重金属镉污染对土体力学特性的影响及机理分析
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摘要
为了研究重金属镉(Cd)对土体力学特性的影响规律及其微观机理,开展了不同Cd含量污染土强度、渗透、剪切特性、压汞和扫描电镜试验研究。力学特性试验结果表明:重金属Cd会劣化土体力学特性;随着Cd含量的增加,土体的抗压强度、剪切强度和黏聚力显著降低;而渗透系数、内摩擦角明显增大。扫描电镜试验结果表明:Cd使土颗粒发生团聚,Cd污染土出现大的团聚体,大颗粒增多,土体表面变得比较粗糙,土颗粒之间的接触形式增多,出现点-面接触和边-面接触;且团聚体间的孔隙较大。压汞试验表明:随着Cd含量的增加,污染土中孔径大于1μm的孔隙体积明显增加。污染土的微观结构和孔隙分布的改变是Cd污染土力学特性变化的本质原因。
To provide the effect cadmium contamination on the mechanical properties and mechanism analysis of the soil,unconfined compressive strength test,permeability test,shear test,mercury injection test and scanning electron microscope test were conducted to investigate the mechanical properties of contaminated soils with different cadmium content. Results showed that cadmium degradate of mechanical properties of soil. The unconfined compressive strength,shear strength and cohension of the cadmium contaminated soil decreased with cadmium content,but the hydraulic conductivity and internal friction angle increased. Scanning electron microscope test showed that a larger aggregation formation,with a larger void space in soils as the cadmium content increased. the laminated sheet structure of soil will be gradually destroyed. The contact between the soil particles changed from surface-tosurface contact to point-to-surface contact or edge-to-surface contact. Mercury injection test results show that the total void volume increased as the cadmium content. The cadmium increased the pore volume of soil pores,which the diameter larger than 1 μm. The change in mechanical properties of cadmium contaminated soil can be attributed to the change in the microstructure and pore volume distribution of cadmium contaminated soil.
To provide the effect cadmium contamination on the mechanical properties and mechanism analysis of the soil,unconfined compressive strength test,permeability test,shear test,mercury injection test and scanning electron microscope test were conducted to investigate the mechanical properties of contaminated soils with different cadmium content. Results showed that cadmium degradate of mechanical properties of soil. The unconfined compressive strength,shear strength and cohension of the cadmium contaminated soil decreased with cadmium content,but the hydraulic conductivity and internal friction angle increased. Scanning electron microscope test showed that a larger aggregation formation,with a larger void space in soils as the cadmium content increased. the laminated sheet structure of soil will be gradually destroyed. The contact between the soil particles changed from surface-tosurface contact to point-to-surface contact or edge-to-surface contact. Mercury injection test results show that the total void volume increased as the cadmium content. The cadmium increased the pore volume of soil pores,which the diameter larger than 1 μm. The change in mechanical properties of cadmium contaminated soil can be attributed to the change in the microstructure and pore volume distribution of cadmium contaminated soil.
