This document discusses water treatment processes for rivers and waste water. It covers pre-treatment of river water which includes chlorination, clarification, and filtration to produce good quality demineralized water. Clarification removes suspended solids through coagulation, flocculation, and settling. Proper pre-treatment is important to prevent ion exchange resins from fouling during demineralization. The document also discusses properties of water like turbidity, color, conductivity, pH, and alkalinity and how impurities like dissolved and suspended solids are removed.

1. Water TreatmentWater Treatment
Prepared by:Prepared by:
Md. Abdul HannanMd. Abdul Hannan
Plant Chemist,Plant Chemist,
MPL.MPL.
15th September,15th September,
2013.2013.

2. River & WasteRiver & Waste
Water TreatmentWater Treatment
• Water can dissolve every naturally occurring substance on theWater can dissolve every naturally occurring substance on the
earth and so it is called ‘universal solvent'. In power plant -earth and so it is called ‘universal solvent'. In power plant -
water need to treat to remove the impurities & to getwater need to treat to remove the impurities & to get
optimum condition for operation. Treatment started from riveroptimum condition for operation. Treatment started from river
water and finished at waste water.water and finished at waste water.
• Good pretreatment of river water is required to produceGood pretreatment of river water is required to produce
good quality of demineralized water and goodgood quality of demineralized water and good
demineralized water quality is essential to ensuredemineralized water quality is essential to ensure
satisfactory boiler water treatment performance tosatisfactory boiler water treatment performance to
produce pure steam with minimize corrosion & scaleproduce pure steam with minimize corrosion & scale
formation.formation.
• To achieve optimum efficiency of HRSG, water qualityTo achieve optimum efficiency of HRSG, water quality
and steam purity are important.and steam purity are important.

3. Properties of WaterProperties of Water
Turbidity & ColorTurbidity & Color
• TurbidityTurbidity -- Turbidity is the cloudiness or haziness of theTurbidity is the cloudiness or haziness of the
water caused bywater caused by suspended solids(silt, organic matters,suspended solids(silt, organic matters,
precipitated salts).precipitated salts).
• ColorColor – Caused by suspended solids and dissolved solids– Caused by suspended solids and dissolved solids

4. ConductivityConductivity
• The ability of water to pass electric current or theThe ability of water to pass electric current or the
amount of electricity can carry the ions in the wateramount of electricity can carry the ions in the water
• Expressed asExpressed as µµS/cm or mmohsS/cm or mmohs
• Depend on the movement of ions (thus concentration) inDepend on the movement of ions (thus concentration) in
solutionsolution
• Often correlated to Total Dissolved Solids (TDS)Often correlated to Total Dissolved Solids (TDS)
• Typically TDS is 0.50 times of conductivity for high TDSTypically TDS is 0.50 times of conductivity for high TDS
(>1500 micromohs) and 0.65 for low TDS(>1500 micromohs) and 0.65 for low TDS

5. pHpH
• pH denotes as the potential of hydrogen ion concentrationpH denotes as the potential of hydrogen ion concentration
• So, it is a measure of hydrogen ion concentrationSo, it is a measure of hydrogen ion concentration
• pH = -logpH = -log1010[H[H++
]]
– high pH = low Hhigh pH = low H++
concentrationconcentration
– low pH = high Hlow pH = high H++
concentrationconcentration
– 1 unit change in pH signifies factor of 10 change in H1 unit change in pH signifies factor of 10 change in H++
concentrationconcentration
For water:For water:
In water concentration ofIn water concentration of HH++
is 10is 10-7-7
moles/L.moles/L.
So , pH of water = -logSo , pH of water = -log1010[H[H++
] = -log] = -log1010[10[10-7-7
] = 7] = 7

6. AlkalinityAlkalinity
• Alkalinity isAlkalinity is the measure of the overall quantitative capacitythe measure of the overall quantitative capacity
of a substance to neutralize an acid.of a substance to neutralize an acid.
• In most raw waters, alkalinity is caused by OHIn most raw waters, alkalinity is caused by OH--
, HCO, HCO33
--
, CO, CO33
2-2-
,,
BOBO33
3-3-
,PO,PO44
3-3-
,SiO,SiO44
4-4-
,NO,NO33
--
,S,S22
--
,dissolved ammonia and the conjugate,dissolved ammonia and the conjugate
bases of some organic acids .bases of some organic acids .

