ORIGINALARTICLEActaGeochim(2023)42(1):125–135https://doi.org/10.1007/s11631-022-00566-7KeywordsInorganicions·Humin·Phenanthrene·Adsorption·Soil·Karst1IntroductionThefateofPAHsinthenaturalenvironmentismainlycon-trolledbyphysicochemicalprocessessuchasadsorption/desorption(Ukalska-Jarugaetal.2020;Schneckenburger&Thiele-Bruhn2020;Chenetal.2021;Wangetal.2021),andtheirenvironmentaltoxiceffectsarecloselyrelatedtotheirbioavailability.However,thetraditionalorganicpol-lutionriskassessmentisstillmainlybasedontheobservedconcentrationsoforganicpollutants,whichmayleadtooverestimationoftheshort-termeffectsoforganicpollut-antsandunderestimationoftheirlong-termeffectsinstud-ies(Alexander2000;Louchart&Voltz2007;Qianetal.2020a,b).Alargenumberofstudieshaveshownthatsoilorganicmatter(SOM)isanimportantcomponentfortheadsorptionoftoxicpollutants(Lamichhaneetal.2016;Anetal.2021).AsapartofSOM,HMisthemaincomponenttocontroltheadsorptionofPAHsinsoil.StudieshaveshownthatHMisthemomentous“hardcarbon”insoil,whichperformsnonlinearadsorptionofPAHsbykindsofwayssuchassurfacehighenergysiteandporeadsorption(Chenetal.2017).ManyreportshavebeenconductedonPAHsinkarstecology(Shaoetal.2014;Yuetal.2018;Chengetal.2021).Lanetal(2018)reportedthatthemigrationofPAHsinkarstgroundwatercloselyrelatedtoseasonalrain-fall.Zhuetal.(2022)illustratedthathighringPAHsweremoreenrichedinthesoiloftypicalkarsttroughvalleysinChongqing,andPAHsofsoilgenerallycausedalowriskofcarcinogenicity.Qianetal(2020)showedthatPAHsoflowmolecularweightwasmainlyfoundinthekarstcavesedi-ment,andPAHsdistributionhadnosignificantrelationshipwiththesedimentparticlesize.Chenetal(2022)shownthatparticle-promotedtransportwithrapidwaterflowwasAbstractHumin(HM)isthemainorganicmattercomponenttoaffectthemigrationandtransformationofpolycyclicaro-matichydrocarbons(PAHs)insoil.Thestudyoninflu-enceofthemorphologychangeofinorganicionsontheadsorptionofPAHsinsoilanditsorganicmatterisstillrareatmicroscopicscale.Inthispaper,yellowsoilhumin(YS-HM)andlimesoilhumin...
