2015VegetatedFloatingIslandsEnhancetheAbility

See discussions, stats, and author profiles for this publication at: Floating Islands Enhance the Abilityof Wetlands to Reduce Nutrients and OtherPollutantsCONFERENCE PAPER · SEPTEMBER 2015READS211 AUTHOR:Bernie MastersFIA Technology Pty Ltd10 PUBLICATIONS 25 CITATIONS SEE PROFILEAll in-text references underlined in blue are linked to publications on ResearchGate,letting you access and read them immediately.Available from: Bernie MastersRetrieved on: 05 March 2016VegetatedFloatingIslandsEnhancetheAbilityofWetlandstoReduceNutrientsandOtherPollutantsBKMastersFIATechnologyPtyLtdPOBox315,Capel,[e-mail]ructedwetlandshavebeenusedtoimprovewaterqualityinurban,industrialandagriculturalenvironmentsformorethan40years.Initially,pollutantuptakebywetlandplantswasassumedtobetheprimaryremovalmechanismbutresearchnowshowsthatbacterial/algalbiofilmsgrowingonallsolidsurfaceswithinthewatercolumnremovemorethan80%ofpollutants,althoughplantsareneededtotransferoxygenandcarbontobiofilmstomaximisetheirpollutant-removalcapacity.VegetatedfloatingislandsdesignedtomaximisebiofilmdevelopmentwerecommercialisedintheUSAinthemid-2000s.Theirplacementonthesurfaceofwetlandsandotherwaterbodiessignificantlyincreasestheareaofbiofilmcapableofremovingnutrientsandotherpollutants,whilealsoshadingthewatercolumn,reducingwatertemperatureandcreatingusefulwildlifehabitat.Thispapersummarisesthesciencewhichunderpinstheirpollutant-reductionabilitiesandliststhecurrentsuppliersoffloatingislandsinAustralia.IntroductionInthe1980s,whennaturalorconstructedwetlandswerefirstbeingusedinAustraliatoimprovewaterquality,doubtswereexpressedabouttheabilityofwetlandstoreducenutrients,heavymetalsandotherpollutants.Sincethen,researchontheuseofwetlandsforwaterqualityimprovementhasbeenextensive,withdifferentconstructedwetlanddesignsnowavailabletotreatdifferentpollutants.Publishedliteratureonconstructedwetlandsiswidelyavailable;conferencesontheiruseareregularlyheld;andregulatoryauthoritiesnowacceptthatwell-designedwetlandshaveanimportantroletoplayinhelpingtoovercomesomeoftheadverseimpactsofurbanisation,industryandagriculture.Vegetatedfloatingislandswerefirstusedforwaterqualityimprovementinthelate1990s.Thescientificunderstandingofthebiologicalprocessesinvolvedintheirabilitytoremovepollutantsisslowlybutsteadilyimprovingbutacademicandregulatoryacceptanceoftheiruseremainsmodest.Thispaperisdesignedtoshowthat,likewetlands,theuseoffloatingislandsisonasimilarpathwayofunderstandingandacceptance.HistoryofWetlandsandWaterQualityImprovementWetlandsforwaterqualityimprovementappeartohavebeenfirstformallyusedin1971whenalargebiologicalfiltrationsystemwasconstructedinMissouri,USA,totreatacidicwastewaterfromaleadmineandmill(Ertenetal.,1988).Throughthe1970sand1980s,researchersinvestigated2theuseofnaturalwetlandsfordomesticsewagewastewatertreatment(seeBoytetal.1977,TiltonandKadlec1979,Deghietal.1980,DierbergandBrezonik1982).Whilebacteria,algaeandperiphytonwereconsideredtobeimportantinremovingnitrogenfrompollutedwater,quantificationoftheirroleinremovingpollutantswaslargelyabsentfromthescientificliterature,withemphasisgenerallyplacedonplantstakingupmostpollutants.Itwasn’tuntil1988attheFirstInternationalConferenceonConstructedWetlandsforWastewaterTreatmentheldinTennessee,USAthatthescienceunderlyingtheuseofwetlandsforwaterqualityimprovementbegantobeacceptedbyregulatoryauthoritiesandwatermanagers(Hammer1989).HistoryofVegetatedFloatingIslandsandWaterQualityImprovementTheideaofconstructingafloatingplatformonwhichplantscouldbegrowntoimprovewaterqualityoriginatedinChina,JapanandTaiwaninthe1990s.FloatingbedsofCannaCanageneraliswereplacedonfishpondsandtheirbiomassproductionwasmeasured(WuWeiming,etal.2000).Similarsoil-lessfloatingbedsplantedwithCannawerealsousedtocontroleutrophicwater,withcoverageof20%recommendedtosignificantlyimprovewaterquality(BingandChen2001).AvegetatedfloatingislandmadefromlightweightconcretewasusedinKasumigauraLake,Japan,in1998tocreatefishandwaterbirdhabitatwhileimprovingwaterqualityandlandscape(Noriyoshietal.1999)andtoreduceshorelineerosion(Keigoetal.1999).TrialsintheUSAin1987usingthefloatingplantpennywortHydroctyleumbellateimproveddomesticsewagewaterquality(DeBusketal.1989).ManagersofHeathrowAirportinLondon,U.K.,thentrialin1994andinstalledfloatingreedbedstoremoveglycolfromstormwater(Revittetal.1997,Chongetal.1999,Revittetal.2001,Richteretal.2003).CreditmustgotoBruceKaniaofFloatingIslandInternationalLLC(FII)-see(Stewart2005,Stewartetal.2008).Commercialproductionstartedin2005,withthecompanyunderstandingtheimportantroleofmicrobesinnutrientremoval,whilealsorecognisingthat‘microbialremovalrateswerethreetimesgreaterinthepresenceofplantroots’(Hammer1990).FIIrese