西安建筑科技大学学报(自然科学版)

为探究无机盐溶液浓度、阳离子价态以及碱性对钠基膨润土膨胀特性的影响规律,采用不同浓度的KCl、CaCl2、MgCl2、AlCl3、K2SO4、K2CO3、KOH、NaCl和NaOH溶液替代蒸馏水对钠基膨润土进行自由膨胀率试验.研究发现:盐溶液中的K+、Mg2+和Al3+取代了抗衡离子Na+,且随阳离子价态增加,对Na+的置换率逐渐增大; 钠基膨润土的自由膨胀率随溶液浓度的增加而下降,并且其过程分为三个阶段,金属阳离子价态越大,在第一阶段对膨胀潜力的抑制效果越显著; 当溶液浓度大于0.25 mol/L时,K+对膨润土膨胀潜力的抑制效果更为显著; 在盐溶液呈弱碱性时,其中少量的OH-会促使土颗粒的分散作用; 当NaOH溶液浓度低于0.6 mol/L时,自由膨胀率主要受溶液浓度的影响,当NaOH溶液浓度高于0.6 mol/L时,自由膨胀率受到溶液浓度和高pH值双重作用的影响.

In order to investigate the influence of the concentration of inorganic salt solution, cation valence and alkalinity on the swelling characteristics of sodium bentonite, sodium bentonite is tested for free expansion rate using different concentrations of KCl, CaCl2, MgCl2, AlCl3, K2SO4, K2CO3, KOH, NaCl and NaOH solutions instead of distilled water. It was found that K+, Mg2+ and Al3+ in the salt solution replaced the counter ion Na+, and the replacement ratio of Na+ increased with the increase of cation valence. The free expansion rate of bentonite decreased with the increase of solution concentration, and the process is divided into three stages. The higher the valence of the metal cation, the inhibitory effect of the first stage on the expansion potential is more pronounced. When the concentration of solution is more than 0.25 mol/L, the effect of K+ on the swelling potential of sodium bentonite is more significant. When the salt solution is weakly alkaline, a small amount of OH- promotes the dispersion of the soil particles. When the concentration of NaOH solution is lower than 0.6 mol/L, the free expansion rate is mainly affected by the concentration of the solution. When the concentration of NaOH solution is higher than 0.6 mol/L, the free expansion rate is affected by the dual affects of the concentration of the solution and the high pH.

引言
1 试验材料与方法
2 试验结果与分析
3 结论

表1 土样的物理力学性质<br/>Tab.1 Physical and mechanical properties of soil samples

表1 土样的物理力学性质
Tab.1 Physical and mechanical properties of soil samples

表2 土样的主要化学成分<br/>Tab.2 Main chemical components of soil samples

表2 土样的主要化学成分
Tab.2 Main chemical components of soil samples

图1 在盐溶液中进行的自由膨胀率试验<br/>Fig.1 Free expansion rate test in salt solution

图1 在盐溶液中进行的自由膨胀率试验
Fig.1 Free expansion rate test in salt solution

图2 X射线荧光光谱法<br/>Fig.2 X-ray fluorescence spectrometry

图2 X射线荧光光谱法
Fig.2 X-ray fluorescence spectrometry

图3 层间水分子的构象随时间的变化[11]<br/>Fig.3 The conformation of water molecules between layers changes with time

图3 层间水分子的构象随时间的变化[11]
Fig.3 The conformation of water molecules between layers changes with time

表3 “清洗”后土样的主要化学成分的含量/%<br/>Tab.3 Contents of main chemical components of soil samples after being “washed”/%

表3 “清洗”后土样的主要化学成分的含量/%
Tab.3 Contents of main chemical components of soil samples after being “washed”/%

图4 自由膨胀率与盐溶液浓度的关系<br/>Fig.4 Relationship between free expansion rate and salt solution concentration

图4 自由膨胀率与盐溶液浓度的关系
Fig.4 Relationship between free expansion rate and salt solution concentration

图5 在整个双电层的电势及离子分布示意图<br/>Fig.5 Schematic distribution of potential and irons in the whole electrical double layer

图5 在整个双电层的电势及离子分布示意图
Fig.5 Schematic distribution of potential and irons in the whole electrical double layer

图6 拟半透膜作用示意图<br/>Fig.6 Schematic of semi-membranceous

图6 拟半透膜作用示意图
Fig.6 Schematic of semi-membranceous

图7 自由膨胀率的最大变化率与阳离子价态的关系<br/>Fig.7 Relationship between maximum rate of change of free expansion rate and cation valence

图7 自由膨胀率的最大变化率与阳离子价态的关系
Fig.7 Relationship between maximum rate of change of free expansion rate and cation valence

图8 自由膨胀率与不同钾盐溶液浓度的关系曲线<br/>Fig.8 Relationship between free expansion rate and concentration of different potassium salt solutions

图8 自由膨胀率与不同钾盐溶液浓度的关系曲线
Fig.8 Relationship between free expansion rate and concentration of different potassium salt solutions

图9 自由膨胀率与不同钠盐溶液浓度的关系曲线<br/>Fig.9 Relationship between free expansion rate and concentration of different sodium salt solutions

图9 自由膨胀率与不同钠盐溶液浓度的关系曲线
Fig.9 Relationship between free expansion rate and concentration of different sodium salt solutions