引文
1杜盼晓,张宇,魏闻语,等.水泥固化重金属污染土的强度及环境特性:试验及数值模拟[J].科学技术与工程,2018,18(21):146-154Du Panxiao,Zhang Yu,Wei Wenyu,et al.Strength and environmental characteristics of cement solidified heavy metal contaminated soil:Experiment and numerical simulation[J].Science Technology and Engineering,2018,18(21):146-154
2 张亭亭,李江山,王平.磷酸镁水泥固化铅污染土的力学特性试验研究及微观机制[J].岩土力学,2016,37(增刊2):279-286Zhang Tingting,Li Jiangshan,Wang Ping.Experimental study of mechanical and microstructure properties of magnesium phosphate cement treated lead contaminated soils[J].Rock and Soil Mechanics,2016,37(S2):279-286
3 Turer D.Effect of heavy metal and alkali contamination on the swelling properties of kaolinite[J].Environmental Geology,2007,52(3):421-425
4 Shariatmadari N,Salami M,Fard M K.Effect of inorganic salt solutions on some geotechnical properties of soil-bentonite mixtures as barriers[J].International Journal of Civil Engineering,2011,9(2):103-110
5 张志红,李红艳,师玉敏.重金属Cu2+污染土渗透特性试验及微观结构分析[J].土木工程学报,2014,47(12):122-129Zhang Zhihong,Li Hongyan,Shi Yumin.Experimental study on permeability properties and micro-structure of clay contaminated by Cu2+.China Civil Engineering Journal,2014,47(12):122-129
6 饶为国,马福荣,陈日高.重金属污染对土压实性及抗剪强度影响的试验研究[J].工业建筑,2013,43(4):92-97Rao Weiguo,Ma Furong,Chen Rigao.Experimental research on the effect of the heavy metal pollutants on soil compactness and shear strength[J].Industrial Construction,2013,43(4):92-97
7 刘志彬,方伟.锌离子污染对膨润土一维压缩特性影响试验研究[J].岩土力学,2013,34(8):2211-2217Liu Zhibin,Fang Wei.Experimental study of influence of zinc ions on one-dimensional compressibility of bentonite[J]Rock and Soil Mechanics,2013,34(8):2211-2217
8 张亭亭,王平,李江山.养护龄期和铅含量对磷酸镁水泥固化/稳定化铅污染土的固稳性能影响规律及微观机制[J].岩土力学,2018,39(6):2115-2123Zhang Tingting,Wang Ping,Li Jiangshan.Effect of curing time and lead concentration on mechanical properties of lead-contaminated soils stabilized by magnesium phosphate cement[J].Rock and Soil Mechanics,2018,39(6):2115-2123
9 Liu L,Chen H,Cai P.Immobilization and phytotoxicity of Cd in contaminated soil amended with chicken manure compost[J].Journal of Hazardous Materials,2009,163(2-3):563-567
10 Jiang J,Xu R,Jiang T,et al.Immobilization of Cu(II),Pb(II)and Cd(II)by the addition of rice straw derived biochar to a simulated polluted Ultisol[J].Journal of Hazardous Materials,2012,229:145-150
11 中华人民共和国水利部土工试验方法标准:GB/T 50123—1999[S].北京:中国计划出版社,1999The Ministry of Water Resources of the People’s Republic of China.Standard for soil test method:GB/T 50123—1999[S].Beijing:China Planning Press,1999
12 储亚,刘松玉,蔡国军.重金属锌污染淤泥质粉质粘土物理特性试验研究[J].地下空间与程学报,2014,10(6):1312-1316Chu Ya,Liu Songyu,Cai Guojun.Study on the physical and electrical properties of silty clay contaminated by heavy metal zinc[J].Chinese Journal of Underground Space and Engineering,2014,10(6):1312-1316
13 查甫生,刘晶晶,夏磊.重金属污染土的工程性质试验研究[J].地下空间与工程学报,2014,10(2):1982-1985Zha Fusheng,Liu Jingjing,Xia Lei.Engineering properties of heavy metal contaminated soil[J].Chinese Journal of Underground Space and Engineering,2014,10(2):1982-1985
