Enhanced adsorption treatment of landfill leachate using coal⁃based activated carbon modified by nitric acid
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Graphical Abstract
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Abstract
The coal based powder activated carbon was modified by nitric acid, the adsorption propertiesofactivatedcarbonunderdifferentmodificationconditionswasinvestigatedthemodifiedacti⁃ vatedcarbonobtainedundertheoptimalmodificationconditionswasusedfortheadvancedtreatmentof landfillleachatetoinvestigatedthepollutantsremovalefficiencywithvaryingdifferentparameterssuch as input dosage and absorption time*The ratio of mesoporous aperture diameter and absorption propertiesofactivatedcarbonattainedthehighestaftermodification2hwiththeconcentrationofnitric acid15% andthetemperatureofmodification60℃*TheremovalratesofCOD,NH3-N,TNandCr6+were79*0%,43*3%,52*6% and100%,respectively,whenthedosageofmodifiedactivatedcarbon was4g/150mg/L,theadsorptiontimewas12h,andthesolutionpHof7*Andaftermodification,the removalrateofCODandTNincreasedby10*1% and17*3% comparedwithpreviousactivatedcar⁃ bon*ItwasfoundthatthereactionofadsorptionanddegradationofCODin12hwasmoreconsistent withzeroorderreactionwhenanalyzingthekineticsofCODadsorptionanddegradation*Inaddition, thenonlinearfittingofdegradationprocessindicatesthatthedegradationprocesscanbesimulatedand predictedby Logistic function model*A better regenerative result was achieved by using ultrasonic methodwiththeoptionsofpHwas4*5andultrasonictimemorethan2h*TakingUV254 asreference value,theregenerativepost⁃treatmentratewasreducedby12% comparedwiththeinitialusingwhich indicatedthatthenitricacidmodifiedcoal⁃basedactivatedcarbonhasgoodregenerativecapacityand couldbereused*
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