ch4 water treatment ii coag
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Water treatment:Water treatment:Water treatment:Water treatment:Water treatment:Water treatment:Water treatment:Water treatment:
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Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.Sudha Goel, Ph.D.
Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Dept. of Civil Eng., IITKgp Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302 Kharagpur 721 302
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Particle sizesParticle sizesParticle sizesParticle sizesParticle sizesParticle sizesParticle sizesParticle sizes
Stable particles that mustStable particles that mustStable particles that mustStable particles that must
be chemically andbe chemically andbe chemically andbe chemically and
2QMZ, 2000
Discrete particles canDiscrete particles canDiscrete particles canDiscrete particles can
be removed bybe removed bybe removed bybe removed by
settlingsettlingsettlingsettling
removalremovalremovalremoval
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Colloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensionsColloids and stable suspensions ColloidsColloidsColloidsColloids: particles that do not settle under the influence of
gravity but remain stable in suspension in a fluid medium
Size range: 1 nm to 1 micron (or even 10 microns) Inorganic particles like asbestos fibers, silt, clay particles
Organic particles: NOM (humic and non-humic substances),viruses bacteria lankton microbes
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Particles in natural watersParticles in natural watersParticles in natural watersParticles in natural waters (generally in pH range of 6 to 8) arenegatively charged
Stable particlesStable particlesStable particlesStable particles: Like charges repel each other and remainsuspended in solution indefinitely
No aggregation is possible due to net repulsive energybetween them
Examples: Silt in rivers, turbidity of lake waters, andground waters
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Coagulation and flocculationCoagulation and flocculationCoagulation and flocculationCoagulation and flocculationCoagulation and flocculationCoagulation and flocculationCoagulation and flocculationCoagulation and flocculation Process for combining small particles (colloids) into larger,Process for combining small particles (colloids) into larger,Process for combining small particles (colloids) into larger,Process for combining small particles (colloids) into larger,
settleable aggregates (flocs)settleable aggregates (flocs)settleable aggregates (flocs)settleable aggregates (flocs) Addition of coagulants like Al or Fe salts, organic polymers to
‘destabilize’ particles so that they will aggregate, form floc and settle Primary objective in water treatmentPrimary objective in water treatmentPrimary objective in water treatmentPrimary objective in water treatment: Removal of turbidity
(particles) and suspended solids (SS) Light is scattered most easily by colloidal suspensions
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oagu a on o ows se men a on an screen ng w ere arger eav er particles or floc are removed by discrete settling
Design objective is removal of colloidal particles (1 nm to 1Design objective is removal of colloidal particles (1 nm to 1Design objective is removal of colloidal particles (1 nm to 1Design objective is removal of colloidal particles (1 nm to 1micron)micron)micron)micron)
Can remove bacteria, soil, sand and clay particles
Concomitant removal of associated compounds or smaller particles like NOM, heavy metals, pesticides, etc. Enhanced coagulation: when an elevated coagulant dose (higher
than the optimum required for turbidity removal) is used to remove
TOC (or NOM) to ensure that DBP conc are not exceeded
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ConcomitantremovalofvariousotherwatercomponentsoccursConcomitantremovalofvariousotherwatercomponentsoccursConcomitantremovalofvariousotherwatercomponentsoccursConcomitantremovalofvariousotherwatercomponentsoccursduringcoagulationduringcoagulationduringcoagulationduringcoagulation NOM:NOM:NOM:NOM: organicmatterofnaturalorigin- canbealgalmaterialorhumicmaterial
Algalmatter: Algalmatter: Algalmatter: Algalmatter: freshOMthathasnotbeenrecycledthro’theCcycle;largelyaliphaticandlowMW
HumicsubstancesHumicsubstancesHumicsubstancesHumicsubstances:derivedfromoldvegetation,complexorganicmatterthatisrelativelyresistanttobiodegradationduetoseveral
CoagulationCoagulationCoagulationCoagulationCoagulationCoagulationCoagulationCoagulation
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recyc est ro t e cyc e; arge yaromat can g PrecursorsfortheformationofDBPsduringchlorination
Color,odorandtaste-impartingcompounds/chemicals
Sequestersheavymetals,responsibleforbacterialregrowth
MicroorganismsMicroorganismsMicroorganismsMicroorganisms
Soil,sandandclayparticlesSoil,sandandclayparticlesSoil,sandandclayparticlesSoil,sandandclayparticles
Toxicsubstances(canbenaturaloranthropogenic)Toxicsubstances(canbenaturaloranthropogenic)Toxicsubstances(canbenaturaloranthropogenic)Toxicsubstances(canbenaturaloranthropogenic) Heavymetals
SOCslikepesticides,andVOCs
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Suspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solidsSuspended versus dissolved solids Distinction between dissolved and suspended solids varies greatly in the
literature.