7. Buffering capacityBuffering capacity
• Buffering capacity – is the ability of a solution to resist pHBuffering capacity – is the ability of a solution to resist pH
changeschanges
• Buffer solution – is a solution used to prevent changes in pH.Buffer solution – is a solution used to prevent changes in pH.
– Preparation of buffer solutionsPreparation of buffer solutions - normally prepared by- normally prepared by
(i) Solution of acid and its salt solution for lower pH range(i) Solution of acid and its salt solution for lower pH range
(ii) Solution of base and its salt for higher pH buffer.(ii) Solution of base and its salt for higher pH buffer.

8. Impurities found in WaterImpurities found in Water
CategoriesCategories
.Undissolved Solids:.Undissolved Solids:
a. Suspended Solids(silt, organic matters, precipitated salts).a. Suspended Solids(silt, organic matters, precipitated salts).
b. Colloidal Substances.b. Colloidal Substances.
c. Organics:c. Organics:
-Living micro-organisms( bacteria, algae etc.).-Living micro-organisms( bacteria, algae etc.).
- Vegetation- Vegetation
.Dissolved solids.Dissolved solids
aa.. Inorganic :(i)Inorganic :(i)Mineral salts:Mineral salts: ((CaCOCaCO33 , Ca(HCO, Ca(HCO33))22 , Mg (HCO, Mg (HCO33))22 NaCl, KCl,NaCl, KCl,
NaNONaNO33 CaClCaCl22, Na, Na22SOSO44 etc.etc. ))
(ii)(ii)Silica(SiOSilica(SiO22) :) : Silicic acid (HSilicic acid (H44SiOSiO44 or Hor H22SiOSiO33), Hydrated non-), Hydrated non-

9. Ions present in dissolved solidsIons present in dissolved solids
• CationsCations -- Ions that carry net positive charges e.g. Sodium (NaIons that carry net positive charges e.g. Sodium (Na++
),),
Potassium (KPotassium (K++
), Calcium (Ca), Calcium (Ca2+2+
), Magnesium (Mg), Magnesium (Mg2+2+
), Iron (Fe), Iron (Fe2+2+
,Fe,Fe3+3+
), ),), ),
Aluminium (AlAluminium (Al3+3+
),Manganese (Mn),Manganese (Mn2+2+
, Mn, Mn4+4+
)etc.)etc.
• AnionsAnions -- Ions that carry net negative charges e.g. BicarbonatesIons that carry net negative charges e.g. Bicarbonates
(HCO(HCO33
--
), Phosphate (PO), Phosphate (PO44
3-3-
),Carbonates (CO),Carbonates (CO33
2-2-
), Borate ( BO), Borate ( BO33
3-3-
), Sulfide), Sulfide
(S(S22
--
), Sulfates (SO), Sulfates (SO44
2-2-
), Silicate(), Silicate(SiOSiO33
2-2-
,,SiOSiO44
4-4-
) ,Nitrates (NO) ,Nitrates (NO33
--
), Chlorides), Chlorides
(Cl(Cl--
), Oxides (O), Oxides (O2-2-
), Hydroxides (OH), Hydroxides (OH--
) etc.) etc.

10. Dissolved Solids Commonly Found in WaterDissolved Solids Commonly Found in Water
Calcium
Magnesium
Sodium
Silicon
Iron
Bicarbonate
Sulfate
Chloride
Bicarbonate
Sulfate
Chloride
Bicarbonate
Sulfate
Chloride
Oxide
Bicarbonate
Hydroxide
Sulfate
Ca(HCO3)2
CaSO4
CaCl2
Mg(HCO3)2
MgSO4
MgCl2
NaHCO3
Na2SO4
NaCl
SiO2
Fe(HCO )
CompoundAnionCation

