Environmental Prediction Model for Dynamic Release of Lead in Contaminated Soil under Washing Remediation

摘要

Adsorption-desorptioncharacteristicsandmodelforleadcontaminatedsoilwithdifferentconcentrationwerestudiedbybatchtestsinlaboratory.ResultsshowedthatLangmuirequationcouldbetterfitisothermaladsorptioncurveoflead,withtheincreasingofleadinsoil,thetimeforleadtoreachequilibriumextended.DesorptionprocessofleadunderthewashingofNa2EDTAcouldbedividedintotwophase,thatwasrapiddesorptionphaseandslowdesorptionstage,andtheturningpointwasabout200min.Dualconstantequationcouldeffectivelyreflectthedesorptionkineticsprocessofleadincontaminatedsoil.Adynamicmodelfordescribingthemigrationprocessofleadincontaminatedsoilunderwashingwasestablishedbasedondesorptionkineticsequation,soilmoisturemigrationequationandsolutetransportequation.Numericalsolutionforthemodelwassolvedandthevalidityofwhichwasverifiedbasedonmonitoringdates.Themigrationlawofleadincontaminatedsoilunderwashingwasobtainedthroughnumericalsimulatingofasimplecondition.