地下水中Tween80对DNAPL运移和分布的影响
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摘要
选用地下环境中普遍存在的四氯乙烯(PCE)为典型DNAPLs污染物,建立二维砂箱模型,研究一种人为引入表面活性剂Tween 80对粗砂介质中DNAPLs迁移和分布的影响.测定了含不同浓度Tween 80水溶液/石英砂/PCE三相体系下的液/液界面张力及PCE在石英介质表面的接触角,结果表明PCE在石英砂表面的接触角随着Tween 80浓度的增大而增大,PCE/水的界面张力随着Tween 80浓度的增大而减小,Tween 80浓度在CMC值附近时变化急剧.随后的二维砂箱实验定量描述地下水中表面活性剂Tween 80对PCE的迁移和最终形态的影响.由于Tween 80可以使石英砂介质由水相润湿转变为中间润湿或油相润湿态,相应地在20～30目的粗砂均质介质中Tween 80对DNAPLs迁移存在明显影响.背景溶液中表面活性剂的存在使得DNAPL的垂直运移速度减小,垂向迁移距离减小,最终使得被截留在运移路径上的残留PCE增加.和纯水流情况下相比,地下水中含有表面活性物剂Tween 80时,使得DNPAL污染羽向水流方向偏移减弱,污染羽展布面积与纯水情形下相比,在垂向上均明显减小,并且以较大饱和度残留的DNAPL量增加.
How artificial surfactant Tween 80 in groundwater affect ubiquitous tetrachloroethylene(PCE) migration and distribution in coarse porous media was investigated in this work. Batch experiments were first conducted to measure the contact angles and interfacial tensions(IFT) between PCE and quartz surface in water containing different amount of Tween 80. Results showed that the contact angle increased and IFT decreased with the increased concentration of Tween 80, and the effects were more obvious near the CMC value. Three 2-D sandboxexperiments were then conducted.Correspondingly, Tween 80 showed strong effects on the migration and distribution of PCE in the coarse porous media due to its ability to change the medium wettability from water-wet into intermediate/NAPL-wet. The presence of surfactant in the background solution decreased the vertical migration rate of DNAPL,decreased the vertical migration distance, and eventually increased the residual PCE trapped in the migration path. Compared with the situation without surfactant, the Tween 80 in groundwater weakened the tendency of PCE plumes deflect to the direction of water flow. Compared with the water-only case, the distribution area of PCE plumes decreased significantly in the vertical direction, but the amount of DNAPL residues with greater saturation increased.
How artificial surfactant Tween 80 in groundwater affect ubiquitous tetrachloroethylene(PCE) migration and distribution in coarse porous media was investigated in this work. Batch experiments were first conducted to measure the contact angles and interfacial tensions(IFT) between PCE and quartz surface in water containing different amount of Tween 80. Results showed that the contact angle increased and IFT decreased with the increased concentration of Tween 80, and the effects were more obvious near the CMC value. Three 2-D sandboxexperiments were then conducted.Correspondingly, Tween 80 showed strong effects on the migration and distribution of PCE in the coarse porous media due to its ability to change the medium wettability from water-wet into intermediate/NAPL-wet. The presence of surfactant in the background solution decreased the vertical migration rate of DNAPL,decreased the vertical migration distance, and eventually increased the residual PCE trapped in the migration path. Compared with the situation without surfactant, the Tween 80 in groundwater weakened the tendency of PCE plumes deflect to the direction of water flow. Compared with the water-only case, the distribution area of PCE plumes decreased significantly in the vertical direction, but the amount of DNAPL residues with greater saturation increased.
引文
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[11]Hsu H L,Demond A H.Influence of organic acid and organic base interactions on interfacial properties in NAPL-water systems[J].Environmental Science and Technology,2007,41(3):897-902.
[12]Chen H,Gao B,Li H.Effects of pH and ionic strength on sulfamethoxazole and ciprofloxacin transport in saturated porous media[J].Journal of Contaminant Hydrology,2011,126(2):29-36.
[13]程洲,徐红霞,吴吉春,等.盐度对多孔介质中DNAPL运移和分布的影响[J].水文地质工程地质,2017,44(4):142-149.Cheng Z,Xu H,Wu J,et al.Effect of salinity on DNAPL migration and distribution in saturated porous media.Hydrogeology&Engineering Geology 2017,4:142-150.
[14]Lee M,Kang H,Do W.Application of nonionic surfactant-enhanced in situ flushing to a diesel contaminated site.Water research,2005,39:139-146.