11. Classification & Properties ofClassification & Properties of
SilicaSilica
3 different types3 different types
• Soluble (also known as reactive)Soluble (also known as reactive)
• InsolubleInsoluble
– Amorphous (also known as inert)Amorphous (also known as inert)
– Colloidal (also known as non-reactive)Colloidal (also known as non-reactive)

12. Soluble SilicaSoluble Silica
MonomericMonomeric
• Molybdate reactive Silica (HMolybdate reactive Silica (H44SiOSiO44 or Hor H22SiOSiO33), Hydrated, non-), Hydrated, non-
ionized species (SiOionized species (SiO22xHxH22O)O)
• Can react with cations to form insoluble silicatesCan react with cations to form insoluble silicates
• Can polymerize to form inert amorphous silicaCan polymerize to form inert amorphous silica

13. Insoluble SilicaInsoluble Silica
AmorphousAmorphous
• Inert SiOInert SiO22 (Quartz) sand particles(Quartz) sand particles
• Settles outSettles out
• Visible to the eyeVisible to the eye
• Can be filtered out with a 0.2 micron filterCan be filtered out with a 0.2 micron filter
• Appears as suspended solids in the analysisAppears as suspended solids in the analysis

14. Insoluble SilicaInsoluble Silica
ColloidalColloidal
• The colloidal silica are polymerized (dimmer or higherThe colloidal silica are polymerized (dimmer or higher
forms) and is not react with molybdate but when heated in aforms) and is not react with molybdate but when heated in a
boiler reverts to the basic silicate monomer, which is reactiveboiler reverts to the basic silicate monomer, which is reactive
with molybdate.with molybdate.
• Remains dispersed or suspendedRemains dispersed or suspended
• Smaller than 0.2 micronsSmaller than 0.2 microns
• Does not appear as suspended solids in analysisDoes not appear as suspended solids in analysis

15. Concentration UnitsConcentration Units
ConcentrationConcentration
–units of solute per unit of solventunits of solute per unit of solvent
( ppm, ppb, ppt, mg/L, µg/L, µg/ml, % etc.)( ppm, ppb, ppt, mg/L, µg/L, µg/ml, % etc.)
–ppmppm (parts per million)(parts per million)
• No, of parts of solute per million parts of solventNo, of parts of solute per million parts of solvent
• 0.001 grams/1000 grams0.001 grams/1000 grams
= 0.001g solute/1000 g solvent= 0.001g solute/1000 g solvent
= 1 g solute/1,000,000 g solvent= 1 g solute/1,000,000 g solvent
= 1 ppm= 1 ppm
• ppm = mg/L=µg/ml=mg/kg=µg/g for water.ppm = mg/L=µg/ml=mg/kg=µg/g for water.
• 1 % = 101 % = 1044
ppmppm
–mg/L does not = mg/kg or mL/L unless S.G. = 1.0mg/L does not = mg/kg or mL/L unless S.G. = 1.0

16. Relations between some unitsRelations between some units
• 10,000 ppm = 1% (W/V or W/W).10,000 ppm = 1% (W/V or W/W).
• 100,000 ppm = 10% (W/V or W/W).100,000 ppm = 10% (W/V or W/W).
• 1 m1 m33
of water = 1000 L = 1000 kg (S.G. of water = 1.0)of water = 1000 L = 1000 kg (S.G. of water = 1.0)
• Therefore 1 ppm = 1g / mTherefore 1 ppm = 1g / m33
or 1 kg / 1000 mor 1 kg / 1000 m33

17. Factors Affecting SolubilityFactors Affecting Solubility
• TemperatureTemperature -- Most salt’s solubility increases withMost salt’s solubility increases with
increasing temperature (Exception: CaSoincreasing temperature (Exception: CaSo44,MgCl,MgCl22 ,Na,Na33POPO44 etc.)etc.)
• AlkalinityAlkalinity -- Most salt’s solubilities increases with decreasingMost salt’s solubilities increases with decreasing
alkalinity (Exception: Silica)alkalinity (Exception: Silica)
• pHpH -- Most salt’s solubility increases as the pH dropsMost salt’s solubility increases as the pH drops
(Exception: Silica)(Exception: Silica)
• Oxidation stateOxidation state -- Most salt’s solubility increases withMost salt’s solubility increases with
decreasing oxidation statedecreasing oxidation state

