2006 Volume 55 Issue 11 Pages 679-686
High radon concentrations have been found in potable water originating from groundwater. Radon in potable water presents a possible health risk to humans. For the purpose of reducing the health risk due to radon in water, the following methods were investigated in order to remove radon from potable water: the use of softeners and purifiers, heating, aeration and leaving water standing in bottles. (1) Domestic softeners and purifiers : When grainy activated carbon is used as filtration material, the increase of radon removal ratio is certain, if for a short term, but the removal ratio is lowered with increase of water quantity to be treated. (2) Heating : The radon concentration in water decreased depending on the water temperature. Radon was almost completely removed when the water was thoroughly boiled. (3) Aeration : Radon was efficiently removed when water was aerated. The removal ratio of radon increased exponentially as the volume of aeration increased. (4) Leaving water standing in bottles : The concentration of radon in bottled water where the lid was not closed decreased gradually. The removal ratio of radon depended on the shape, depth of the bottle and the contact area between the water and air. The water-air interface was intensely disturbed by boiling, aeration, and bubbling, and these methods demonstrated an effective removal of radon.