There are no theoretical cut-offs for these particles
Can only have a cutoff defined based on operational convenience
Choice of filter pore size (anywhere from 1.5 micron to 0.2 micron) isbased on operational requirement or objective.
Colloids fall into either category ‘operationally’ speaking.
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Standard methods Dissolved solids are measured after filtration through glass fiber
filters (no ash residue on burning)
Recommended filters: Whatman 934AH has nominal pore size of 1.5 micron; Millipore AP40 -?
Bacteriological requirements Separation of bacteria from water (especially drinking water
samples) requires much smaller pore sizes
0.2 microns ensures bacterial removal
0.45 microns is often used by researchers
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Coagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and PrecipitationCoagulation, Flocculation and Precipitation
Coagulation:Coagulation:Coagulation:Coagulation: chemical conditioning of particleschemical conditioning of particleschemical conditioning of particleschemical conditioning of particles
Destabilization and change in physicoDestabilization and change in physicoDestabilization and change in physicoDestabilization and change in physico----chemicalchemicalchemicalchemicalproperties of colloidal particlesproperties of colloidal particlesproperties of colloidal particlesproperties of colloidal particles
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Gentle mixing of destabilized suspensions to accelerateGentle mixing of destabilized suspensions to accelerateGentle mixing of destabilized suspensions to accelerateGentle mixing of destabilized suspensions to accelerateinterparticle contact, promoting aggregation and settlinginterparticle contact, promoting aggregation and settlinginterparticle contact, promoting aggregation and settlinginterparticle contact, promoting aggregation and settling
PrecipitationPrecipitationPrecipitationPrecipitation:::: Dissolved minerals (TDS) like Ca, Mg in water can beDissolved minerals (TDS) like Ca, Mg in water can beDissolved minerals (TDS) like Ca, Mg in water can beDissolved minerals (TDS) like Ca, Mg in water can be
precipitated as SS by addition of chemicals like lime andprecipitated as SS by addition of chemicals like lime andprecipitated as SS by addition of chemicals like lime andprecipitated as SS by addition of chemicals like lime andsoda ashsoda ashsoda ashsoda ash
QMZ, 2000
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StericstabilizationStericstabilizationStericstabilizationStericstabilizationStericstabilizationStericstabilizationStericstabilizationStericstabilization
• Adsorptionofpolymersat
solid-waterinterfaces
• hydrophobicand
hydrophilicparts
• quantitativeformulation
difficultunlikeDLmodel• Repulsioncanoccur
duetotwoprocesses
• compression
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• interpenetration• Usedinthemanufactureof
paintsandwaxes
• NOMismainlyhumic
material
• Anionicpolyelectrolytes
• adsorbatinterfaces
• surfaceactive
• contributestoparticle
stabilitybystericeffectsAmirtharajah and O’Melia, 1990
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Colloidal particlesColloidal particlesColloidal particlesColloidal particlesColloidal particlesColloidal particlesColloidal particlesColloidal particles
11Colloidal particles are those that do not settle; they remain in ‘stable’ suspension
QMZ, 2000
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Electric potentialElectric potentialElectric potentialElectric potential
surroundingsurroundingsurroundingsurrounding
particleparticleparticleparticle
Double layer Double layer Double layer Double layer Double layer Double layer Double layer Double layer modelmodelmodelmodelmodelmodelmodelmodel
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Rigid layer attached to particle surfaceRigid layer attached to particle surfaceRigid layer attached to particle surfaceRigid layer attached to particle surface
fixed or Stern layer fixed or Stern layer fixed or Stern layer fixed or Stern layer
Nernst PotentialNernst PotentialNernst PotentialNernst Potential
Zeta PotentialZeta PotentialZeta PotentialZeta Potential
PlanePlanePlanePlane
of of of of shear shear shear shear
Bulk solutionBulk solutionBulk solutionBulk solutionDiffuse layer Diffuse layer Diffuse layer Diffuse layer
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Zeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potentialZeta potential or electrokinetic potential: Potential that