14 Quigley R M.Clay minerals against contaminant migration[J].Geotech News,North Am Geotech Comm,1993,11(4):44-46
15 Lambe T W.The structure of compacted clay[J].Journal of the Soil Mechanics and Foundations Division,1958,84(2):1-34.
16 Horpibulsuk S,Rachan R,Raksachon Y.Role of fly ash on strength and microstructure development in blended cement stabilized silty clay[J].Soils and Foundations,2009,49(1):85-98
2 张亭亭,李江山,王平.磷酸镁水泥固化铅污染土的力学特性试验研究及微观机制[J].岩土力学,2016,37(增刊2):279-286Zhang Tingting,Li Jiangshan,Wang Ping.Experimental study of mechanical and microstructure properties of magnesium phosphate cement treated lead contaminated soils[J].Rock and Soil Mechanics,2016,37(S2):279-286
3 Turer D.Effect of heavy metal and alkali contamination on the swelling properties of kaolinite[J].Environmental Geology,2007,52(3):421-425
4 Shariatmadari N,Salami M,Fard M K.Effect of inorganic salt solutions on some geotechnical properties of soil-bentonite mixtures as barriers[J].International Journal of Civil Engineering,2011,9(2):103-110
5 张志红,李红艳,师玉敏.重金属Cu2+污染土渗透特性试验及微观结构分析[J].土木工程学报,2014,47(12):122-129Zhang Zhihong,Li Hongyan,Shi Yumin.Experimental study on permeability properties and micro-structure of clay contaminated by Cu2+.China Civil Engineering Journal,2014,47(12):122-129
6 饶为国,马福荣,陈日高.重金属污染对土压实性及抗剪强度影响的试验研究[J].工业建筑,2013,43(4):92-97Rao Weiguo,Ma Furong,Chen Rigao.Experimental research on the effect of the heavy metal pollutants on soil compactness and shear strength[J].Industrial Construction,2013,43(4):92-97
7 刘志彬,方伟.锌离子污染对膨润土一维压缩特性影响试验研究[J].岩土力学,2013,34(8):2211-2217Liu Zhibin,Fang Wei.Experimental study of influence of zinc ions on one-dimensional compressibility of bentonite[J]Rock and Soil Mechanics,2013,34(8):2211-2217
8 张亭亭,王平,李江山.养护龄期和铅含量对磷酸镁水泥固化/稳定化铅污染土的固稳性能影响规律及微观机制[J].岩土力学,2018,39(6):2115-2123Zhang Tingting,Wang Ping,Li Jiangshan.Effect of curing time and lead concentration on mechanical properties of lead-contaminated soils stabilized by magnesium phosphate cement[J].Rock and Soil Mechanics,2018,39(6):2115-2123
9 Liu L,Chen H,Cai P.Immobilization and phytotoxicity of Cd in contaminated soil amended with chicken manure compost[J].Journal of Hazardous Materials,2009,163(2-3):563-567
10 Jiang J,Xu R,Jiang T,et al.Immobilization of Cu(II),Pb(II)and Cd(II)by the addition of rice straw derived biochar to a simulated polluted Ultisol[J].Journal of Hazardous Materials,2012,229:145-150
11 中华人民共和国水利部土工试验方法标准:GB/T 50123—1999[S].北京:中国计划出版社,1999The Ministry of Water Resources of the People’s Republic of China.Standard for soil test method:GB/T 50123—1999[S].Beijing:China Planning Press,1999
12 储亚,刘松玉,蔡国军.重金属锌污染淤泥质粉质粘土物理特性试验研究[J].地下空间与程学报,2014,10(6):1312-1316Chu Ya,Liu Songyu,Cai Guojun.Study on the physical and electrical properties of silty clay contaminated by heavy metal zinc[J].Chinese Journal of Underground Space and Engineering,2014,10(6):1312-1316
13 查甫生,刘晶晶,夏磊.重金属污染土的工程性质试验研究[J].地下空间与工程学报,2014,10(2):1982-1985Zha Fusheng,Liu Jingjing,Xia Lei.Engineering properties of heavy metal contaminated soil[J].Chinese Journal of Underground Space and Engineering,2014,10(2):1982-1985
14 Quigley R M.Clay minerals against contaminant migration[J].Geotech News,North Am Geotech Comm,1993,11(4):44-46
15 Lambe T W.The structure of compacted clay[J].Journal of the Soil Mechanics and Foundations Division,1958,84(2):1-34.
16 Horpibulsuk S,Rachan R,Raksachon Y.Role of fly ash on strength and microstructure development in blended cement stabilized silty clay[J].Soils and Foundations,2009,49(1):85-98