18. Treatment proceduresTreatment procedures
Different kinds:Different kinds:
• Pretreatment: Influent Chlorination, clarification & filtration of rawPretreatment: Influent Chlorination, clarification & filtration of raw
water.water.
• Treatment:Treatment:
– Reverse OsmosisReverse Osmosis
– Thermal DesalinationThermal Desalination
– Demineralization: Ion exchange resin methodDemineralization: Ion exchange resin method
– Ozone/Ultraviolet treatment etc.Ozone/Ultraviolet treatment etc.

19. Chlorine injection in coolingChlorine injection in cooling
water intakewater intake

20. Chlorine injection in coolingChlorine injection in cooling
water intakewater intake

21. Unused free chlorine gasUnused free chlorine gas
neutralization systemneutralization system

22. Pre treatmentPre treatment
Consist of 3 steps:Consist of 3 steps:
• 1. Chlorination:1. Chlorination: in river water by liquid Chlorine /Sodiumin river water by liquid Chlorine /Sodium
hypochlorite.hypochlorite.
ClCl22 + H+ H22OO  HOCl + HClHOCl + HCl
NaOCl + HNaOCl + H22OO  HOCl + NaOHHOCl + NaOH
• 2. Clarification:2. Clarification: in clarifier by alum & polyelectrolyte.in clarifier by alum & polyelectrolyte.

23. ClarificationClarification
Fast mix -- CoagulationFast mix -- Coagulation
Slow mix -- FlocculationSlow mix -- Flocculation
SettlingSettling
Mixing time of different stages :Mixing time of different stages :
Mixing EnergyMixing Energy DetentionDetention
(G=sec(G=sec-1-1
)) Time (min)Time (min)
Coagulation (Rapid Mix)Coagulation (Rapid Mix) 300-500300-500 0.5-30.5-3
Flocculation (Slow Mix)Flocculation (Slow Mix) 30-9030-90 20-4020-40
SettlingSettling 00 120-240120-240

24. Effect of upset clarifier onEffect of upset clarifier on
Water QualityWater Quality
Clarifier and Pressure filter are the main parts of the pretreatmentClarifier and Pressure filter are the main parts of the pretreatment
plant which remove coarse-dispersed & colloidal impurities, organicplant which remove coarse-dispersed & colloidal impurities, organic
substances and other non-dissolved suspended particles from thesubstances and other non-dissolved suspended particles from the
water. When Clarifier upset and or Presser filter cannot workwater. When Clarifier upset and or Presser filter cannot work
properly for any reason, these solid impurities and organic substancesproperly for any reason, these solid impurities and organic substances
enter into demineralizing plant resulting exhaustion of Ion exchangeenter into demineralizing plant resulting exhaustion of Ion exchange
resin with clay & sludge and consequent fouling such as silicaresin with clay & sludge and consequent fouling such as silica
fouling, organic fouling etc. So special attention should be given tofouling, organic fouling etc. So special attention should be given to
proper operation of the pretreatment plant. Activated carbon filterproper operation of the pretreatment plant. Activated carbon filter
removes residual free chlorine (produced from sodium hypochloriteremoves residual free chlorine (produced from sodium hypochlorite
which doze in clarifier’s inlet to destroy the living organisms) andwhich doze in clarifier’s inlet to destroy the living organisms) and
organic matter.organic matter.

25. CoagulantsCoagulants
Coagulants may be Inorganic and organic.Coagulants may be Inorganic and organic.
Inorganic Coagulants:Inorganic Coagulants:
• React through hydrolysis withReact through hydrolysis with
available alkalinityavailable alkalinity
• Form precipitate of insoluble hydroxide andForm precipitate of insoluble hydroxide and
hydroxyl complexeshydroxyl complexes
• Generally requires caustic to neutralizeGenerally requires caustic to neutralize
• Alum, Ferric chloride and Sulfate, Ferrous Sulfate etc.Alum, Ferric chloride and Sulfate, Ferrous Sulfate etc.

