粘性土膜效应的实验研究  

EXPERIMENTAL STUDIES ON THE MEMBRANE BEHAVIOR OF THE COHESIVE SOIL

作　　者：左文喆[1] 徐叶净[1] 王英[1] 李明彦[1,2] 

机构地区：[1]河北联合大学,唐山063009 [2]河北钢铁集团矿业有限公司,唐山063009

出　　处：《离子交换与吸附》2013年第6期551-560,共10页Ion Exchange and Adsorption

基　　金：河北省自然科学基金(D2011209071);资助实验室:河北省矿业开发与安全技术实验室

摘　　要：通过反渗透实验验证了一组天然粘性土的膜效应和滤盐作用。土样采自滦河冲积扇30米深处的弱透水层,测试了原状土样的粒度、孔隙及粘土矿物含量。按原状土样的天然孔隙比装填土柱,饱和后用盐水进行定水头渗透。监测结果显示,入渗溶液不断浓缩,渗透流量减小。实验结束时,出流溶液中Cl-的浓度与入渗溶液的比值达1.1,Na+浓度增长明显低于Cl-。理论计算的入渗溶液Cl-浓度与实测浓度相近。入渗溶液的浓缩及粘土层表面的浓差极化现象表明粘性土具有一定的膜性能。粘土膜的效率系数σ与浓度呈负相关,与土体的固结程度呈正相关,与土体的离子交换吸附能力呈正相关。天然粘性土虽具膜性能,可使高压力一侧溶液浓缩,但并不能起到反渗透膜完全截留盐分的作用。A series of hyperfiltration experiments were conducted to investigate clay membrane behavior and filter salt effect about natural cohesive soil. Soil samples were collected from 30m deep aquitard of Luanhe River alluvial fan, and particle composition, pore characteristics and clay mineral content of the undisturbed soil sample were tested. Soil columns were backfilled according to the natural porosity ratio of the undisturbed soil samples. After saturation, the constant head penetration experiments were conducted with brine. Monitoring results showed that infiltration solution continuously enriched seepage discharge constantly decreased. At the end of the experiments, the ratio of the CI concentration of the outflow liquid and of the inflow solution was 1.1, and in addition concentration growth of Na^＋ was significantly lower than that of Cl^-. The Cl^- concentration of infiltration solution by theoretically calculated was close to the measured concentration at the state of the steady flow. The experimental results of the infiltration solution concentration and the concentration polarization phenomenon of the clay layer surface indicated that the clay had certain membrane properties. The efficiency coefficient a of clay membrane was negatively correlated with concentration of ions and degree of soil consolidation, and was positively with degree of soil consolidation degree and the ion exchange adsorption ability of the soil. Although the natural cohesive soil had membrane properties and could concentrate the solution at the side of high pressure, it couldn＇t play a role of restricting completely salt as reverse osmosis membrane.

关 键 词：膜性能 粘性土 反渗透实验 

分 类 号：P641[天文地球—地质矿产勘探]