The conditioning of natural waters for drinking by fluorides

Performance of nanofiltration membrane OPMN-P (Russia) and low-pressure reverse osmosis membranes OPAM-KN (Russia), ESPA-1 (USA) and TFC-75 (USA) during the purification of fluorine-containing waters was studied. Working characteristics of the used membranes were described, depending on the level of the permeate water selection, while treating solutions, which contain maximal allowable amount of the flourine-ions. The threshold concentration of fluorine-ions in natural waters (Ukraine) is determined, when it is expedient to apply these membranes to remove the excessive amount of fluorides and to preserve their physiological norm in the treated water.