活性炭对氡吸附性能的影响因素研究

为了防止室内空气氡危害人体健康，采用被动式活性炭盒法，利用带铅室的低本底NaI (Tl)闪烁探测器测量活性炭样品的γ能谱总净计数，分别研究活性炭的吸附时间、干燥性、用量和放置位置对氡吸附量的影响，精确测量室内空气中的氡浓度。结果表明，最佳吸附时间为3 d或4 d；干燥的活性炭对氡的吸附能力强，前3 d，烘干活性炭的吸附量大于未烘干活性炭，最终两者吸附量相当；当氡在活性炭中的渗透深度小于活性炭的装填深度时，不同用量的活性炭对氡的吸附量相当，随着渗透深度增大，活性炭用量多的吸附量大；在氡浓度不均匀的密闭室内，活性炭放置位置对氡的吸附量无影响。综上所述，采用活性炭盒法测量室内空气氡浓度，应采用烘干、适量的活性炭，吸附时间为3 d或4 d，且不需考虑活性炭在室内的放置位置。

Influencing Factors of the Carbon Adsorption Properties of Radon

In order to prevent the indoor radon from being harmful to human health, it is necessary to accurately measure the indoor air radon concentration. Among them, the activated carbon box is one of the commonly used methods, but its accurate measurement is affected by many factors. To facilitate the accurate measurement of indoor air radon concentration, the passive activated carbon box method was used, and the γ-ray spectrum total counts of activated carbon samples with different conditions were measured by using a low background NaI(Tl) scintillation detector with lead chamber. The effects of adsorption time, dryness, dosage and position of the activated carbon on the radon adsorption capacity of activated carbon were investigated. The experimental results showed that the adsorption time was not as long as possible, the adsorption time was chosen for 3 days or 4 days for the best. The adsorbing capacity of radon was strong for the dry activated carbon, so in the first 3 days, the adsorbing capacity of radon was greater for the drying carbon than that for not-drying, and then with the adsorption time increasing, the water content for the dry activated carbon increased, and finally a phenomenon occurred that the two were equal. In the first 3 days, the penetration depth for radon in the activated carbon was less than the filling depth for the activated carbon, so the adsorption of radon was equal for the three different amounts of the activated carbon. With the adsorption time increasing, the penetration depth continued to increase, and finally the greater the amount of the activated carbon, and the greater the adsorption capacity of radon. In the closed and the radon concentration uneven indoor, the position of the activated carbon had no effect on the adsorption capacity of radon. Therefore, if using the activated carbon box method to measure the indoor air radon concentration, the dry, amount of activated carbon, and 3 days or 4 days for adsorption time should be used, and the position of the activated carbon in the indoor ground position was not to be considered.