higher efficiency in water purification

Benefits:

• Improvingthepurificationprocessbydeterminingthebestdepthtodrawrawwaterfromreservoirs,basedonthequalityofthewatercatchment.

• Positive contribution to consumer health, byreducingtheuseofchemicalproductstoyieldwaterthatismorenaturalandofhigherquality.

• Savingcostsandresourcesbyreducingreagentsandenergy.

• Increasing environmental and socioeconomicsecurity,byreducingwastegenerationandcarbonfootprint.

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Higher Efficiency in Water Purification

“The quality of drinking water will not change, but there will be a change in the efficiency and the amount of reagents used to purify water, which is extremely important in terms of managing and saving resources.”

Francisco Javier FragosoMayorofBadajozSpain

Summary*

Waterqualitydeteriorationrepresentsaseriousenvironmental,economicandsocialproblem.Oneofitsusesistheproduction of drinking water for human consumption,whichhighlightstheimportanceofextractingwaterofthehighestpossiblequalityatthesource,inordertominimisethenecessarypurificationtreatment,saveresources,reducetheenvironmentalimpactandpossibleeffectsonthehealthofconsumerscausedbytheuseofchemicalproductsandtheirderivatives.

Inordertoaddressthesegoals,anautomaticsystemwasproposedtomonitorqualityat reservoirs.Thisprovidesarealtimeassessmentatdifferentdepthlevels,soastoestablishthebestlayerfromwhichtodrawrawwaterandthusoptimiseandsaveondrinkingwatertreatment.

Figure1.TheSantaEngraciaDWTPsuppliesdrinkingwatertoapopulationof300,000 inhabitantsandhasanaverageflowof1,200litrespersecond.

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In2012,Spanishdrinkingwatertreatmentstations(DWTP)provided4,400Hm3ofwatertourbansupplynetworks.Thiswatercamemainlyfromreservoirs.

An analysis of thebehaviour of Spanish reservoirswithnormalstratificationrevealsthatduringthewarmseasonsofspringandsummertherecanbeanobservablethermalanddensityimbalancebetweenthesuperficialandlowerwaterlayersofthereservoir.Duringthesummer,waterbecomedividedintoseparatesections:thesuperficialwaterlayer(epilimnion)andthedeepwaterlayer(hypolimnion),separated by a band of water where the temperaturechangesrapidly(thermocline).Thephysicalandchemicalcharacteristicsofthesethreelayerscanbecompletelydifferentanddependontheinfluxesreceivedbythereservoir– rainwater, fromwastewater treatmentplants,industries,overflowsfromfarmingandagriculturalfields…aswellastheresultsofdraughtseasonsthatnearlyemptythe reservoir or seasons with considerable rainfall thatpracticallyrenewallthecontent.

However,thesituationchangesinautumnandwinter:thedecreaseinambienttemperaturecancausethewaterlayerstomixagainand,therefore,givethemmorehomogeneouscharacteristics.

Followingthenecessarypurificationtreatment(pre-oxidation,coagulationwithaluminiumsalts,decantation,filtration, disinfection…), the DWTP supply the networkwithwaterofnecessaryqualitytobeconsideredasdrinkingwater–asdeterminedbytheRoyalDecree140/2003.

The deterioration of water quality represent a seriousenvironmental, economic and social problem, andhighlights theneedtoextractwater fromsourceswiththehighestpossiblequality.Thisleadstoareductioninthe treatment required,whichsavescostsand reducestheenvironmentalimpactandpossiblehealthconsequencesforconsumersderivedfromtheuseofchemicalproductsandtheirderivatives.

MostofthereservoirsintheIberianPeninsulaarelocatedinareaswithstratifiedreservoirs,thatis,containinglayersofvaryingqualities.Therefore, thecostsderivedfrom the purification treatment are determined by thecharacterisationofwatermasses,makingitcrucialtodefinetheoptimalextractionpoint.

“Goal: Optimise the current purification processes through an advanced monitoring system capable of identifying the ideal point of extraction in a reservoir, determining the dosage of reagents and guaranteeing drinking water quality.”

“The costs derived from purification treatments are determined by the characterisation of water masses, making it crucial to define the optimal extraction point.”

TraditionalreservoirmanagementtookwaterdestinedforaDWTPfromaspecificandfixeddepth,eitherbecausethewaterqualityatdifferentdepthswasunknown,orbecausethetechnicalfacilitiestoextractwateratvaryingdepthsarenotavailable.

Figure 2. Drinking water treatment plant at Santa Engracia(Badajoz).

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Higher Efficiency in Water Purification

Thankstothisinformation,managedthroughasystemtosupportdecision-makingbasedonanumericalmodel,itispossibletodeterminethewaterextractionpointwiththe lowestwater treatment costs and define the idealdepth to extract rawwater. This combination improvesthepurificationprocessintermsofeconomiccost(chemicalproducts and energy) and public health (reduction ofchemicalproductdosage),andalsoincreaseswaterqualityandreliabilityatalowercost.