causes charged particles to move towards an oppositely
charged electrode and is associated with the plane of
shear of the fluid around the particles
Double layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer model
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Location of slipping or shear plane is assumed to be theouter border of the Stern layer Stern layer Stern layer Stern layer (Lyklema 1978)
Zeta potentialZeta potentialZeta potentialZeta potentialZeta potentialZeta potentialZeta potentialZeta potential is used to measure particle charge
GouyGouyGouyGouy----Chapman modelChapman modelChapman modelChapman model is a mathematical description of thedouble layer theory
Amirtharajah and O’Melia, 1990
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Double layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer modelDouble layer model Accumulation of counter ions on and around a charged particle results in Accumulation of counter ions on and around a charged particle results in Accumulation of counter ions on and around a charged particle results in Accumulation of counter ions on and around a charged particle results in
two electrical double layerstwo electrical double layerstwo electrical double layerstwo electrical double layers
A fixed, rigid (Stern) layer is formed and remains attached to the particlesurface
Diffuse layer formed due to
Electrostatic attraction and repulsion, resulting in electrical potential
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– , , ……
Thermal and molecular diffusion against conc gradients produced byelectrostatic forces
Van der Waal’s forces – independent of solution composition, f(kindand # of atoms in soln)
Drawbacks of modelDrawbacks of modelDrawbacks of modelDrawbacks of model Ions are treated as point charges, and have no physical or chemical
characteristics
Does not differentiate between coagulants that have the same charge
but different coagulating properties (see Fig 6.6)
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15QMZ, 2000QMZ, 2000QMZ, 2000QMZ, 2000
Double layer Double layer Double layer Double layer Double layer Double layer Double layer Double layer compressioncompressioncompressioncompressioncompressioncompressioncompressioncompression
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16Amirtharajah and O’Melia, 1990
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Increase in solution I results in higher conc of counterions in the diffuseIncrease in solution I results in higher conc of counterions in the diffuseIncrease in solution I results in higher conc of counterions in the diffuseIncrease in solution I results in higher conc of counterions in the diffuse
layer layer layer layer Volume of diffuse layer required to maintain electroneutrality
reduces
Destabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloids
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Example: when freshwater (low I) meets seawater (high I) – particlesin freshwater (silt) get destabilized and settle forming deltas
As double layer gets compressed As double layer gets compressed As double layer gets compressed As double layer gets compressed
Particles can come closer to each other (electrostatic repulsion is
reduced)
VDW forces dominate and net interaction energy becomes attractive
rather than repulsive
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Destabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloidsDestabilization of colloids
ChemicalcoagulantscausedestabilizationofparticlesChemicalcoagulantscausedestabilizationofparticlesChemicalcoagulantscausedestabilizationofparticlesChemicalcoagulantscausedestabilizationofparticles
MechanismsofdestabilizationMechanismsofdestabilizationMechanismsofdestabilizationMechanismsofdestabilization
Compressionofdoublelayerandelectrostaticattraction
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Enmeshmentinprecipitate– sweepflocformation
Adsorptiontopermitinterparticlebridging
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QMZ, 2000
22QMZ, 2000QMZ, 2000QMZ, 2000QMZ, 2000
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Adsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralizationAdsorption and charge neutralization Chargeneutralization(QMZ):Chargeneutralization(QMZ):Chargeneutralization(QMZ):Chargeneutralization(QMZ): AdditionofAlorFesaltsandorganicpolymersprovideshighconcentrationsofcounterionsthatneutralizenegativesurfacechargesonparticles
Netattractiveforcesleadtoaggregation,andsettlingofaggregatesorfloc
