Water Chemistry

Water CycleWater Cycle

WaterWater

• Physical Properties of waterPhysical Properties of watera)a) Physical StatePhysical State

b)b) Surface TensionSurface Tension

c)c) Specific GravitySpecific Gravity

d)d) ViscosityViscosity

e)e) ConductivityConductivity

Physical StatePhysical State

• SolidSolidWhen water is solid State, as ice. The molecules are When water is solid State, as ice. The molecules are bonded to each other in a solid crystalline structure. The bonded to each other in a solid crystalline structure. The structure is six sided, with each molecule of water is structure is six sided, with each molecule of water is connected to four others with hydrogen bonds. Because connected to four others with hydrogen bonds. Because of the way the crystal is arranged, there is actually more of the way the crystal is arranged, there is actually more empty space between the molecules than is in liquid empty space between the molecules than is in liquid water, so ice is less dense. That is why ice floats. The water, so ice is less dense. That is why ice floats. The latent heat of fusion (Ice to water) is 80 calories per gram latent heat of fusion (Ice to water) is 80 calories per gram of ice. of ice.


• LiquidLiquidWhen the water is in Liquid state, some of molecules bond When the water is in Liquid state, some of molecules bond to each other with hydrogen bonds. The bonds break and to each other with hydrogen bonds. The bonds break and re-form continually.re-form continually.

Liquid evaporates and changes to gas (vapors). Energy is Liquid evaporates and changes to gas (vapors). Energy is required to change from solid to gas. If the water is at a required to change from solid to gas. If the water is at a temperature of 100 C (that is boiling Point) it take an temperature of 100 C (that is boiling Point) it take an additional 540 calories of heat to convert one gram of water additional 540 calories of heat to convert one gram of water to gas state. to gas state.

Physical statePhysical state

• GasGasWhen the water is in vapor state, as a gas, the water When the water is in vapor state, as a gas, the water molecules are not bonded each other. They float around a molecules are not bonded each other. They float around a single molecule.single molecule.

To get the molecule of water vapor to become liquid again, To get the molecule of water vapor to become liquid again, we have to take the energy away, that is, we have to cool it we have to take the energy away, that is, we have to cool it down so that it condenses( condensation is the change down so that it condenses( condensation is the change from vapor state to the liquid state). When water from vapor state to the liquid state). When water condenses, it releases latent latent heat. condenses, it releases latent latent heat.


• Surface tensionSurface tensionSurface tension is an effect within the surface layer of a Surface tension is an effect within the surface layer of a liquid that causes the layer to behave as an elastic sheet. liquid that causes the layer to behave as an elastic sheet. This effect allows insect (such as water strider) to walk on This effect allows insect (such as water strider) to walk on water.water.


Specific Gravity

Specific gravity is relative density of water with respect to density of water at 4 C

Water density changes with temperature and slightly with pressure.

Water Specific gravity at 4C is 1.0. Its value decreases as the water temperature decreases or increases.

Physical state (Viscosity)Physical state (Viscosity)

TemperatuTemperature re

Dynamic Dynamic ViscosityViscosity

1010 1.3071.307

2020 1.0021.002

3030 0.7980.798

4040 0.6630.663

5050 0.5470.547

6060 0.4670.467

7070 0.4040.404

8080 0.3550.355

9090 0.3150.315

100100 0.2820.282

In any flow, layers moves at different velocities and the fluid viscosity arises from the shear stress between the layers that ultimately opposes any applied force.

There are two type of viscosity

Absolute or dynamic and kinematic. Fluid viscosity varies with temperature. The viscosity is expressed poise, centipoise and millipoise

Physical properties (TDS)Physical properties (TDS)

TDS Total dissolved SolidsTDS Total dissolved Solids

Total dissolved solids is measured by evaporating known quantity of and Total dissolved solids is measured by evaporating known quantity of and

then dried at 180 then dried at 180 ooC . At this temperature Bicarbonate dissociate and C . At this temperature Bicarbonate dissociate and

liberate COliberate CO22 and water. and water.

Ca(COCa(CO33))22 ---------------- CO ---------------- CO22 + H + H22O O

To correct the results amount of liberated constitute has to be added in the results. To correct the results amount of liberated constitute has to be added in the results.

Evaporation method cannot be conducted at site, since it required sophisticated Evaporation method cannot be conducted at site, since it required sophisticated

equipments. equipments.