26. Favorable Coagulants at diff.Favorable Coagulants at diff. pHpH
NameName FormulaFormula pH RangepH Range
Alum (Aluminum AlAlum (Aluminum Al22(SO(SO44))33 . 18H. 18H22OO 5.5 - 7.55.5 - 7.5
Sulfate)Sulfate)
Sodium Aluminate NaAlOSodium Aluminate NaAlO22, Na, Na22AlAl22OO44 or 5.5 - 11or 5.5 - 11
(liquid)(liquid) NaNa22O * AlO * Al22OO33
PACPAC AlOAlO44AlAl1212(OH)(OH)2424(H(H22O)O)1212
+7+7
4.0 - 9.0 (liquid)4.0 - 9.0 (liquid)
Ferrous SulfateFerrous Sulfate FeSOFeSO44 * 7H* 7H22OO 8 - 118 - 11
Ferric SulfateFerric Sulfate FeFe22(SO(SO44))33 * 2H* 2H22O or 5 - 11O or 5 - 11

27. Clarifier ControlClarifier Control
As the Meghna river water contains a very low level of turbidityAs the Meghna river water contains a very low level of turbidity
(6 – 50 NTU), Clarifier coagulation is very difficult as the less(6 – 50 NTU), Clarifier coagulation is very difficult as the less
availability of non-dissolved particles for coagulation and henceavailability of non-dissolved particles for coagulation and hence
alum dozing should be maintained in a level as less as possiblealum dozing should be maintained in a level as less as possible
due to excess alum dozing may carry over excess free trivalentdue to excess alum dozing may carry over excess free trivalent
aluminum ion and sulfate ion from clarifier and then give load onaluminum ion and sulfate ion from clarifier and then give load on
resin exchangers, exhaust the cation resin by the excessresin exchangers, exhaust the cation resin by the excess
free trivalent aluminum ions and the anion resin by the excessfree trivalent aluminum ions and the anion resin by the excess
sulfate ion.sulfate ion.
Dozing of Sodium Hydroxide in clarifier to adjust pH should alsoDozing of Sodium Hydroxide in clarifier to adjust pH should also
be minimized if possible avoided in order to keep the ionic loadbe minimized if possible avoided in order to keep the ionic load
in the process water at a desired level.in the process water at a desired level.

28. Objectives of ClarificationObjectives of Clarification
• Suspended Solids (Insolubles) RemovalSuspended Solids (Insolubles) Removal
• Colour (colloidal) RemovalColour (colloidal) Removal
• Microbiological ControlMicrobiological Control

29. Fe and Mn RemovalFe and Mn Removal
Strong chemical oxidants such as OStrong chemical oxidants such as O22, Cl, Cl22 ,NaOCl or KMnO,NaOCl or KMnO44
may be used for oxidation of soluble Femay be used for oxidation of soluble Fe2+2+
& Mn& Mn2+2+
salts tosalts to
insoluble Feinsoluble Fe3+3+
hydroxide & Mnhydroxide & Mn4+4+
oxide.oxide.
4Fe(HCO4Fe(HCO33))22 + O+ O22 + 2H+ 2H22O = 4Fe(OH)O = 4Fe(OH)33↓ + 8CO↓ + 8CO22↑↑
2Mn(HCO2Mn(HCO33))22 + O+ O22 = 2MnO= 2MnO22↓ + 4CO↓ + 4CO22↑ + 2H↑ + 2H22OO

30. CoagulationCoagulation
Inorganic salts neutralize the charge with the raw waterInorganic salts neutralize the charge with the raw water
turbidity(particles) and also hydrolyze to form insolubleturbidity(particles) and also hydrolyze to form insoluble
precipitates, which entrap particles.precipitates, which entrap particles.
AlAl22(SO(SO44))33 + 6NaHCO+ 6NaHCO33 = 2Al(OH)= 2Al(OH)33↓ + 3Na↓ + 3Na22SOSO44 + 6CO+ 6CO22
NaNa22AlAl22OO44 + 4H+ 4H22O = 2Al(OH)O = 2Al(OH)33↓ + 2NaOH↓ + 2NaOH
FeFe22(SO4)(SO4)33 + 6NaHCO+ 6NaHCO33 = 2Fe(OH)= 2Fe(OH)33↓ + 3Na↓ + 3Na22SOSO44 + 6CO+ 6CO22
Agitation increase the effective number of collisions andAgitation increase the effective number of collisions and
enhance cation adsorption onto suspended solids.enhance cation adsorption onto suspended solids.