ChemicalbondsbetweencolloidandcoagulantcanovershadowESChemicalbondsbetweencolloidandcoagulantcanovershadowESChemicalbondsbetweencolloidandcoagulantcanovershadowESChemicalbondsbetweencolloidandcoagulantcanovershadowESforcesforcesforcesforces
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restabilization)areexamplesofthechemicalinteractionsbetweencolloidsandcoagulants
Destabilizationofparticles(theiraggregation)happensatlowcoagulantconcduetoESforces
Energyinvolvedinelectrostatic(ES)interactionsbetweencolloidandEnergyinvolvedinelectrostatic(ES)interactionsbetweencolloidandEnergyinvolvedinelectrostatic(ES)interactionsbetweencolloidandEnergyinvolvedinelectrostatic(ES)interactionsbetweencolloidand
coagulantioncoagulantioncoagulantioncoagulantion Foramonovalentcounterionandaparticlewithapotentialdifferenceof100mV,theattractiveESenergy=9.6kJ/mol
Comparewithcovalentbondenergiesof200to400kJ/mol
Hbondenergiesof20kJ/mol
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Sweep floc formationSweep floc formationSweep floc formationSweep floc formationSweep floc formationSweep floc formationSweep floc formationSweep floc formation
Precipitationofsaltsathighconcentration
theprecipitate‘sweeps’colloidalparticlesalongwithitselfwhilesettling
Enmeshmentofcolloidalparticlesinprecipitatingcoagulants
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Usedforremovalofturbidity,colorandTOC Forlowturbidityandcolorwaters:solids(coagulantaidslikeactivatedsilica,kaolinite)areaddedalongwithalumtoimprovephysicalflocculationkinetics
Highcoagulantsaltconcwillresultinformationoftherespectivemetalhydroxides
AlorFehydroxides
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Adsorption and Adsorption and Adsorption and Adsorption and Adsorption and Adsorption and Adsorption and Adsorption and
interparticleinterparticleinterparticleinterparticleinterparticleinterparticleinterparticleinterparticle
bridgingbridgingbridgingbridgingbridgingbridgingbridgingbridging
Polymers attach
25PRT 1985PRT 1985PRT 1985PRT 1985
particle leading toaggregation and
floc formation
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Coagulation processCoagulation processCoagulation processCoagulation processCoagulation processCoagulation processCoagulation processCoagulation process1. Coagulantformation
• Al3+ andSO42- ionsformedonadditionofalumarenottheoperativecoagulants
• Resultingpolymericoxyhydroxidespeciesarethecoagulants
• Pre-formedcoagulantsalsoexistlikeactivatedsilica,SOPs,PACl
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(polyaluminumchloride)andPICl(polyironchloride)
2. Particledestabilization
3. Interparticlecollisions
Processes1and2occurinrapid-mixtanks,chemicalconditioningofcolloidstoinduceaggregationofparticlesintosmallfloc
Process3occursbyslowmixingintheflocculationtank;physicalconditioningofsmallaggregatestoformlargeflocthatwillsettle
Amirtharajah and O’Melia, 1990
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27Amirtharajah and O’Melia, 1990
Al, Fe and Si polymeric species and pH reduction on addition of these salts Al, Fe and Si polymeric species and pH reduction on addition of these salts Al, Fe and Si polymeric species and pH reduction on addition of these salts Al, Fe and Si polymeric species and pH reduction on addition of these salts
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28Amirtharajah and O’Melia, 1990
See fig 4.17 (SMP) for Zn and problems for Al and Fe
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29Amirtharajah and O’Melia, 1990 Stumm and Morgan, 1981
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Coagulation practiceCoagulation practiceCoagulation practiceCoagulation practiceCoagulation practiceCoagulation practiceCoagulation practiceCoagulation practice Alum doses are generally in the range of 5 to 50 mg/L Effective from pH of 5 to 7.5 (see solubility diagram)
Ferric chloride Effective from pH 4.5 to 9
Surface waters can be grouped into 4 categories Group 1: high turbidity – low alkalinity
Lowering of pH makes coagulation more effective, but neutralization maybecome necessary
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Group 2: high turbidity – high alkalinity Buffering by alkalinity is adequate for maintaining pH
Adsorption and charge neutralization will be less effective than in lowalkalinity waters
Higher coagulant dose for sweep floc formation
Group 3: low turbidity – high alkalinity Colloid conc is low, therefore adding turbidity causing particles like clay will
improve coagulation (can reduce coagulant dose req.)
