NOH ASSE BasicsofWaterPurificationSession

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Text of NOH ASSE BasicsofWaterPurificationSession

  • Millipore CorporationBioscience DivisionChristopher YarimaMike Kelly

    Water Purification System for a Laboratory Facility

  • OutlineContaminants in WaterPure Water Applications and Quality StandardsWater Purification Technologies Key Water Purification System Design Steps Systems Questions

  • Water Chemistry Contaminants

  • Ground & Surface Water

  • Contaminants in Potable Water

  • Measurement of Contaminant level

  • Measurement UnitsThickness of a Human hair = 90 micronsSmallest visible particle = 40 microns1 Micron = 10-6 MetersSmallest bacteria = 0.22 micronppm : Parts per Million = mg/Literppb : Parts per Billion = microgram/Literppt : Parts per Trillion = nanogram/Liter

    1 ppb = 1 Second in 32 Years. !!!

  • Water Standards

  • Standards and Common TermsUltrapure/Reagent GradeCritical ApplicationsWater for HPLC,GC, HPLC ,AA , ICP-MS, for buffers and culture media for mammalian cell culture & IVF, reagents for molecular biology...Pure/Analytical GradeStandard ApplicationsBuffers, pH solutions,culture media preparation ,clinical analysers and weatherometers feed.Pure/Laboratory GradeGeneral ApplicationsGlassware rinsing, heating baths, humidifiers and autoclaves filling

    Type 1Type IIType IIIPureUltrapure

  • Laboratory Water Purity SpecificationsConsolidated Guidelines Regulatory Agencies with Published Standards: ASTM: American Society for Testing and Materials CLSI: Clinical and Laboratory Standards Institute(previously NCCLS: National Committee for Clinical Laboratory Standards) CAP: College of American Pathologists ISO: International Organization for Standardization USP: United States Pharmacopoeia EU: European Pharmacopoeia

    Contaminant

    Parameter (units)

    Type 1

    Type 2

    Type 3

    Ions

    Resistivity (M(-cm)

    > 18.0

    > 1.0

    > 0.05

    Silica (ppb)

    < 10

    < 100

    < 1000

    Organics

    TOC (ppb)

    < 20

    < 50

    < 200

    Particles

    particles > 0.2 um (#/ml)

    < 1

    NA

    NA

    Bacteria

    Bacteria (cfu/ml)

    < 1

    < 100

    < 1000

    Endotoxin (EU/ml)

    < 0.001

    NA

    NA

  • ASTM Standards for Laboratory Reagent WaterASTM: American Society for Testing and Materials

    Contaminant

    Parameter (units)

    Type 1

    Type 2

    Type 3

    Ions

    Resistivity (M(-cm)

    > 18.0

    > 1.0

    > 4.0

    Silica (ppb)

    < 3

    < 3

    < 500

    Organics

    TOC (ppb)

    < 100

    < 50

    < 200

    Particles

    particles > 0.2 um (#/ml)

    < 1

    NA

    NA

    Bacteria

    Bacteria (cfu/ml)

    10/1000 ml

    10/100ml

    100/10ml

    Endotoxin (EU/ml)

    < 0.03

    0.25

    NA

  • CLSI*, water quality specifications CLSI guidelines should be read to understand scope and detail for each requirement CLRW; Clinical Laboratory Reagent Water

    SRW; Special Reagent Water CLRW water quality with additional quality parameters and levels defined by the laboratory to meet the requirements of a specific application For example: CLRW quality with low silica and CO2 levels Instrument Feed Water Confirm use of CLRW quality with manufacturer Water quality must meet instrument manufacturers specifications Also defined: Commercially bottled purified water, autoclave and wash water and water supplied by a method manufacturer (use as diluent or reagent)*CLSI: Clinical and Laboratory Standards Institute(previously NCCLS)

    Contaminant

    Parameter (units)

    CLRW

    Ions

    Resistivity (M(-cm)

    > 10.0

    Organics

    TOC (ppb)

    < 500

    Bacteria

    Bacteria (cfu/ml)

  • US and European Pharmacopoeia Pure WaterPurified and Highly Purified Water*USP Purified EU Purified EU Highly PurifiedConductivity:
  • Purification TechnologiesOverview of Key TechnologiesAdvantages/DisadvantagesSummary

  • Purification TechnologiesFiltration Depth and Screen FiltersActivated Carbon and chlorine removalMineral scale control Softening and SequesteringDistillationReverse OsmosisDeionizationElectrodeionizationUltraviolet light

  • Depth & Screen FiltersDepth filters= matrix of randomly oriented fibers in a maze of flow channels.Glass Fiber SEMScreen filters= rigid, uniform continuous mesh of polymeric material with pore size precisely determined during manufacture.Durapore Membrane - SEM2 types of filters: depth & screen (or membrane) filters.Depth filters : for RO protection from fouling (high particle capacity).Membrane filters : for retention of small amounts (quick clogging) of small particulates like bacteria.Additional treatment:Depth filters : for heavily loaded feed water with particles (SDI over specification).Screen filters : for a final low pore size filtration downstream the system.Charge filters : for pyrogen removal, in-line distribution loop

