Purifying water by boiling it sounds simple, but start-up firm knows it’s hard

When describing new technologies to lay people, similes are your friend. “This is like boiling water in a pot, but we’re doing it with a very efficient pot,” said Bill Zebuhr of Nashua, explaining the water- treatment system being developed by his latest company, Aquaback. OK, that makes sense – except that, like most similes, it misleads as much as it guides. I, for example, do not own any pots enclosed in giant Thermos jugs that have compression motors that spin at 42,000 rpm and heat water that is spread into thousandth-of-an-inch-thick films. Aquaback’s unit has all that and more, at least in theory. The 10-person firm is trying to develop a portable (26-pound), quiet, relatively cheap (about $5,000), efficient water-treatment system that uses good old distillation, in which you boil dirty water and then condense the steam back into water, leaving impurities behind. It’s still a good year away from production, but the idea and development were good enough to win the sustainable technologies category in NASA Tech Briefs’ “Create the Future” design contest.