Milky Water - Air / Water Separator

[esass13]

We're having problems with milky water and we think our well water has entrained air. Does anyone know a good way or reliable product to get the air out? There is some question as to whether it's air or carbon dioxide. Does anyone know an easy way to tell the difference?

thanks for the help

 

[bimr]

It is unlikely that you are dealing with "entrained" air.

If you want to remove dissolved gases, the least expensive approach is proabably a tray aerator:

http://www.usfilter.com/NR/rdonlyres/

90764F57-B7D4-4AF4-AF4F-981B41F6CC84/0/aerator_brochure.pdf

The dissolved gas will be either carbon dioxide, oxygen, methane, nitrogen, or hydrogen sulfide. An inexpensive pH test will tell you whether or not it is carbon dioxide, since carbon dioxide will lower the water pH to less than 6 units.

 

[orenda1168]

Essas13:

What leads you to believe that the "milky well water" is a result of entrained air (or CO2)? Upon standing, does the water clear, as it quickly will if in fact there is entrained air or other gas. If it is air/gas entrainment, this should not present a problem for potable use, though it may require deaeration for some industrial applications.

If the water does not clear with standing, something else is causing the milkiness, and will call for a complete analysis.

Orenda

 

[hydrae]

Check the bladder on your well pump pressure tank
a leaky bladder will loose its air into the water causing the milky color, when the air is gone from the tank, the pump will have very short cycle times damaging the pump, motor and plumbing
Hydrae

 

[sbush]

Membrane contactors work very well in municipal and industrial applications. The city of Flagstaff uses this method for several of their wells where dissolved air produces milky water. This method will also work for dissolved CO2 and other dissolved gases.

Membrane contactors are configured in a pressure vessel similar to a tube and shell heat exchanger. These vessels contain bundles of hollow-fiber type synthetic membrane made of specially designed hydrophobic materials that allow dissolved air and other gases to pass through to the dry side while retaining water on the wet side. In most cases, a slight vacuum is applied to the dry side; however, at Flagstaff no vacuum was necessary to remove dissolved air from the water. Unlike aerators (which also work for this application as Bimr has suggested), membrane contactors operate under pressure and do not require water storage and repumping.

Naturally-occurring CO2 in water (not to be confused with carbonated water) doesn't produce visible bubbles when viewed in a glass at atmospheric pressure. A low pH (less than 6.8) is another marker for the presence of CO2 in ground water, but not in every case.

Dissolved air can occur naturally underground or from leaks in above ground piping or pump seals. Hydropneumatic tanks with air cushion or bladder tanks that leak (as Hydrae points out) can also introduce air. When air is pressurized, it dissolves in water. When the source of pressure is relieved, dissolve air is released in the form of micro bubbles. This process is actually used to float flocculated solids in a water treatment process known as dissolved air floatation.

S. Bush

http://www.water-eg.com