Determination of radon partitioning between groundwater and atmosphere by liquid scintillation counter

A simple method for the determination of the air?Cwater partition coefficient (K_air/water) of radon (Rn-222) was studied using a liquid scintillation counter. In the present work, the radon activity of groundwater phase in a closed container was measured and used to calculate the partition coefficient instead of the radon activity of gaseous phase in other works. The partition coefficient was determined for four groundwater samples by using a modified equilibrium partition coefficient in closed system method. The effect of temperature on the partition coefficient was investigated at 0, 10, 20 and 30?°C. Within the temperature range, the partition coefficients were 1.72?C2.03, 2.11?C2.28, 2.78?C3.92 and 4.93?C5.61 at 0, 10, 20, and 30?°C, respectively. It was found that the effect of temperature on the air?Cwater partition coefficient of groundwater radon was agreed well with literature values.