简介：Theadsorptioncapabilityofloamsoilfornano-TiO2affectedbytheamountandintensityofleachedwaterhasbeeninvestigatedbysimulatingthenaturalrainfallprocessundertheleachingcondition.Theresultsshowthattheamountandtheintensityofleachedwateraretwoimportantfactorsaffectingtheadsorptioncapabilityofloamsoilfornano-TiO2.Theresultsindicatethatthedepthoftheloamsoilcontainingamaximalamountofnano-TiO2isproportionaltotheamountofleachedwater,whileitisinverselyproportionaltotheintensityofleachedwater,ataconstantamountoftheleachedwater.Itwasalsofoundthattheadsorptioncapabilityofsoilsfornano-TiO2canbeimprovedbyaddingothermaterials,suchasdissolvedorganicmatter(DOM),bentoniteandstraw.ItwasfoundthatDOMisthebestsorbentforimprovingtheadsorptioncapabilityofloamsoilfornano-TiO2,followedbybentonite,whilestrawisnotsuitableforthemodificationofloamsoil.Theimprovementofadsorptioncapabilityofloamsoildependsontheamountoftheseadditives.Nano-TiO2canbeeffectivelyadsorbedonthesurfacelayerofloamsoilcontaininganappropriateamountofadditive.

简介：Inthispaper,withK+,Ca2+andFe3+astheobjectsofstudy,retardationofsoil–bentonite(SB)barriermaterialsformetalionswithdifferentvalencesisinvestigated,andtheadsorptionmechanism,migrationpatternsandpermeationbehaviorareexploredsoastoprovideatheoreticalbasisfortheirapplication.TheresultsshowthattheadsorptionprocessformetalionswithdifferentvalencesbySBbarriermaterialsisfast,andthehigherthevalence,thegreatertheadsorptioncapacity.Thefttingoftheadsorptionprocessconformstopseudo-second-orderadsorptionkineticsandLangmuir–Freundlichadsorptionequation,whichexplainsthatchemicaladsorptionisthedominatingstateandthattheSBsurfacehascertainheterogeneity.ThepermeabilitycoeffcientofK+,Ca2+andFe3+inSBeachhasamaximumandthehigherthevalence,thesoonerthemaximumappears.Alsothehigherthevalence,themoreobvioustheeffectonSBretardationperformance;andthesoonertheionbreaksthroughthebarrierwallcompletely,thatis,thewall’sretardationperformanceforhighervalentionsmaydecline.