Reverse Osmosis and pH: Introducing S.A.N.S.
I`m told Reverse Osmosis process can reduce the pH level in water to below the range recommend by the WEPA, WHO and other Thai ministries.
How do water producers manage the pH?
The pH reduction typically happens as source water has some CO2 present which forms carbonic acid when impurities are removed via RO. (CO2 + H2O → H2CO3). The RO membrane does not remove the CO2 so it needs to be either neutralized or removed in another way. Since most source water in Isaan has CO2 present then yes the pH is lowered after RO treatment most all of these cases. Most of the water producers raise the pH to help neutralize by simply by injecting Soda Ash - Sodium Carbonate (Na2CO3) after the RO filtration. If your drinking water tastes a little "gritty" or you see little white particles, it may be possible the producer is using this injection process to meet the 6.5-8.5 pH range allowed by the Health Department.
At JD Beverage, we control the pH with a more natural method we developed called Staged Aeration Neutralizing System or (S.A.N.S.). The SANS system consists of oil free air compressors, air filters, UV-C light air treatment outside the storage tanks then air stones and diffusing tubing inside the tanks. The filtered/treated air bubbles break the surface tension allowing the CO2 to escape from the water thereby increasing to the desirable pH level.
This system works very well with the size of operation focusing on smaller sized bottles and a nominal quantity of the larger jugs. A facility only refilling the large 18.9 and 20 liter jugs would need to increase the air influx and time of diffusing exponentially to keep the pH level within the accepted range. Ask your current water provider how they manage pH in their water.
NOTE: JD Beverage have been working with an official in the Health Department following his suggested theory to design and implement air bubbles to increase pH after RO since back in 2017. The official quickly invited JDB to present the S.A.N.S. system at the next Annual Food and Drug Drinking Water Symposium in Nongkhai once he saw the initial results. We have since tripled the aeration capacity in our system ensuring a near balanced pH throughout the entire day.
We will proudly share this knowledge to the other producers in order to raise the water quality in our community in the symposium setting as well as online here.