31. H2OH2O
AlAl22(SO(SO44))33 -------- 2Al2Al3+3+
+ SO+ SO44
2-2-

32. AlAl22(SO(SO44) + H) + H22O ---O --- Al(OH)Al(OH)3↓3↓ + H+ H22SOSO44

33. Effect of CoagulationEffect of Coagulation

34. FlocculationFlocculation
The agglomeration of destabilized particles into largeThe agglomeration of destabilized particles into large
particles by charge site binding and molecularparticles by charge site binding and molecular
bridging through the addition of high molecularbridging through the addition of high molecular
weight water soluble charged organic polymers.weight water soluble charged organic polymers.
i.e. slow mix and bridging of coagulated particles.i.e. slow mix and bridging of coagulated particles.

35. Flocculation - BridgingFlocculation - Bridging

36. Stokes LawStokes Law
• The Bigger and Heavier they are the Faster they Fall”The Bigger and Heavier they are the Faster they Fall”

37. Particle Settling Velocities at 10Particle Settling Velocities at 10oo
CC
Diameter ofDiameter of Order ofOrder of Time RequiredTime Required
Particle in mmParticle in mm MagnitudeMagnitude
10.010.0 GravelGravel 0.3 seconds0.3 seconds
1.01.0 Coarse SandCoarse Sand 3 seconds3 seconds
0.10.1 Fine SandFine Sand 38 seconds38 seconds
0.010.01 SiltSilt 33 minutes33 minutes
0.0010.001 BacteriaBacteria 35 hours35 hours
0.00010.0001 Clay ParticlesClay Particles 230 days230 days

38. Dilution Constant of CoagulantDilution Constant of Coagulant
DDkk = (C= (Ckk× Q× QDpDp)/ Q)/ QCaCa
Where,Where,
CCkk = Coagulant concentration meq/l= Coagulant concentration meq/l
QQDpDp = Coagulant dosing pump flow rate litre/h= Coagulant dosing pump flow rate litre/h
QQCalCal = Flow of Raw water into the Clarifier m= Flow of Raw water into the Clarifier m33
/h/h
DDkk Value shouldbe0.2~0.3meq/lValue shouldbe0.2~0.3meq/l

39. Infilco AccelatorInfilco Accelator
(Solids-Contact Type)(Solids-Contact Type)
Chemical Chemical
Effluent
Clarified Water
Secondary Mixing
and Reaction Zone
Clear Water
Escape Surface
Return Flow
ZoneConcentrator
Discharge
Blow-Off and Drain Slurry Pool Indicated by Shaded Areas
Primary Mixing and Reaction Zone
Draft Tubes
Hood
Raw
Water
Rotor-Impeller

41. WATERUSERS
Pretreatment
BOILERS, COOLING
SYSTEMS, PROCESSES
SecondaryPrimary
INFLUENT
SLUDGE CAKE
R
I
V
E
R

42. Clarifier CarryoverClarifier Carryover
• Clarifier upsets can result in floc carrying over in the clarified waterClarifier upsets can result in floc carrying over in the clarified water
• Potential for clarified water to contain large amounts of aluminium orPotential for clarified water to contain large amounts of aluminium or
iron if inorganic coagulants are usediron if inorganic coagulants are used
• Fouling potential in downstream systemsFouling potential in downstream systems
• Normal practice to have a filter after the clarifier to removeNormal practice to have a filter after the clarifier to remove
downstream impact of floc carryoverdownstream impact of floc carryover