Group 4: low turbidity – low alkalinity Additional turbidity or alkalinity has to be added to improve coagulation;
better to add both; direct filtration instead of settling followed by filtration is
another good option (microfloc formation)PRT 1985PRT 1985PRT 1985PRT 1985
PRT 1985PRT 1985PRT 1985PRT 1985
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PRT 1985PRT 1985PRT 1985PRT 1985
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Particle Transport ProcessesParticle Transport ProcessesParticle Transport ProcessesParticle Transport ProcessesParticle Transport ProcessesParticle Transport ProcessesParticle Transport ProcessesParticle Transport Processes Aggregation of destabilized colloids requires flocculation
Flocculation is based on enhancing interparticle collisions
Greater the number of collisions, greater the probability that the particleswill aggregate and floc will be formed
Three physical processes for interparticle collisions to occur 1. Brownian diffusion (perikinetic flocculation)
Random motion of particles due to collision with water molecules
’
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constant and T= abs temp, deg K2. Fluid shear (orthokinetic flocculation)
Driving force is velocity gradient (G) in either laminar or turbulent fluidfields
Gt = design parameter = measure of the relative velocity of twoGt = design parameter = measure of the relative velocity of twoGt = design parameter = measure of the relative velocity of twoGt = design parameter = measure of the relative velocity of two
particles of fluid and the distance between themparticles of fluid and the distance between themparticles of fluid and the distance between themparticles of fluid and the distance between them Gt values range from 104 to 105 for t ranging from 10 to 30 min
3. Differential settling
Vertical transport of particles results in collisions
Driving force is gravity, controlling parameter is settling velocity of particle
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Flocculation or mixingFlocculation or mixingFlocculation or mixingFlocculation or mixing
Rapid mixing: for mixing the coagulant
Detention time is approx. 0.5 min, ideally should be 2 min
Impellers or in line blenders
Conventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatmentConventional drinking water treatment
processes: flocculationprocesses: flocculationprocesses: flocculationprocesses: flocculationprocesses: flocculationprocesses: flocculationprocesses: flocculationprocesses: flocculation
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es va ues: o s- mpe ers an , o , s-
(in line blenders)
Slow mixing: for floc formation
Detention time of approx. 0.5 h
Too fast will break floc; should be slow enough to maximizenumber of particle collisions
Optimum speed has to be determined
QMZ, 2000
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Velocity gradientsVelocity gradientsVelocity gradientsVelocity gradientsVelocity gradientsVelocity gradientsVelocity gradientsVelocity gradients Power dissipation per unit volume (eq 4-14)
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ImpellersImpellersImpellersImpellersImpellersImpellersImpellersImpellers
35PRT 1985PRT 1985PRT 1985PRT 1985
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Design considerationsDesign considerationsDesign considerationsDesign considerationsDesign considerationsDesign considerationsDesign considerationsDesign considerations
Coagulation: determine optimum coagulant dose for
turbidity removal or for turbidity and TOC removal
Flocculation: design of rapid mix and flocculation basins
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clarifiers
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Clariflocculator Clariflocculator Clariflocculator Clariflocculator Clariflocculator Clariflocculator Clariflocculator Clariflocculator
37http://www.environengg.com/clariflocculators.html
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Circular clariflocculator Circular clariflocculator Circular clariflocculator Circular clariflocculator Circular clariflocculator Circular clariflocculator Circular clariflocculator Circular clariflocculator
38Source: Internet(msu)
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Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)
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Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)Plate and tube settlers (M&E)
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LAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIERLAYOUT OF TUBE SETTLERS CLARIFIER
(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)(Gangtok Water Treatment Plant)
42Source: RN Sharma
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TUBE SETTLERSTUBE SETTLERSTUBE SETTLERSTUBE SETTLERSTUBE SETTLERSTUBE SETTLERSTUBE SETTLERSTUBE SETTLERS
43Source: RN Sharma
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COLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIERCOLLECTING CHANNEL OF CLARIFIER
44Source: RN Sharma
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Low DO levels, presence of other Low DO levels, presence of other Low DO levels, presence of other Low DO levels, presence of other
gases, precipitation of minerals likegases, precipitation of minerals likegases, precipitation of minerals likegases, precipitation of minerals like
Fe, As, Mn due to oxidationFe, As, Mn due to oxidationFe, As, Mn due to oxidationFe, As, Mn due to oxidation
Hardness removalHardness removalHardness removalHardness removal
Turbidity, TSS, colloid removal, chlorineTurbidity, TSS, colloid removal, chlorineTurbidity, TSS, colloid removal, chlorineTurbidity, TSS, colloid removal, chlorine
to prevent biological growth on filter to prevent biological growth on filter to prevent biological growth on filter to prevent biological growth on filter
mediamediamediamedia
47Sincero and Sincero, 1996Sincero and Sincero, 1996Sincero and Sincero, 1996Sincero and Sincero, 1996
Pathogen removalPathogen removalPathogen removalPathogen removal
HARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATERHARD GROUNDWATER
Pathogen removalPathogen removalPathogen removalPathogen removal
8/6/2019 Ch4 Water Treatment II Coag
http://slidepdf.com/reader/full/ch4-water-treatment-ii-coag 48/48
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Turbidity, colloid removalTurbidity, colloid removalTurbidity, colloid removalTurbidity, colloid removal
Turbidity, TSS, floc removalTurbidity, TSS, floc removalTurbidity, TSS, floc removalTurbidity, TSS, floc removal
Turbidity, TSS removalTurbidity, TSS removalTurbidity, TSS removalTurbidity, TSS removal
48Sincero and Sincero, 1996Sincero and Sincero, 1996Sincero and Sincero, 1996Sincero and Sincero, 1996
Pathogen removalPathogen removalPathogen removalPathogen removal
TURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATERTURBID SURFACEWATER