[15]Ramsburg C A,Abriola L M,Pennell K D,et al.Stimulated microbial reductive dechlorination following surfactant treatment at the Bachman Road site.Environmental science&technology,2004,38:5902-5914.
[16]Cheng Z,Gao B,Xu H,et al.Effects of surface active agents on DNAPL migration and distribution in saturated porous media.Science of the total environment,2016,571:1147-1154.
[17]Taylor T P,Pennell K D.Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses 1.Experimental studies[J].Journal of Contaminant Hydrology,2001,48(3):325-350.
[18]Suchomel E J,Pennell K D.Reductions in contaminant mass discharge following partial mass removal from DNAPL source zones[J].Environmental Science and Technology,2006,40(19):6110-6116.
[19]Suchomel E J,Ramsburg C A,Pennell K D.Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants[J].Journal of Contaminant Hydrology,2007,94:195-214.
[20]Powers S E,Anckner,W H,Seacord T F.Wettability of NAPL-contaminated sands[J].Journal of Environmental Engineering,1996,122(10):889-896.
[21]Ye S J,Sleep B E,Chien C.The impact of methanogenesis on flow and transport in coarse sand[J].Journal of Contaminant Hydrology,2009,103(2):48-57.
[22]Bob M M,Brooks M C,Wood A L.A modified light transmission visualization method for DNAPL saturation measurements in 2-Dmodels[J].Advances In Water Resources,2008,31(5):727-742.
[23]Niemet M R,Selker J S.A new method for quantification of liquid saturation in 2D translucent porous media systems using light transmission[J].Advances in Water Resources,2001,24(6):651-666.
[24]Jeong S W,Yavuz Corapcioglu M.Force analysis and visualization of NAPL removal during surfactant-related floods in a porous medium[J].Journal of Hazardous Materials,2005,A126:8-13.
[25]Denis M O,Sleep B E.Hot water flushing for immiscible displacement of a viscous NAPL[J].Journal of Contaminant Hydrology,2007,91:247-266.
[26]Conrad S H,Glass R J,Peplinski W J.Bench-scale visualization of DNAPL remediation process in analog heterogeneous aquifers:surfactant floods and in situ oxidation using permanganate[J].Journal of Contaminant Hydrology,2002,58:13-19.
[27]Phelan T J,Lemke L D,Bradford,S A,et al.Influence of textural and wettability variations on predictions of DNAPL persistence and plume development in saturated porous media[J].Advances in Water Resources,2004,27:411-427.
[28]Luciano A,Viotti P,Papini M P.Laboratory investigation of DNAPLmigration in porous media[J].Journal of Hazardous Materials,2010,176(1):1006-1017.
[29]Suchomel E J,Pennell K D.Reductions in contaminant mass discharge following partial mass removel from DNAPL source zone[J].Environmental Science and Technology,2006,40(19):6110-6116.
[2]程洲,吴吉春,徐红霞,等.DNAPL在透镜体及表面活性剂作用下的运移研究[J].中国环境科学,2014,34(11):2888-2896.Cheng Z,Wu J,Xu H,et al.Investigation of the migration characteristic of DNAPL in aquifer with lenses and under the action of surfactant flushing[J].China Environment Science 2014,34:2888-2896.
[3]Koch J,Nowak W.Predicting DNAPL mass discharge and contaminated site longevity probabilities:Conceptual model and high-resolution stochastic simulation[J].Water Resources Research2015,51:806-831.
[4]Molnar I L,O'Carroll D M,Gerhard J I.Impact of surfactant-induced wettability alterations on DNAPL invasion in quartz and iron oxide-coated sand systems[J].Journal of Contaminant Hydrology2011,119:1-12.
[5]Zheng F,Gao B,Sun Y,et al.Removal of tetrachloroethylene from homogeneous and heterogeneous porous media:Combined effects of surfactant solubilization and oxidant degradation[J].Chemical Engineering Journal,2016,283:595-603.
[6]Pennell K D,Pope G A,Abriol L M.Influence of viscous and buoyancy forces on the mobilization of residual tetrachloroe-thylene during surfactant flushing[J].Environmental Science and Technology,1996,30(4):1328-1335.
[7]Totten C T,Annable M D,Jawitz J W,et al.Fluid and porous media property effects on dense nonaqueous phase liquid migration and contaminant mass flux[J].Environmental Science and Technology,2007,41(5):1622-1627.
