Filtering Pool Water for Emergency Drinking....

[Montu]

So just wondering, would a Reverse Osmosis system + the Deionization stage (if needed) render our pool water safe to drink?

I have solar panels that can provide power off the grid to power say a small submersible pump that can then push water through an RODI unit...I've assumed this would be safe for long term emergency drinking...but is it?

Discuss

 

[Richard320]

Reverse Osmosis produces essentially distilled water, so yes you could drink it.

 

[Montu]

Thanks! Just making sure I wasn't missing anything..

Do you think the DI stage is necessary to get the water down to 0 TDS or does just the R/O part do the trick?

 

[Richard320]

Thanks! Just making sure I wasn't missing anything..

Do you think the DI stage is necessary to get the water down to 0 TDS or does just the R/O part do the trick?

I haven't got a clue what you just asked.

 

[Montu]

I haven't got a clue what you just asked.

Reverse Osmosis systems don't filter everything out because we want the trace minerals our body uses, there is an option to add an additional stage which is a DeIonization Resign that will strip the water of the last trace elements..this is used to get the water even more pure for use in fish tanks for instance.

I was just wondering if any chemicals or containment's we have in the pool are small enough to get by the normal R/O filters and thus would require the use of the last DeIonization stage.

 

[JoyfulNoise]

It all depends on what your overall TDS is, many RO membranes have very specific limits on TDS and calcium hardness. Normally you want to demineralize (remove calcium) the input stream of an RO filter. So one would typically want to run a salt based water softener on the input side of the RO filter to get CH low as calcium scaling will destroy the membrane. You'd also need to dechlorinate the water using an active charcoal pre-filter as well as a fine particulate trap down to 1 micron. Then, the RO filter will remove all the other minerals, ions and organics. If you did not have a water softener, then one can inject phosphonate calcium sequestrants (HEDP) along with the input water to bind up the excess calcium and then all of the calcium and phosphonates would go out the waste stream. One final problem is pressure - most RO filters need high pressure to operate with any decent efficiency (low waste fraction). A sump pump produces very little pressure and so you would be sending most of the water to waste. Algae in the input stream would also be a huge problem as well.

Simply boiling the water and using a steam reforming column will get rid of most of the chemicals in the pool water and render it drinkable.

 

[Montu]

It all depends on what your overall TDS is, many RO membranes have very specific limits on TDS and calcium hardness. Normally you want to demineralize (remove calcium) the input stream of an RO filter. So one would typically want to run a salt based water softener on the input side of the RO filter to get CH low as calcium scaling will destroy the membrane. You'd also need to dechlorinate the water using an active charcoal pre-filter as well as a fine particulate trap down to 1 micron. Then, the RO filter will remove all the other minerals, ions and organics. If you did not have a water softener, then one can inject phosphonate calcium sequestrants (HEDP) along with the input water to bind up the excess calcium and then all of the calcium and phosphonates would go out the waste stream. One final problem is pressure - most RO filters need high pressure to operate with any decent efficiency (low waste fraction). A sump pump produces very little pressure and so you would be sending most of the water to waste. Algae in the input stream would also be a huge problem as well.

Simply boiling the water and using a steam reforming column will get rid of most of the chemicals in the pool water and render it drinkable.

Nice! Thanks

I do have a softener but then it just becomes quite complex... low efficiency wouldn't be much of a concern given the thousands of gallons at my disposal (my pool + neighboring pools)

 

[JoyfulNoise]

The biggest killer would be calcium. Seeing as you're up in Phoenix area, your pool water is likely quite high in CH. Once scaling starts inside the RO membrane, your system will simply stop functioning and all of the water will go to waste. You have to control the input TDS and CH or else your scheme will simply not work, even if you could up the pump pressure.

This one reason why "whole house" RO makes no sense and is very costly - you have to control so many variables that the system becomes horribly complex and expensive to run and maintain.

This would be a much simpler solution in your area -

How to Build a Solar-Powered Water Purifier - dummies

How To Build A Solar-Powered Still To Purify Drinking Water | Off The Grid News

These guys actually started with seawater as the input source -

Solar-powered water purifier may be three times as efficient as current models

 

[Montu]

Great! I will be sure to share this info as I know my father was interested in this as well as some guys on another forum i'm on (I'll quote and link of course)

 

[spoonman]

I would think that in a real emergency you could safely drink the pool water as-is provided that it was properly sanitized and the pH was reasonably in line.

Could someone else weigh in on this?

 

[dorgan]

You should NOT drink DI. Only the RO part is needed

 

[jblizzle]

I would think that in a real emergency you could safely drink the pool water as-is provided that it was properly sanitized and the pH was reasonably in line.

Could someone else weigh in on this?

There are many threads that discuss this in-depth. Bottom line there are some things in the water you do not want to be drinking like the stabilizer and borates if you've added them. The pool should be considered an absolute last ditch solution, without sombre kind of purification system.