Inordertoinvestigatetheeffectsofmicroorganismsandtheirureaseactivitiesinmacrophyticrootzonesonpollutantremoval,foursmall-scaleplots(SSPs)ofvertical/reverse-verticalflowwetlandsweresetuptodetermine:a)therelationshipbetweentheabundanceofmicroorganismsintherootzonesandwaterpurificationefficiency;andb)therelationshipbetweenureaseactivitiesintherootzonesandpollutantremovalinaconstructedwetlandsystem.Totalnumbersofthemicrobialpopulation(bacteria,fungi,andactinomyces)alongwithureaseactivitiesinthemacrophyticrootzonesweredetermined.Inaddition,therelationshipsbetweenmicrobialpopulationsandureaseactivitiesaswellasthewastewaterpurificationefficienciesoftotalphosphorus(TP),totalKjeldahlnitrogen(TKN),biochemicaloxygendemandin5days(BOD5),andchemicaloxygendemand(COD)werealsoanalyzed.Theresultsshowedthattherewasahighlysignificantpositivecorrelation(r=0.9772,P＜0.01)betweenthenumberofbacteriaintherootzonesandBOD5removalefficiencyandasignificantnegativecorrelation(r=-0.9092,P＜0.05)betweenthenumberoffungiandtheremovalefficiencyofTKN.Meanwhile,therewasasignificantpositivecorrelation(r--0.8830,P＜0.05)betweenureaseactivitiesintherootzonesandtheremovalefficiencyofTKN.Thus,duringwastewatertreatmentinaconstructedwetlandsystem,microorganismandureaseactivitiesintherootzoneswereveryimportantfactors.
