摘要
为研究电渗迁移过程,进一步揭示电渗机理,基于杭州软土和自制电渗模型箱,分别采用铁和石墨电极开展室内电渗试验,监测重力排水、电渗排水以及电渗前后土壤中多种金属元素含量的变化;监测电流和排水量数据并据此计算电渗运移量。研究结果表明:在电渗排水过程中,钠离子和钾离子质量浓度比重力排水过程中的大得多,镁离子和钙离子质量浓度则比重力排水过程中的小得多,说明电渗法依赖双电层中低阶、小原子量反离子对水分的转移作用,土壤本身物理力学性质对电渗过程的影响主要通过双电层体现。电渗运移量对土壤含水率的敏感性与土壤类型密切相关,而对同一类土壤,其敏感性也可能会随着含水率范围的不同而呈现较大差异。在1.58V/cm的电势梯度下,杭州软土电渗处理后的最终含水率为35%左右,说明对于含水率小于35%的杭州软土,电渗法效果不明显,不推荐采用电渗法进行处理。
To study transport process of electro-osmosis and reveal electro-osmotic mechanism, laboratory electro-osmotic tests were conducted using a self-made model box and Hangzhou soft soil, with ferrum and graphite being the electrode materials. Mass concentrations of selected elements in the electro-osmotic drainage, gravity drainage as well as soil mass were monitored. Current and electro-osmotic dewatering were also monitored during the experiments to calculate electro-osmotic water transport per unit charge. The results show that mass concentrations of Na and K ions are much higher in electro-osmotic drainage than those in gravity drainage, while opposite results are obtained for Mgand Ca ions, which indicates that electro-osmosis technique has a dependency on the transferring of water by counters of low order and small atomic mass. Double layer constitutes the primary refection of the influence of soil physical and mechanical properties on electro-osmotic process. Sensitivity of the electro-osmotic water transport per unit charge to water content is closely related to the soil type, while for a given type of soil, this sensitivity may differ for varied range of water content. Under the potential of 1.58 V/cm, the ultimate water content of the deposed Hangzhou soft soil is 35%, indicating that the electro-osmosis technique is ineffective for Hangzhou clay with water content below 35%. It is thus not recommended to adopt the above technique to dispose Hangzhou clay with water content lower than 35%.
出处
《中南大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2018年第2期448-453,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(41427802
41572299
51478425
41602308
51708507)
浙江省自然科学基金资助项目(LQ17E090001
LZ13D020001
LQ13D020001)
教育部新世纪优秀人才支持计划项目(NCET-11-1080)
浙江省"新世纪151人才工程"资助项目(12-1-076)
浙江省交通规划设计研究院资助项目(2013W03)
软弱土与环境土工教育部重点实验室(浙江大学)开放基金资助项目(2016P01)
浙江科技学院人才建设经费资助项目(F701104F05)~~
关键词
杭州软土
重力排水
电渗排水
离子迁移
电渗运移量
含水率
Hangzhou soft soil
gravity drainage
electro-osmotic drainage
ion migration
electro-osmotic water transport per unit charge
water content