“Higher quality at the source, lower cost of purification treatment.”

ThissystemcanmonitortheDWTPprocessfromanyremotelocationandenablesoperatorstointeractandplantasksinanysituation,inanoptimalandeffectivemanner.

Figure 3. Evolution of thewater quality level at Villar delReyReservoir(Badajoz).

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Figure 4. Comparison of purification costs for rawwater fromdifferentsourcesinExtremadura(2007-2013period).

InthewordsofÁngelEncinas,researcherinchargeoftheprojectatAqualia,“thankstothemonitoringofpurificationprocessandattheplantoutput,wehaveachievedabetter control. Obtaining instantaneous informationaboutwaterqualityinthereservoirandtheplantallowsustoactfaster,createalertsand,therefore,complywiththelaw,justaswehavebeendoingsofar,butwithgreatercontrol”.

Moreover,theMayorofBadajoz,FranciscoJavierFragoso,declared “thisprojectwillmake itpossible toknow thecharacteristicsofthewaterextractedfromthereservoir.This, inturn,will facilitateamoreefficientmanagementofpublic resources forwaterpurification, aswewill nolongerdependonconstantlaboratoryanalysessincewewillhaveautomaticparameters”.

“The project has facilitated a more efficient management of public resources for water purification.” FranciscoJavierFragoso,MayorofBadajoz.

Under this premise, the key aim of the Smartic project(SmartTechnologyRealTimeWaterMonitoringSystem)is to optimise current purification processes using anadvanced control system capable of selecting the bestextraction point in a reservoir, as well as automaticallydeterminingthedosesofmainreagentsandmonitoringwaterevolutionthroughoutthetreatmentprocess,guaranteeingitsqualityforconsumption.

Tothisend,theautomaticqualitymonitoringsystemhasbeen installed in the reservoir of Villar del Rey, whichprovideswatertothedrinkingwatertreatmentplantofSantaEngracia,inBadajoz.Thissystem,whichevaluatesqualityinrealtimeandatvaryinglevels,combinedwithan adjustable installation to extract water at differentdepths,allowsfortheselectionofwaterlayerswiththemostsuitablecharacteristics.

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Higher Efficiency in Water Purification

Figure 5. Technician verifying the values obtained by theautomaticwaterqualitysystemfordifferentreservoirlayers.

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About Adasa

Foundedin1988,Adasaisarecognisedengineeringcompanythat offers advanced water quality monitoring solutions.Weunderstandtheneedsofwaterandwastewaterapplicationsandhaveprovencapabilitiesinallfacetsofdesign,manufacturingandmaintenanceofmajorcontrolsystems,communication,monitoringequipmentandapplicationsoftware.

Adasaproductsandsolutionscanhelpyouto:detectpollution alerts and uncontrolled spills, improve WWTPprocessefficiencybymakingtreatmentdecisionsbasedonrealtimewaterqualityconditions,makeinformeddecisionsinwaterdischarges,protectthedrinkingwatertreatmentplantscatchmentsandunderstandthedynamicofreservoir,damsanddepositsofwater,allowingmanagementresolutionsdependingonenduseanddemand(fishlife,bathingwater,drinkingwater,irrigation...).

Inaddition,anenvironmentalandsocioeconomicimpactstudyhasconcludedthat theapplicationof thissystemrepresents an improvement, from the extraction of rawwater fromthe reservoir, to theapplicationof themainchemical reagentsemployed in thepurificationprocess.This improvement in quality and lower use of reagentstranslates into a reduction of thewaste generated andhigherenvironmentalquality,aswellasasmallercarbonfootprintgeneratedbytheoverallprocess.Asaresult,theenvironmentalandsocioeconomicsafetyandhealthhavebeenincreasedthroughtheconsumptionofmorenaturalandhigherqualitywater.

“The higherwater quality extracted at the source, thelower the need for purification treatment”, explainedFragoso,addingthat“thequalityofthedrinkingwaterwillnotchange,buttherewillbeachangeintheefficiencyandtheamountofreagentsusedtopurifywater,whichisextremelyimportantintermsofmanagingandsavingresources”.

A comparative study conductedbetween theDWTPofÁvilaandLangreodeterminedthattreatingoptimalrawwater can reduce the consumption of energy by up to51%,chlorineby45%andcoagulantsby68%.Theseresultsalsotranslateintolessresidueandareductionofgreenhousegasemissionsfrompoweruseandtheproductionofchlorineandcoagulants.

“This improvement in quality and reduced use of reagents translates into reduction of residue generation and higher environmental quality.”

*This project has been developed by a consortium formed by Adasa, Aqualia, Coveless Ingeniería, Homeria Open Solutions, Enmusa and Gestiona Global.

Source: INE: http://www.ine.es/prensa/np872.pdf

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Higher Efficiency in Water Purification