[8]Powers S E,Anckner W H,Seacord T F.Wettability of NAPL-contaminated sands[J].Journal of Environmental Engineering,1996,122:889-896.
[9]O'Carroll D M,Mumford K G,Abriola L M,et al.Influence of wettability variations on dynamic effects in capillary pressure[J].Water Resources Research 2010,46.
[10]Barranco F T,Dawson A H,Christener J,et al.Influence of aqueous pH and ionic strength on the Wettability of Quartz in the Presence of Dense Non-Aqueous-Phase Liquids[J].Environmental Science and Technology,1997,31(3):676-681.
[11]Hsu H L,Demond A H.Influence of organic acid and organic base interactions on interfacial properties in NAPL-water systems[J].Environmental Science and Technology,2007,41(3):897-902.
[12]Chen H,Gao B,Li H.Effects of pH and ionic strength on sulfamethoxazole and ciprofloxacin transport in saturated porous media[J].Journal of Contaminant Hydrology,2011,126(2):29-36.
[13]程洲,徐红霞,吴吉春,等.盐度对多孔介质中DNAPL运移和分布的影响[J].水文地质工程地质,2017,44(4):142-149.Cheng Z,Xu H,Wu J,et al.Effect of salinity on DNAPL migration and distribution in saturated porous media.Hydrogeology&Engineering Geology 2017,4:142-150.
[14]Lee M,Kang H,Do W.Application of nonionic surfactant-enhanced in situ flushing to a diesel contaminated site.Water research,2005,39:139-146.
[15]Ramsburg C A,Abriola L M,Pennell K D,et al.Stimulated microbial reductive dechlorination following surfactant treatment at the Bachman Road site.Environmental science&technology,2004,38:5902-5914.
[16]Cheng Z,Gao B,Xu H,et al.Effects of surface active agents on DNAPL migration and distribution in saturated porous media.Science of the total environment,2016,571:1147-1154.
[17]Taylor T P,Pennell K D.Surfactant enhanced recovery of tetrachloroethylene from a porous medium containing low permeability lenses 1.Experimental studies[J].Journal of Contaminant Hydrology,2001,48(3):325-350.
[18]Suchomel E J,Pennell K D.Reductions in contaminant mass discharge following partial mass removal from DNAPL source zones[J].Environmental Science and Technology,2006,40(19):6110-6116.
[19]Suchomel E J,Ramsburg C A,Pennell K D.Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants[J].Journal of Contaminant Hydrology,2007,94:195-214.
[20]Powers S E,Anckner,W H,Seacord T F.Wettability of NAPL-contaminated sands[J].Journal of Environmental Engineering,1996,122(10):889-896.
[21]Ye S J,Sleep B E,Chien C.The impact of methanogenesis on flow and transport in coarse sand[J].Journal of Contaminant Hydrology,2009,103(2):48-57.
[22]Bob M M,Brooks M C,Wood A L.A modified light transmission visualization method for DNAPL saturation measurements in 2-Dmodels[J].Advances In Water Resources,2008,31(5):727-742.
[23]Niemet M R,Selker J S.A new method for quantification of liquid saturation in 2D translucent porous media systems using light transmission[J].Advances in Water Resources,2001,24(6):651-666.
[24]Jeong S W,Yavuz Corapcioglu M.Force analysis and visualization of NAPL removal during surfactant-related floods in a porous medium[J].Journal of Hazardous Materials,2005,A126:8-13.
[25]Denis M O,Sleep B E.Hot water flushing for immiscible displacement of a viscous NAPL[J].Journal of Contaminant Hydrology,2007,91:247-266.
[26]Conrad S H,Glass R J,Peplinski W J.Bench-scale visualization of DNAPL remediation process in analog heterogeneous aquifers:surfactant floods and in situ oxidation using permanganate[J].Journal of Contaminant Hydrology,2002,58:13-19.
[27]Phelan T J,Lemke L D,Bradford,S A,et al.Influence of textural and wettability variations on predictions of DNAPL persistence and plume development in saturated porous media[J].Advances in Water Resources,2004,27:411-427.
[28]Luciano A,Viotti P,Papini M P.Laboratory investigation of DNAPLmigration in porous media[J].Journal of Hazardous Materials,2010,176(1):1006-1017.
[29]Suchomel E J,Pennell K D.Reductions in contaminant mass discharge following partial mass removel from DNAPL source zone[J].Environmental Science and Technology,2006,40(19):6110-6116.