Costs of getting rid of minerals from water

[7058]

Please let me know if it is possible to use the reject water from reverse osmosis (contains 4 times more minerals than normal potable water) and get process water (I assume something like distilled water) with 0% minerals.

How much would it cost to erect one plant capable of producing 240m3/day( 912gal/day).

How much would be production costs per gallon?

Dragan Andrejevic

Civ. Eng.

Tel: 604 985 6488 ext.256

 

[gr2vessels]

This is the size of a serious desalination plant, minimum cost of US$1bln, major disposal issues with the residue salts, size of a medium refinery, WOW!
Sorry, I got no idea how much would your gallon of distilate cost, depends on too many details.
cheers,
gr2vessels

 

[7058]

Dear gr2vessels and others,
Please take note that 240m3 is equal to 63360 gallons(US).
So the flow is 10m3/hour or 2.78 l/s or 44gpm.
I do not have any experience with reject water but I had a desalination plant in one 20 foot container and the capacity was 200m3 per day. How close are these two operations? Should there be a huge price difference?
Thank you and have a nice day.
Dragan

 

[gr2vessels]

Hi Dragan,
I rushed in with my comment, without checking the figures, you just did. I will come back with details for your plant shortly.
gr2vessels

 

[Unotec]

Cost is a very sensitive topic, I think, as it is tied to your location and labour/shop/material costs.
You should scope out the type of process you would like to use and then try to quantify the costs.

 

[bimr]

Reject from reverse osmosis reject is sometimes used for applications where lesser quality water is acceptable. A common application for reject water is cooling tower makeup.

If you have RO reject water with such high salt content that it is not acceptable for any water use, you should look into an evaporation process such as a brine concentrator. The evaporation process uses heat, waste heat, or electricity to concentrate the RO reject to a brine stream. Distilled water is produced as a byproduct.

You might be better off posting on the water forum.

 

[shahyar]

I am assuming you are using potable water (TDS max 500 mg/L) as feed for a one-stage brackish water RO (Recovery 75%). So, TDS of reject would be around 2000 mg/L. This TDS is not suitable for seawater RO or evaporation. You can add one more stage to your system to increase TDS of reject or using your reject for irrigation (specific plants) or watering cattles. Even this reject water is too "dilute" for injection in disposal wells.