含水率和粒度分形分布对铀尾矿库覆土层氡析出规律的影响研究  

Study on the influence of water content and particle size fractal distribution on radon exhalation in overburden soil layer of uranium tailings pond

作　　者：李向阳 刘晓璐 兰明 刘永 洪昌寿 汪弘 LI Xiang-yang;LIU Xiao-lu;LAN Ming;LIU Yong;HONG Chang-shou;WANG Hong(School of Environmental Protection and Safety Engineering,University of South China,Hengyang 421001,Hunan,China)

机构地区：[1]南华大学资源环境与安全工程学院,湖南衡阳421001

出　　处：《安全与环境学报》2021年第5期2209-2215,共7页Journal of Safety and Environment

摘　　要：为了探究覆土层含水率和粒度分形分布对氡析出规律的影响,制备不同粒度分维值和含水率的覆土试样进行氡析出试验。根据氡产生的机理,设计一套氡测量装置并用局部静态法以测定相应覆土层表面的氡析出率。采用相关分析方法研究覆土层氡析出规律与含水率和分维值的关系,构建氡析出率与含水率和分维值之间的分段线性函数。结果表明:在相同含水率、不同粒度分形分布时,氡析出率随分维值增大而减小,并且当分维值增加到一定值时,氡析出率开始趋于稳定;在相同粒度分形分布、不同含水率时,氡析出率先是随着含水率增大而增大,但是当含水率增加到一定值时,氡析出率却开始减小。氡析出率会受到含水率和粒度分形分布的综合影响。To explore the influence of water content and particle size fractal distribution of overburden soil on radon exhalation law,overburden soil samples with different particle size fractal dimensions and water contents were prepared for radon exhalation tests.According to the mechanism of radon generation,a set of radon measuring devices were designed and the radon exhalation rate of the corresponding overburden surface was measured by the local static method.The relationship between radon exhalation law and water content and fractal dimension of overburden was studied by correlation analysis,and the piecewise linear function between the radon exhalation rate and the water content and fractal dimension was constructed.Besides,the practicability of the regression formula is further verified.And the radon exhalation rate can be predicted under different water content and particle size fractal dimension values,which can be used for reference for the control of radon in overburden soil.The results show that at the same water content and different particle size fractal distribution,the radon exhalation rate decreases with increasing the fractal dimensionvalue.When the fractal dimension value increases to a certain value,the radon exhalation rate starts to be stable;At the same particle size fractal distribution and different water content,the radon exhalation rate first increases with the increase of water content.But when the water content increases to a certain value,the radon exhalation rate starts to decrease.The channels through which radon can diffuse and convect are reduced so that the radon extraction rate decreases with the increase of water content.There is a close linear relationship between radon exhalation rate and water content and fractal dimension value of overburden soil,and the correlation degree is high.The radon extraction rate can be affected by the combination of water content and particle size fractal distribution.

关 键 词：环境工程学 铀尾矿库 覆土层 含水率 分维值 氡析出率 

分 类 号：X34[环境科学与工程—环境工程]