Talk:RO Desalination

Does anyone know if this makes sense? "The pump supplies the pressure needed to push water through the membrane," In an RO process, water isn't really 'pushed' across the membrane. The pressure that is applied to the feed water is used to offset the osmotic potential across the membrane that exists when there is a semi permeable membrane between fresh water and a concenctrate. "Pushing water" is used in microfiltration processes where the water is literally pushed through a filter and thereby cleaned.

This page needs assistance. Please feel free to help. I've been dribbling in bits an pieces now and then, but any assistance is welcome. I'm still playing with the pretreatment and have yet to modify the original authors portion. FOK SD OA 21:12, 20 September 2006 (UTC)

Can't answer the above - however - the page also states that energy consumption is low using RO - which contradicts what is stated on the Desalination-page (I find the info on the other page more plausible - or maybe just so in a cogeneration plant). Poul Østergaard

@FOK SD OA - It's informal language, but it makes sense; water molecules move from the source brine across the RO membrane to emerge as the desalinated water stream. You are correct that the pressure applied to the feedwater offsets the osmotic pressure difference between the feedwater and purified water on the other side; however, in order to generate clean water, the pressure must exceed the osmotic pressure difference. If the feed pressure exactly equaled the osmotic pressure, the system would be at equilibrium and no net flux across the membrane would occur. susato 18:14, 9 November 2006 (UTC)