46-Constructed-Wetlands-as-a-Sustainable-Solution-for-Wastewater-Treatment-in-Small-Villages

BiosystemsEngineering(2004)87(1),109–118doi:10.1016/j.biosystemseng.2003.10.005Availableonlineatwww.sciencedirect.comRD}RuralDevelopmentConstructedWetlandsasaSustainableSolutionforWastewaterTreatmentinSmallVillagesM.L.Solano1;P.Soriano1;M.P.Ciria21BiomassProject,RenewableEnergyDepartment,CIEMAT,AvdaComplutense22,Madrid28040,Spain;e-mailofcorrespondingauthor:ml.solano@ciemat.es2CIEMAT-CEDERKm206CarreteraN-111Madrid-Soria,42290Lubia,Soria,Spain;e-mail:pilar.ciria@ciemat.es(Received28May2003;acceptedinrevisedform7October2003;publishedonline20November2003)Withtheaimofsolvingthewastewatertreatmentprobleminsmallvillages,treatmentperformanceofapilot-scalesubsurface-flowconstructedwetland(SFW)wasevaluatedforremovalefficiencyofbiochemicaloxygendemand(BOD),chemicaloxygendemand(COD),totalsuspendedsolids(TSS),totalandfaecalcoliformandfaecalstreptococcibacteriafromrawmunicipalwastewater.Studiesofthecompositionandthermalbehaviouroftheharvestedbiomasswereachievedinordertoassesstheirpossibleutilisationasafuel.Twodifferenthydraulicapplicationrates(150,and75mmday�1)andtwomacrophytes,cattail(Typhasp.)andreed(Phragmitessp.),wereassayed.HighlevelsofBOD,CODandTSSremovalforalltreatmentswereobtained.Thebestremovalswereobtainedinthosebedswiththelowesthydraulicapplicationrate.Withregardtothetypeofplant,nosignificantdifferenceswerefoundbetweencattailandreedperformance;however,cattailsshowedtobebyfar(almostafactorof2)thegreatestproducerofbiomass(22t[d.m.]ha�1).Bothcattailsandreedspresentedhighheatingvalues(17–20MJkg�1).Accordingtotheseresults,itcanbeconcludedthatthewetlandsystemutilisedinthisresearchcouldbeasuitablesolutionforrawwastewaterasastand-alonetreatment,althoughapreviouspre-treatmentinordertoremovegrit,heavysolidsandfloatablematerialswouldbenecessary.Besides,theobtainedbiomasscouldbeutilisedasfuelinasmallboilerfordomesticuses.#2003SilsoeResearchInstitute.AllrightsreservedPublishedbyElsevierLtd1.IntroductionConventionalwastewatertreatmentplantsinvolvelargecapitalinvestmentsandoperating