摘要
我国西南岩溶区表层风化沉积的红黏土是地下水污染的天然防渗材料之一。近年来,云南大量水电铝项目的实施对地下水造成极大的氟化物污染风险。因此,研究氟在红黏土中的运移机制对于岩溶区水电铝项目危废渣库的安全运营及地下水污染防治具有重要的生产实际意义。以云南省岩溶区红黏土作为研究对象,通过室内柱试验研究初始含水率对非饱和红黏土中氟运移的影响机制。研究表明,红黏土的初始含水率控制着氟的出流和穿透的时间、弥散系数、阻滞系数以及氟的垂直分布特征。这些参数对西南岩溶区不同季节不同含水率的红黏土地区土壤和地下水氟污染风险管控提供重要的依据。
The transport mechanism of fluorine in unsaturated red clay obtained from the surface weathering of a typical karst aquifer in southwest China was studied by laboratory soil column test.The red clay samples with different initial water content were wetted by different water heads.The tracer transport test was then carried out using the configured high concentration sodium fluoride and sodium chloride solution.The infiltration characteristics of the unsaturated red clay,the breakthrough and transport characteristics as well as the dispersion coefficient and retardation coefficient of fluorine in the unsaturated red clay were tested and calculated.Besides,the vertical distribution characteristics of fluorine were also analyzed by the concentration of different positions in the soil columns with different water contents.The outflow time and breakthrough time of fluorine increase with decreasing of the initial water content of red clay,while the breakthrough transport time is reversed.The fine particles in the soil column migrate and gather to the lower layer due to the vertical transport of fine particles in the flow process,which leads to the decrease of the permeability coefficient in the lower layer and thus increases the outflow and breakthrough time of fluorine.The dispersion coefficient of fluorine in the unsaturated red clay increases with the increase of the initial water content,while the retardation coefficient decreases with increasing the initial water content.The peak concentration width of fluorine increases with the increase of the initial water content since the diffusion coefficient of fluorine in the test red clay column increases with the increase of the initial water content.With the increase of the initial water content,the diffusion coefficient increases,leading to the increase of the peak width.
作者
强毅
李勇
邱仁敏
覃荣高
吕许朋
范良军
QIANG Yi;Li Yong;QIU Ren-min;QIN Rong-gao;LÜ Xu-peng;FAN Liang-jun(School of Land and Resources Engineering,Kunming University of Science and Technology,Kunming 650031,China;Yunnan Huber Environmental Technology Co.,Ltd.,Kunming 650228,China;Yunnan Geological Survey Institute,Kunming 650216,China;Southwest Nonferrous Kunming Survey and Design(Institute)Co.,Ltd.,Kunming 650217,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2021年第6期2827-2834,共8页
Journal of Safety and Environment
基金
国家自然科学基金项目(41867031)。
关键词
环境学
氟
初始含水率
红黏土
弥散系数
阻滞系数
environmentalology
fluorine
initial moisture content
red clay
dispersion coefficient
retardation coefficient
