Too high sodium content in well water

Asked October 23, 2016, 7:12 AM EDT

In my region there is no water available, I drilled a well, however the salt content is too high, above 4000 mg per liter. RO process is very expensive to use. Is there any chemical process that be used to reduce the sodium content to enable the water to be drinkable? This water is located in a very low income area in Brazil. And I am try to produce drinkable water to distribute to the low income people that is suffering due a six-years drought in that region. Thank you for the help.

Outside United States drinking water water quality water water treatment

1 Response

There are only three reliable methods for removing very soluble sodium salts from water. These methods include forcing water through semi-permeable membranes (reverse osmosis or R.O.) to filter out salts, distillation followed by condensation to leave salts behind, and ion exchange (deionization) to replace the cations and anions of the sodium salt with hydrogen and hydroxide ions. The first two methods have the greatest energy requirement to either generate high pressure to force water through a small-pore membrane or generate the heat to evaporate water and then collect the steam. Both evaporation and the ion exchange process are not generally recommended for treating large volumes of water. However, if costs for energy needs is a primary issue, and you are providing only water for drinking, with untreated water containing the 4000 mg per liter of salts, used for cleaning and other purposes, the use of ion exchange may suit your needs--depending on volume of water needed. Bottled water is also an alternative. You must keep in mind that ion exchange does not remove bacteria from water and that the process must be monitored because the exchange resin in the filter units for this process must be periodically recharged to keep functioning properly. There are also some concerns for long-term health effects from drinking water with most of the minerals removed (This applies to all three methods.). Some medical professional recommend adding small levels of calcium and magnesium salts to drinking water treated by R.O., distillation or deionization if adequate levels of these minerals are not received in the diet. I recommend that you touch base with NSF International about the availability of products to fit your needs. Their URL is www.nsf.org.