should contain small amounts of d2 and t2.

Is there a way to separate it by diffusion or effusion (or any other way)?
Deuterium is already obtained by electrolysis of water. Deuterium is a little less reactive than Hydrogen, So when we repeatedly electrolyze water, we get heavy water. Then we can obtain deuterium from that.