Reverse osmosis is NOT dependent on the way it is forced through a semipermeable membrane, just that it is. Water pressure, steam, electric pump, water fall, mechanical pump, etc, it does not matter. It is really quite simple.
Just force it through and it works and is filtered. The semipermeable membrane is all that matters. bad stuff on the one side, good stuff on the other. Usually it does not as long as the “good” H2O atoms are one size and go through the “bad” atoms (iron, chlorine, body waste, etc are bigger and do not.
Water powered or steam the force is not what matters. My brother has one on his faucet and it is totally water powered. Just water pressure does it. But it wastes a bunch of water, converting it to steam just makes it more efficient.
Thanks for the correction, I was working off of very dated knowledge. The company I used to work for had a "dirty water" division and they shared a lab building with the hydraulics group (us). They were working on a portable water treatment plant for the air force. The first contract phase was for gray water, the second phase added sanitary waste. At the time, almost forty years ago, they used aerobic digestion, flocculation & settling, with a RO unit as a final filter for phase two. As I recall it used electrophoresis to move the water through the membrane, hence my assertion that RO involved electric current.
Since we shared the building we all tried the finished product. It tasted flat like distilled water and we recommended that it be aerated before use.
One question for you, since all filters have a pressure drop across the media, what differentiates a RO unit from say a millapore filter with sub-micronic media? Regards,
GtG