Mechnanical booster for RO?

[jsiegmund]

Hi guys,

I'm looking into buying a booster pump for my RO system. As known, RO systems produce quite some waste water, something I want to prevent for both the environment as well as my wallet. At the moment I'm collecting the waste water in the bath tub and using it for a bath (mixing in hot water). So I'm not wasting water in that sense at the moment, but sometimes it is a bit inconvenient.

Now I ran into an interesting option, mechanical permeat pumps which reuse the waste water flow to build pressure increasing the effectiveness of the RO. The advertisement are very mixed, some say they produce 4 liters of waste for every liter of RO (which my RO unit already does when it's warm enough). Others claim they go up to 1:1, which I doubt.

Examples:
http://www.ebay.co.uk/itm/Permeate-...=UK_HGKitchen_SmallApp_RL&hash=item2346324cf2
http://www.ebay.de/itm/Permeat-Pump...s_Garten_Kochen_Geniessen&hash=item2329872fd1

So I was wondering if anyone has any experience with these units compared with a normal electrical booster pump. My assumption is that the electrical one will be better in all cases, but obviously requires electricity which is again bad for the environment and wallet (not as bad as dumping waste water btw). So if the mechnical one comes close (say 1:2), it might be the better option.

 

[Mr. Teapot]

This caught my interest, but after a quick google, it appears only useful if you're producing your water into a pressurised container (like the under-sink drinking water installations). If the water is being collected in a jerry can there won't be any pressure on the collection side to drive the mechanics in the pump.

I'm sure someone else on the forum is a lot more knowledgeable on the subject and let us both know a bit more info (or if my google search was correct)

 

[ian_m]

This looks like the second item and how it works.
http://www.purewaterproducts.com/articles/how-permeate-pumps-work

 

[jsiegmund]

Hmmm, interesting. So without that pressure it would not do much good, too bad. Going to order a booster pump then, thanks.

I also thought of another option: reusing the waste water to fill the reservoir of my toilet. Could work like this: have a jerrycan (preferably with a tap) positioned just above the reservoir (in my case: on the other side of the wall). Connect the normal toilet water supply (which would switch off as soon as the reservoir is full) to the RO unit. The waste water line goes in the reservoir, the RO water in the jerrycan. Connecting a second line from the top of the jerrycan to the reservoir would prevent the jerrycan from overflowing / getting too full. Would be a fun project to do, but I'm not sure if I use the toilet enough to get to the desired amount of RO water. So I'd need a booster pump anyway.

 

[jsiegmund]

Got my booster and gave it a test run today; performance is much better now. Now working on a DIY solution to warm up the intake line as the tap water around here is freezing cold at the moment.