43. Classification of FiltersClassification of Filters
Slow or RapidSlow or Rapid
Gravity or PressureGravity or Pressure
Type of MediaType of Media
- Sand / Anthracite / Multi-media- Sand / Anthracite / Multi-media
Flow DirectionFlow Direction

44. Pressure type Sand FilterPressure type Sand Filter

45. By applying Jar Test ,pH or M-Alkalinity test and DBy applying Jar Test ,pH or M-Alkalinity test and DKK value we canvalue we can
control the dozing rate in clarifier and hence clarified watercontrol the dozing rate in clarifier and hence clarified water
turbidity.turbidity.
**The conductivity difference of Reaction zone & River water**The conductivity difference of Reaction zone & River water
should be -10 to +20 or 30 µS/cm. Sometimes it found more than 100should be -10 to +20 or 30 µS/cm. Sometimes it found more than 100
µS/cm which led to increase the conductivity of demi water as well asµS/cm which led to increase the conductivity of demi water as well as
the Boiler/HRSG system.the Boiler/HRSG system.
So, we should try to maintain the con. diff. as low as possible.So, we should try to maintain the con. diff. as low as possible.
*Click the arrow to see analysis reports*Click the arrow to see analysis reports
Jar test analysis
report.xls

46. Removal of Free ClRemoval of Free Cl22
• Free Chlorine produced from Sodium Hypochlorite which isFree Chlorine produced from Sodium Hypochlorite which is
dosed in the clarifier inlet water, should be removed before waterdosed in the clarifier inlet water, should be removed before water
under go to the Resin exchanger.under go to the Resin exchanger.
• So, after Pressure filter water must be pass through ActivatedSo, after Pressure filter water must be pass through Activated
Carbon filter to remove free chlorine. Otherwise degradation ofCarbon filter to remove free chlorine. Otherwise degradation of
resin in cation exchanger and then consequent fouling in theresin in cation exchanger and then consequent fouling in the
anion exchanger can be occurred.anion exchanger can be occurred.

47. TreatmentTreatment
Ion Exchange Resin methodIon Exchange Resin method
• After passing through the pressure and activated carbon filterAfter passing through the pressure and activated carbon filter
clear water is first passed through hydrogen cation-exchangeclear water is first passed through hydrogen cation-exchange
units which exchange all cations (Alunits which exchange all cations (Al++++++
, Fe, Fe++++++
,Ca,Ca++++
, Mg, Mg++++
, Na, Na++
, NH, NH44
++
etc.) with Hetc.) with H++
ions and then through anion-exchange units whichions and then through anion-exchange units which
exchange all anions (SO4exchange all anions (SO4----
, Cl, Cl--
, HCO, HCO33
--
, NO, NO33
--
, SiO, SiO33
--
etc.) with OHetc.) with OH--
ions.ions.
• R-HR-H++
+ NaCl = R-Na+ NaCl = R-Na++
+ HCl+ HCl
• R-OHR-OH--
+ NaCl = R-Cl+ NaCl = R-Cl--
+ NaOH+ NaOH

48. Process Flow Diagram of MPL Water Treatment PlantProcess Flow Diagram of MPL Water Treatment Plant
•
ClarifierClarifier
Demi water
Storage TankRaw water Storage
Tank
Pressure
filter
Activated
Carbon filter
Mixed-bed
Cation
Exchanger
Degasified
water Tank
Anion-
exchanger

49. Ion Exchange Resin MechanismIon Exchange Resin Mechanism
Cation Resin Sodium chloride
R-OH-
+ Cl-
= R- Cl-
+ OH-
(Hydroxyl ion)
R-HR-H++
+ Na+ Na++
= R-Na= R-Na++
+ H+ H++
(Hydrogen ion)(Hydrogen ion)
Anion Resin
H+
+ OH-
= H2O ( Water)
Regeneration- R-Na+
+ H +
= R- H+
+ Na+
R-Cl-
+ OH-
= R- OH-
+ Cl-

