# Deuterium removal from water

What percentage of deuterium might be removed from water after a typical electrolysis procedure? From a post on this site I read that, "In the first stage, $\ce{NaOH}$ solution (initially $0.5\rm{M}$) is subject to electrolysis, until only $\frac{1}{32}$ of the original volume remains. This increased the original concentration of deuterium by a factor of $12$."

This seems to be, for the electrolyzed hydrogen, an approximate $38\%$ decrease from the original concentration. If we assume the original concentration was $150\rm{ppm}$ then after the first pass, we might expect to have $93\rm{ppm}$ in the deuterium reduced hydrogen. If my estimate is valid, may I expect that each successive pass would reduce the deuterium content by a similar percentage?

• Looks like so. Also, the procedure is likely optimized for getting deuterium; if your goal is opposite, you might want to stop at an earlier point. – Ivan Neretin Mar 1 '16 at 6:06