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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。
Abstract：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 Cl- 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 σ 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.
[1]Graf D L.Chemical osmosis,reverse chemical osmosis,and the origin of subsurface brines.Geochimica et Cosmochimica Acta[J].1982,46(8):1431-1448.
[2]Peter G,Oduor F X,Casey A Podoll.Modeling of concentration polarization layer evolution and breakthrough concentrations in dead-end hyperfiltration.Membrane Science[J].2006,285:376-384.
[3]Garavito A M,De Cannière P,Kooi H.In situ chemical osmosis experiment in the Boom Clay at the Mol underground research laboratory.Physics and Chemistry of the Earth[J].2007,32(1/2/3/4/5/6/7):421-433.
[4]Marshall C E.The electrochemical properties of mineral membranes.VIII The theory of seltive membrane behavior.The Journal of Physical Chemistry[J].1948,52:1284-1295.
[5]McKelvey J G,Milne I H.Permeability and salt-filtering properties of compacted clay.Clays and Clay Minerals[J].1963,13:250-251.
[6]Kemper W D,Rollins J B.Osmotic effciency coeffcients across compacted clays.Soil Science Society of America Journal[J].1966,30:529-534.
[7]Kharaka Y K,Berry F A.Simultaneous flow of water and solutes through geologic membranes.Geochimica et Cosmochimica Acta[J].1973,37:2577-2603.
[8]Fritz S J,Marine I W.Experimental support for a predictive osmotic model of clay membranes.Geochimica et Cosmochimica Acta[J].1983,47:1515-1522.
[9]Haydon P R,Graf D L.Studies of smectite membrane behavior:temperature dependence,20~180℃.Geochimica et Cosmochimica Acta[J].1986,50:115-121.
[10]Whitworth T M,Fritz S J.Electrolyte-induced solute permeability effects in compacted smectite membranes.Applied Geochemistry[J].1994,9:533-546.
[11]Saindon R M.Relevance of Clay Membrane Properties of Clay-rich Geologic Materials to Water-related Engineering Issues[D].Rolla:Univ Missouri,2004.
[12]河北省环境地质勘查院.曹妃甸港港口环境地质调查及脆弱性评价报告[R].石家庄,2006.
[13]Megan Hart,Whitworth T M,Eliot Atekwana.Hyperfiltration of sodium chloride through kaolinite membranes under relatively low-heads-implications for groundwater assessment.Applied Geochemistry[J].2008,23(6):1691-1702.
[14]席永慧,冯世进.粘质土壤的膜性能研究进展.同济大学学报[J].2009,37(2):187-191.
[15]Whitworth T M.Steady-state mathematical modeling of geological membrane effects in aquifer systems[C].Washington:Joint Conference on the Environment,1998,p37-40.
[16]Megan Hart,Whitworth T M.Hyperfiltration of potassium nitrate through clay membranes under relatively low-head conditions.Geochimica et Cosmochimica Acta[J].2005,69(20):4817-4823.
[17]Megan Hart,Whitworth T M.Low head sodium phosphate and nitrate hyperfiltration through thin kaolinite and smectite layers-Application to engineered systems.Applied Clay Science[J].2006,33(1):52-58.
[18]Clifton M.Polarization de concentration dans divers procedes de separation a membrane[D].Toulhouse:Universite Paul Sabatier,France,1982.
[19]Whitworth T M,Haneberg W C,Mozley P S,Goodwin L B.Solute sieving on pulverized quartz sand-experimental results and implications for the membrane behavior of fault gouge[C].Washington:American Geophysical Union,1999,p149-158.
[20]刘建国,王洪涛,聂永丰.多孔介质中溶质有效扩散系数预测的分形模型.水科学进展[J].2004,15(4):458-461.
[21]Lide D.CRC Handbook of Chemistry and Physics[M].New Jersey:CRC Press,2003.
[22]Keijzer T J,Loch J P.Chemical osmosis in compacted dredging sludge.Soil Science Society of America Journal[J].2001,65:1045-1055.
[23]Keijzer T J,Kleingeld P J,Loch J P.Chemical osmosis in compacted clayey material and the prediction of water transport.Engineering Geology[J].1999,(53):151-159.
[24]Jong-Beom Kang,Shackelford C D.Clay membrane testing using a flexible-wall cell under closed-system boundary conditions.Applied Clay Science[J].2009,(44):43-58.
[25]吴吉春,薛禹群,张志辉.海水入侵含水层中水-岩间阳离子交换的实验研究.南京大学学报[J].1996,32(1):71-76.
[26]Abhijit Majhi,Monash P,Pugazhenthi G.Fabrication and characterization ofγ-Al2O3–clay composite ultrafiltration membrane for the separation of electrolytes from its aqueous solution.Membrane Science[J].2009,340:181-191.
[27]何璟.纳滤膜表面荷电性能的研究[D].天津:天津大学,2007.
基本信息:
DOI：10.16026/j.cnki.iea.2013.06.003
中图分类号:O647
引用信息:
[1]左文喆,徐叶净,王英,等.粘性土膜效应的实验研究[J].离子交换与吸附,2013,29(06):551-560.DOI:10.16026/j.cnki.iea.2013.06.003.
基金信息:
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