50. Normal Regeneration procedureNormal Regeneration procedure
of cation & anion:of cation & anion:
Step Duration,
min.
1. C/E Service, A/E Surface wash 15
2. C/E Surface wash, A/E Settling 15
3. C/E Settling, A/E Settling 5
4. C/E Compression, A/E Compression 6
5. C/E 1st
H2SO4 injection (1.85%), A/E NaOH injection (3.0 –
3.2%).
-
C/E 2nd H2SO4 injection (3.7%), A/E NaOH injection (3.0 -
3.2%).
-
8. C/E & A/E Displacement 50
9. C/E Rinse, A/E Stand-by 50
10. C/E Service, A/E Rinse. 50

51. Special Regeneration procedureSpecial Regeneration procedure
of cation & anionof cation & anion
Step Duration,
min.
Flow,
m3
/hr.
1. C/E Service, A/E Backwash 20 15, 7.00
2. C/E Backwash, A/E Settling 30 25.00
3. C/E Settling, A/E Settling 5 -
4. C/E Compression, A/E Compression 6 -
5. C/E 1st
H2SO4 injection (1.85%), A/E NaOH injection (3.0%). - 12.00
C/E 1st
H2SO4 injection (3.7%), A/E NaOH injection (3.0%). - 7.00
6. H2SO4 Refill, NaOH Refill. 2 -
7. C/E 3rd H2SO4 injection (4.0%), - -
A/E 2nd
NaOH injection (3.0-3.2%). - -
C/E Stand-by, A/E NaOH injection (3.0 – 3.2%). - -
8. C/E & A/E Displacement 60 -
9. C/E Rinse, A/E Stand-by 50 -
10. C/E Service, A/E Rinse. 50 -

52. Regeneration procedure of M.B.PRegeneration procedure of M.B.P
Step Duration, min.
1. Backwash 20
2. Settling 5
3. NaOH injection (5 – 6 %) at 500
C. -
4. Displacement 50
5. H2SO4 injection (5 – 6 %) at 500
C. -
6. Displacement 50
7. First Rinse 40
8. Drain 20
9. Air Mixing 10
10. Fill-up 5
11. Second Rinse 40
12. Stand -by -
13.Blow down 3

53. Types of RegenerationTypes of Regeneration
• Co-current flow regenerationCo-current flow regeneration
• Counter current flow regenerationCounter current flow regeneration
• Counter current UPCORE (Packed Bed Up-Flow) regenerationCounter current UPCORE (Packed Bed Up-Flow) regeneration

54. The Meaning of pH in Water TreatmentThe Meaning of pH in Water Treatment
1212 OHOH--
AlkalinityAlkalinity 500 ppm as CaCO3500 ppm as CaCO3
1111 OHOH--
AlkalinityAlkalinity 50 ppm as CaCO350 ppm as CaCO3
1010 OHOH--
AlkalinityAlkalinity 5 ppm as CaCO35 ppm as CaCO3
99
88
77 Neutral at 25Neutral at 25 oo
CC
66
55
44 Free Mineral AcidFree Mineral Acid 4 ppm as CaCO34 ppm as CaCO3
33 Free Mineral AcidFree Mineral Acid 40 ppm as CaCO340 ppm as CaCO3
22 Free Mineral AcidFree Mineral Acid 400 ppm as CaCO3400 ppm as CaCO3
11 Free Mineral AcidFree Mineral Acid
Strong Base
Anion Exch
Effluent
Strong
Acid
Cation
Exch
Effluent

55. Waste water treatment PlantWaste water treatment Plant
(ETP)(ETP)
Waste water treatment PlantWaste water treatment Plant
(ETP)(ETP)
Waste water should be disposed after proper treatment to safe theWaste water should be disposed after proper treatment to safe the
environment.environment.
ETP includes aeration ,clarification and sludge treatment, oilETP includes aeration ,clarification and sludge treatment, oil
separation,separation, pH neutralization, chlorination & dechlorination etc.
by following the national environmental regulations.
A recent trend in effluent water treatment is Zero LiquidA recent trend in effluent water treatment is Zero Liquid
Discharge (ZLD) .This means no water is discharged from theDischarge (ZLD) .This means no water is discharged from the
plant. Water is reclaimed.plant. Water is reclaimed.

56. ThanksThanks