ASSESSMENT OF AN INNOVATIVE TECHNOLOGY TO REDUCE

SEDIMENT AND IMPROVE WATER QUALITY IN A STORMWATER POND Laursen,A.1,Ulhaq,S.2,Bostan,V.1andMar9n.D2.1RyersonUniversity.DepartmentofChemistryandBiology.Toronto,Ontario2WCIEnvironmentalSolu9onsInc.OJawa,Ontario.

ABSTRACT WCIEnvironmental Solu9ons Inc., TorontoWater andRyersonUniversitypartnered to complete a12-weekpilotproject to assess changes in sediment andwaterqualityusingWCI’s EOS-2000at the LowerDuckstormwater (SWMP) reten9onpond inHighPark,Toronto.TheEOS-2000operated fromSeptember11,2015 toDecember3,2015.TheEOS-2000 is solar-powered,mobileand requiresno infrastructure.Ryersonmonitoredforonemonthpre-installa9onandthroughouttheproject.Dissolvedoxygen(DO)increasedrapidlyatinstalla9onandstayedabovehistoricalvaluesoverthetreatmentperiod.Oxygensatura9onsurpassed100%.Theoxida9onreduc9onpoten9al(ORP)increasedsharplyatstartandremainedhighandstablethereaZer.Aerobicbacteriacountsincreased1000fold.Waterclarityimprovedby68cm(218%)andchlorophyllareducedby87%.Between14–23cm(7.9%–12.6%)ofsedimentwasdigestedinonly3months.UsingtheEOS-2000withinaSWMPcouldbeaninnova9veandcost-effec9vealterna9vethatiscapableofrejuvena9ng/extendingthelifeofaSWMPby8-12monthsandinthisprojectdemonstrateddredgingcostsavingsof$55,000to$360,000(dependingonclassifica9onofbio-solidsremoved).

INTRODUCTION Redox poten9al (ORP) is an important determinant of biological process-Highredoxpoten9alincreasesefficiencyofcarbonmetabolismDissolvedoxygen(DO)isanimportantcontributortoredoxpoten9al(ORP)-Aerobicrespira9onisthemostefficientpathwayofcarbonmetabolismRelevanceàapondthatsupportshighratesofcarbonmetabolisminsedimentwillaccumulatesedimentmoreslowlyastheorganiccarbonismineralizedtoCO2Technology that increases redox, par9cularly DO, can enhance net respira9on in apondandsloworreversetheaccumula9onofsedimentsGoalàreducethefrequencyofdredgingtherebyreducingmaintenancecosts

OBJECTIVES 1.  DeterminetheeffectoftreatmentbytheEOS-2000onDOandDOsatura9on

2.  DetermineresponsetoincreasedDOandredoxpoten9albyaerobicbacteriainsediments

Ø  Using#ofac9veheterotrophicbacteriaasproxy

3.  Quan9fysedimentdepthover9metodetermineifthereisaresponsetotreatmenti.e.diges9onduetoincreasedaerobicbacteria

4.  Assessesthe9cwaterqualitythroughclarityimprovementusingchlorophyllaandsecchidisc

Pre-installa9on Week1 Week2 Week3 Week4 Week6 Week8 Week12 Sept1 Sept

10Sept17 Sept24 Oct1 Oct8 Oct22 Nov5 Dec3

O2,Temp X Con9nuousfromSept14ORP,pH,cond X X X X X X X X XSecchidepth X X X X X X X X XChlorophyll X X X X X X X XBacterialplatecounts X X X X X X X XNutrients(w&s) X X X X X X X XSedimentmapping X X X XContaminants(sed) X X

RESULTS •  EOS-2000rapidlyincreasedDO(2à8mg/L)andORPaZerinstalla9on;s9mulatedaerobic

respira9oninsediments•  14-23cmofsludgereduc9on

Ø  Ini9aldepth183cm(es9matedvol14,823m3)Ø Es9matedsedimentloss1,175m3–1,863m3(7.9%to12.6%)inonly3months

•  Aerobicbacteriacountincreasedby2-3ordersofmagnitude•  Waterclaritygreatlyimproved(218%)•  Resultofenhancedrespira9onisreduc9onofsedimentorganicmaJer–rollingbackpond

maintenance

Table1:Datacollec.onschedule

Objec.ve4:WaterClarity

Objec.ve3:Sedimentreduc.on

Objec.ve1:DOSatura.on

Objec.ve2:Redoxpoten.alandAerobicbacterialcounts