| 赤泥渗滤液对钠基膨润土黏土衬垫的渗透机理分析 |
| |
| 引用本文： | 李芹,廖才能,廖明旭,彭道平,黄涛.赤泥渗滤液对钠基膨润土黏土衬垫的渗透机理分析[J].环境工程,2021,39(1):148-153. |
| |
| 作者姓名： | 李芹 廖才能 廖明旭 彭道平 黄涛 |
| |
| 作者单位： | 西南交通大学地球科学与环境工程学院,成都611756 |
| |
| 基金项目： | 四川省科技计划项目（2019YJ0244）；软弱土与环境土工教育部重点实验室（浙江大学）开放基金（2019P04）。 |
| |
| 摘 要： | 赤泥渗滤液的高离子强度可以抑制蒙脱石的膨胀，从而导致钠基膨润土黏土衬垫（GCL）的渗透性过强，并无法用作赤泥处理设施中的防渗衬层。通过2种钠基膨润土黏土衬垫与2种赤泥渗滤液的渗透过程，研究强碱性赤泥渗滤液与钠基膨润土黏土衬垫的渗透机理。结果表明:天然钠基膨润土（Na-GCL）和人工钠化钠基膨润土（Ar-GCL）的渗透系数与赤泥渗滤液的离子强度密切相关，随着离子强度的增加，渗透系数呈递进式系统性增大，对高离子强度的山东赤泥渗滤液的渗透系数最大，分别为7.8×10-7，3.2×10-7 m/s。且两者的渗透系数与膨胀指数呈正相关，SEM扫描的微观结构分析发现，膨润土的膨胀机理控制着其渗透作用。高离子强度会使膨润土中的蒙脱石矿物层间发生渗透性膨胀，并吸收大量的水分，减小孔隙度的同时改变流体的流动路径，从而导致渗透系数提高。该结果可为赤泥堆场底部防渗设计提供更为可靠的理论参考，有效降低我国赤泥堆场渗滤液污染风险。
|
| 关 键 词： | 钠基膨润土黏土衬垫 赤泥渗滤液 渗透系数 膨胀指数 渗透机理 |
| 收稿时间： | 2019-12-12 |
MECHANISMS CONTROLLING HYDRAULIC CONDUCTIVITY OF BENTONITE CLAY LINERS WITH BAUXITE LIQUOR |
| |
| Affiliation: | Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China |
| |
| Abstract: | The high ionic strength of bauxite liquor could suppress swelling of montmorillonite, which results in sodium bentonite clay liner (GCL) that was too permeable to be used as an impermeable liner in red mud treatment facilities. The mechanism controlling of strongly alkaline bauxite liquor and sodium bentonite clay liner was investigated through the infiltration process of sodium bentonite clay liner and two types of bauxite liquor. The results showed that hydraulic conductivity of natural sodium bentonite (Na-GCL) and artificial sodium bentonite (Ar-GCL) was closely related to ionic strength of bauxite liquor. As ionic strength increased, hydraulic conductivity systematically increased. Hydraulic conductivity of Shandong bauxite liquor with high ionic strength was the largest, 7.8×10-7 and 3.2×10-7 m/s, respectively. Hydraulic conductivity was positively related to swelling index. Through the analysis of the microstructure diagram of SEM scanning, swelling mechanism of bentonite controlled its hydraulic conductivity. High ionic strength caused permeable expansion of bentonite mineral layer, and absorbed a large amount of water, which reduced the porosity and changed the flow path of the fluid, resulting in an increase of hydraulic conductivity. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《环境工程》浏览原始摘要信息 |
|
点击此处可从《环境工程》下载全文 |
|
