A-low-cost-three-dimensional-sample-collection-array-to-evaluate-and-monitor-constructed-wetlands

ecologicalengineering33(2008)83–90availableatwww.sciencedirect.comjournalhomepage:www.elsevier.com/locate/ecolengAlow-costthree-dimensionalsamplecollectionarraytoevaluateandmonitorconstructedwetlandsC.F.Williams∗,F.J.AdamsenUSDA-ARS,USAridLandAgriculturalResearchCenter,21881NCardonLn.,Maricopa,AZ85238,UnitedStatesarticleinfoArticlehistory:Received2November2007Receivedinrevisedform7February2008Accepted17February2008Keywords:WetlandSamplingMonitoringabstractArtificiallyconstructedwetlandsaregainingacceptanceasalow-costtreatmentalterna-tivetoremoveanumberofundesirableconstituentsfromwater.Wetlandscanbeusedtophysicallyremovecompoundssuchassuspendedsolidsthroughsedimentation.Dissolvednutrients,biochemicaloxygendemand,heavymetals,andpotentiallyharmfulanthro-pogeniccompoundscanallberemovedinconstructedwetlandsthroughgeochemicalandbiologicalprocesses.Samplecollectiontoevaluatetheeffectivenessoftreatmentandtomonitorthestatusofwetlandsisusuallyonlyconductedattheinletandoutletofthewetlandduetocostconstraints.Tobetterunderstandtheinternalhydrologyandbiogeo-chemicalprocessesoperatingwithinthewetlandmoreintensivesamplingisneededthatdoesnotinterferewiththehydraulicsofthesystem.Anewrelativelylow-costsamplecollec-tiondesignhasbeendevelopedusingmostlyoff-the-shelfpartsthatallowsforpermanent,internal,three-dimensionalsamplecollectioninwetlands.Thedesignhasbeenusedtoconstructapermanentthree-dimensionalarrayof60-samplelocationsthatcanbesam-pledsimultaneouslythroughouta1.2haconstructedwetlandforlessthanUS$5000.Thesamplingarraywasusedinatracerstudyandshowedspatialandtemporaldifferencesintracerconcentrationwithinthewetland.Concentrationdifferenceswereseenandmea-suredinallthreedimensions.Thebasicfeaturesofthesystemaredescribedandanexamplehowtoconstructanarraythatcansuitanywetlanddesignisgiven.PublishedbyElsevierB.V.1.IntroductionWetlandsofferabiologicallydiverseecosystemcapableofremovingmanycontaminantsfoundinwater.Artificiallyconstructedwetlandsarealow-costtreatmentalternativeforremovalofa