Dissolution And Exhalation Behavior Of Radon In Radon-containing Radioactive Water In The Field Of Uranium And Mining

In recent years,nuclear power construction has greatly promoted the development of China's uranium mining industry.Based on the requirements of environmental protection and health,a lot of fruitful research for radon pollution has been carried out in the field of uranium mining and metallurgy.However,there is little research on the dissolution and exhalation behavior of radon in radioactive water.For this reason,the mathematical model of radon transport in radioactive water was first established,and the numerical simulation was carried out.The relationship between the radon effluent rate at the bottom of the water body,the diffusion coefficient of radon in the water body,the radon transport rate,and radon concentration are studied.Then,the experimental device of the radon solubility coefficient,the radon exhalation rate and the radon transmission rate at the gas and liquid interface were designed and fabricated.The changes of radon solubility coefficient under different salinity,temperature and pH conditions in water and the radon exhalation rate and radon transport rate at different air velocity were studied.Finally,the theoretical values in the literature are compared with the experimental measurements,and the accuracy of the experimental results is verified.Research results are as follows:(1)One dimensional differential equation for radon migration in the water containing radon was established using radon seepage-diffusion migration theory and the formula for calculating the concentration of radon in water and the radon exhalation rate at the water surface were derived.In addition,the variation of radon concentration in water and radon exhalation rate at the surface of water were studied when parameter changes such as radon exhalation rate from the emanation medium at the bottom of water body,radon transfer rate,radon diffusion coefficient in water and the depth of the water.The results showed that:when the other parameters remain unchanged,1)The concentration of radon at the same depth of water and radon exhalation rate on water surface increases with the increases of radon exhalation rate from the emanation medium at the bottom of water body;2)The concentration of radon at the same depth of water decreases and radon exhalation rate on water surface increases with the increases of radon transfer rate;Furthermore,when radon transfer rate is larger than 1×10-6m/s,the change of radon exhalation rate on water surface is not obvious with the change of radon transfer rate;3)The concentration of radon at the same depth of water and radon exhalation rate on water surface increases with the increases of radon diffusion coefficient in water;4)The concentration of radon in water that close to the surface and radon exhalation rate on water surface decreases with the increases of water depth.(2)The experiment of measuring the solubility coefficient of radon under different salinity,temperature and pH in water was carried out by using the xperimental device for radon solubility coefficient of water.The results show that the solubility coefficient of radon in water decreases with the increase of water temperature and salinity.(3)An experimental setup was designed and fabricated for the radon exhalation rate at the sample surface and the radon transfer rate at the gas-liquid interface.The radon removal rate of the ore surface increases with the increase of the wind speed of the ore particles,and decreases with the increase of the water level in the ore.In addition,the gas-liquid interface radon transmission rate increases with the wind speed increases.