[1]ANH H N, AHN H, JO H Y, et al. Effect of alkaline solutions on bentonite properties[J]. Environmental Earth Sciences, 2017, 76(10):374.
[2]ZHU C M, YE W M, CHEN Y G, et al. Influence of salt solutions on the swelling pressure and hydraulic conductivity of compacted GMZ01 bentonite[J]. Engineering Geology, 2013, 166(10):74-80.
[3]CASTELLANOS E, VILLAR M V, ROMERO E, et al. Chemical impact on the hydro-mechanical behaviour of high density FEBEX bentonite[J], Physics and Chemistry of the Earth, Parts A/B/C, 2008, 33:516-526.
[4]CHEN Y G, ZHU C M, YE W M, et al. Effects of solution concentration and vertical stress on the swelling behavior of compacted GMZ01 bentonite[J]. Applied Clay Science, 2016, 124/125:11-20.
[5]姚传芹, 韦昌富, 马田田, 等. 孔隙溶液对膨胀土力学性质影响[J]. 岩土力学, 2017,38(S2):116-122.
[6]ABDULLAH W S, ALSHIBLI K A, Al-Zou'Bi M S. Influence of pore water chemistry on the swelling behavior of compacted clays[J]. Applied Clay Science, 1999, 15(5):447-462.
[7]KARNLAND O, OLSSON S, NILSSON U, et al. Experimentally determined swelling pressures and geochemical interactions of compacted wyoming bentonite with highly alkaline solutions[J], Physics and Chemistry of the Earth, Parts A/B/C, 2007, 32(1-7):275-286.
[8]陈宝, 张会新, 陈萍. 高碱溶液对高庙子膨润土侵蚀作用的研究[J]. 岩土工程学报, 2013, 35(1):181-186.
[9]陈宝, 张会新, 陈萍. 高碱性溶液对高庙子膨润土溶蚀作用的研究[J]. 岩石力学与工程学报, 2012, 31(7):1478-1483.
[10]LEROY P, TOURNASSAT C, BERNARD O, et al. The electrophoretic mobility of montmorillonite. Zeta potential and surface conductivity effects[J]. Journal of Colloid & Interface Science, 2015, 451:21-39.
[11]KATTI D R, SRINIVASAMURTHY L, KATTI K S. Molecular modeling of initiation of interlayer swelling in Na-montmorillonite expansive clay[J]. Canadian Geotechnical Journal, 2015, 52(9):1385-1395.
[12]EGLOFFSTEIN T A. Natural bentonites: influence of the ion exchange and partial desiccation on permeability and self-healing capacity of bentonites used in GCLs[J]. Geotextiles & Geomembranes, 2001, 19(7):427-444.
[13]叶玲, 张敬阳. 邻菲罗啉对蒙脱石吸附镍离子性能影响[J]. 环境科学学报, 2012, 32(6):1381-1387.
[14]范日东, 杜延军, 陈左波, 等. 受铅污染的土 - 膨润土竖向隔离墙材料的压缩及渗透特性试验研究[J]. 岩土工程学报, 2013, 35(5):841-848.
[15]闵凡飞, 赵晴, 李宏亮, 等. 煤泥水中高岭土颗粒表面荷电特性研究[J]. 中国矿业大学学报, 2013, 42(2):284-290.
[16]谭罗荣. 蒙脱石晶体膨胀和收缩机理研究[J]. 岩土力学, 1997(3):13-18.
[17]MAIO C D. Exposure of bentonite to salt solution: Osmotic and mechanical effects[J]. Geotechnique, 1996, 46(4):695-707.
[18]XU Y, XIANG G, JIANG H, et al. Role of osmotic suction in volume change of clays in salt solution[J]. Applied Clay Science, 2014, 101:354-361.
[19]项国圣, 徐永福, 陈涛, 等. 盐溶液中膨润土膨胀变形的分形模型[J]. 岩土力学, 2017, 38(1):75-80.
[20]RAO S M, SHIVANANDA P. Role of osmotic suction in swelling of salt-amended clays[J]. Canadian Geotechnical Journal, 2005, 42(1):307-315.
[21]徐加放, 孙泽宁, 刘洪军, 等. 分子模拟无机盐抑制蒙脱石水化机理[J]. 石油学报, 2014, 35(2):377-384.
[22]JIANG G, XUAN Y, LI Y, et al. Inhibitive effect of potassium methylsiliconate on hydration swelling of montmorillonite[J]. Colloid Journal, 2014, 76(4): 408-415.
[23]彭昌盛, 张倩, 徐兴永, 等. 团聚 - 分散行为对悬浮液Zeta电位的影响[J]. 中国海洋大学学报(自然科学版), 2010, 40(10):121-126.
[24]叶为民, 黄伟, 陈宝, 等. 双电层理论与高庙子膨润土的体变特征[J]. 岩土力学, 2009, 30(7):1899-1903.
[25]袁勇智, 熊海灵, 李航, 等. 重力场和电解质浓度对胶体凝聚体分形结构的影响[J]. 物理化学学报, 2007(5):688-694.
[26]刘清秉, 项伟, 崔德山, 等. 离子土固化剂改良膨胀土的机理研究[J]. 岩土工程学报, 2011, 33(4):648-654.
[27]王耀强, 赵怡琳, 李玲慧, 等. 海胆状Fe3O4@TiO2磁性纳米介质对Pb2+的选择吸附特性[J]. 化工学报, 2018, 69(1):446-454.

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备注

引言

1 试验材料与方法

2 试验结果与分析

3 结论

期刊信息