  • Purification TechnologiesFiltration SummaryDepth FiltersRandom StructureNominal retention ratingWorks by entrapment within depths of filter mediaHigh dirt holding capacityScreen/Membrane FiltersUniform StructureAbsolute retention ratingWorks largely by surface sievingLow dirt holding capacity

  • Activated CarbonGranules or beads of carbon activated to create a highly porous structure with very high surface areaActivation can be heat or chemicalPore sizes typically 2000 m2/gramRemoval of organics by adsorptionRemoval of chlorine by adsorption-reduction

  • Mineral Scale ControlCalcium and carbonate ions are common in tap water suppliesScale forms when concentration exceeds solubility limits and CaCO3 precipitates as a solidHigher concentrations increase risk of scale formationHigher pH and higher temperature increase risk of scale formationImportant in domestic water systems and purification technologies

  • Ca++ + 2 Cl-NaRNaRNaRNaR4 Na+ + 4 Cl-CaRRRR"Hard water""Soft water"Cation Exchange ResinMgMg++ + 2 Cl-Scale Control Ion-exchange Softening

  • Cl-NaRNaRNaRNaRMg++ + 2 CL-Ca++ + 2 Cl-EXCESS Na+ Cl-Na+CaMgRRRRSofteners are regenerated using a concentrated brine flushconc. NaClRegenerated resinExhausted resinScale ControlIon-exchange Softener Regeneration

  • Polyphosphate chainScale Control Chemical SequesteringChemical sequestering weakly binds calcium ion preventing calcium and carbonate ions from forming scaleLiquid and solid chemical options availableSolid polyphosphate shown as example illustration

  • Double Distillation Principal BenefitsRemoves wide class of contaminantsBacteria / pyrogen-freeLow capital costLimitationsHigh maintenanceHigh operating costLow resistivityOrganic carryoverLow product flow High waste water flow Water storage

  • Pure WaterSemi-PermeableReverse OsmosisMembraneWaterPlusContaminants Osmotic PressureNatural Osmosis~100 ppm NaCl = 1 psi of osmotic pressure Pure water will pass though the membrane trying to dilute the contaminants

  • PureWaterSemi-PermeableReverse OsmosisMembraneWaterPlusContaminantsReverse OsmosisPressureReject Pressure applied in the reverse direction exceeding the osmotic pressure will force pure water through the membrane A reject line is added to rinse contaminants to drain

  • Reverse Osmosis SummaryBenefitsAll types of contaminants removed: ions, organics - pyrogens, viruses, bacteria, particulates & colloids.Low operating costs due to low energy needs.Minimum maintenance (no strong acid or bases cleaning) Good control of operating parameters.Ideal protection for ion-exchange resin polisher: a large ionic part already removed ( resin lifetime), particulates, organics, colloids also eliminated (no fouling).LimitationsNot enough contaminants removed for Type II water.RO membrane sensitivity to plugging (particulates), fouling (organic,colloids), piercing (particle, chemical attack) and scaling (CaCO3) in the long run if not properly protected.Need of right pressure (5 bars) & right pH for proper ion rejection.Flow fluctuation with pressure and temperature.Membrane sensitivity to back pressurePreservative rinsing neededNeed optimized reject

  • Ion ExchangeBenefitsEffective at removing ions Resistivity 1-10 M.cm with a single pass through the resin bed. Resistivity 18 M.cm with proper pretreatmentEasy to use: Simply open the tap and get waterLow capital costLimitationsLimited or no removal of particles, colloids, organics or microorganismsCapacity related to flow rate and water ionic contentRegeneration needed using strong acid and baseProne to organic foulingMultiple regenerations can result in resin breakdown and water contaminationRisk of organic contamination from previous uses

  • Electrodeionization (EDI, CDI, ELIX, CIX)Continuous deionization technique where mixed bed ion-exchange resins, ion-exchange membranes and a small DC electric current continuously remove ions from water (commercialize by Millipore in mid 80s)Performance enhancements:Ion-exchange added to waste channels improve ion transfer and removal.Conductive beads aded to cathode electrode channel reduces risk of scale and use of a softenerCations driven toward negative electrode by DC currentAnions driven toward positive electrode by DC currentAlternating anion permeable and cation permeable membranes effectively separate ions from waterRO feed water: Avoids plugging, fouling and scaling of the EDI module

  • ElectrodeionizationBenefitVery efficient removal of ions and small MW charged organic (Resitivity > 5 M-cm)Low energy consumptionTypical
  • UV Lamps (254 and 185 nm)UV energy catalyzes production of