04/19/2304/19/23 1010

Physical propertiesPhysical properties

• ConductivityConductivity Conductivity is the ability to conduct electric current in a Conductivity is the ability to conduct electric current in a

solution. Two plates (cells) are placed in the sample, a potential solution. Two plates (cells) are placed in the sample, a potential is applied across the plate and current is measured. Conductivity is applied across the plate and current is measured. Conductivity is measured from the voltage and current value according to is measured from the voltage and current value according to ohm‘s lawohm‘s law

G=1/R = Amp/VoltG=1/R = Amp/Volt

Since the charge on ions facilitates the conductance of electric Since the charge on ions facilitates the conductance of electric current, the conductivity is proportional to its ion concentration. current, the conductivity is proportional to its ion concentration. The area of plates and the distance in plates determines the The area of plates and the distance in plates determines the value of cell constant. Cell constant 0.1 measure conductivity value of cell constant. Cell constant 0.1 measure conductivity 0.5 – 400 0.5 – 400 µµS, cell constant 1.0 in range 10 – 2000 S, cell constant 1.0 in range 10 – 2000 µµS while cell S while cell constant 10 in range 1000 – 200,000 constant 10 in range 1000 – 200,000 µµS.S.

Physical PropertiesPhysical Properties

Total dissolved Solids &

Conductivity

Relationship between

conductivity and TDS varies

and depends upon

• Ionic concentration

• Types of ions

• Water temperature


Ionic ConcentrationIonic ConcentrationSince conductivity of solution Since conductivity of solution depends upon the ionic mobility, depends upon the ionic mobility, as the concentration of Sodium as the concentration of Sodium chloride increases the ionic chloride increases the ionic mobility decreases. The ratio mobility decreases. The ratio conductivity/TDS (Factor) conductivity/TDS (Factor) increases. increases.

ConductivityConductivity

At 25 CAt 25 C

8484 uS uS

447447 uS uS

1413 uS1413 uS

1500 uS1500 uS

8974 uS8974 uS

1288012880 uS uS

15000 uS15000 uS

80 mS80 mS

TDS NaClTDS NaCl

38 38

215215.5

702.1

737.1737.1

44874487

72307230

85328532

4838448384

FactorFactor

00. 4755. 4755

0.4822

0.4969

0.4914

0.5000

0.5513

0.5688

0.6048

Physical Properties Physical Properties

Types of ionsTypes of ionsSince Conductivity depends Since Conductivity depends upon the ionic mobility as well upon the ionic mobility as well size and the charge on the size and the charge on the ions, therefore at same ions, therefore at same concentration of salts concentration of salts different salts have different different salts have different conductivities conductivities

ComponenComponentt

HClHCl

HNOHNO33

HH22SOSO44

HH33POPO44

NaOHNaOH

KOHKOH

NHNH4 4 OHOH

NaClNaCl

NaNa22SOSO44

NaNa22COCO33

NaHCONaHCO33

KClKCl

Infinite Infinite dilutiondilution

426426

421421

430430

419419

248248

271271

271271

126126

130130

124124

9696

150150

ConcentratiConcentration 100 on 100 meq/litmeq/lit

392392

386386

317317

104104

221221

246246

3.93.9

107107

9090

86.386.3

7676

129129


Temperature effect on conductivity

Chemical propertiesChemical properties

pHpH In water (HIn water (H22O) one of the hydrogen atom jumps over one of the O) one of the hydrogen atom jumps over one of the

pairs of unshared electrons to another water molecule (leaving its pairs of unshared electrons to another water molecule (leaving its electron behind). Thus ions of H3Oelectron behind). Thus ions of H3O++ (hydronium ion) and OH (hydronium ion) and OH-- ion ion (hydroxide ions) are formed.(hydroxide ions) are formed.

2 H2 H22O HO H33OO++ + OH + OH--

In one liter of water there will be 0.0000001 M each of HIn one liter of water there will be 0.0000001 M each of H33OO++ (often (often written as H+) and of OH present, For easy and in simplest form. written as H+) and of OH present, For easy and in simplest form. The ionic concentration can be written as 1x10 -7. If we write it in The ionic concentration can be written as 1x10 -7. If we write it in logarithm for it would be –log [Hlogarithm for it would be –log [H++] = 7. –log [pH] = 7. –log [pH++] is known as pH. ] is known as pH.

WATER SOURCESWATER SOURCES

1.WELL WATER1.WELL WATER

a. SHALLOW WELLSa. SHALLOW WELLS

b. DEEP WELLSb. DEEP WELLS

2.SURFACE WATER2.SURFACE WATER

a. RIVERa. RIVER

b. LAKEb. LAKE

3.SEA WATER3.SEA WATER

a. OPEN SEA INTAKEa. OPEN SEA INTAKE

b. BEACH WELLSb. BEACH WELLS

WATER CHEMISTRYWATER CHEMISTRY

Water Composition – Suspended ImpuritiesWater Composition – Suspended Impurities

- Suspended Solids- Suspended Solids

- Organics Compounds- Organics Compounds

- Iron- Iron

- Slit- Slit

- Bacteria- Bacteria


Water Composition – Dissolved ImpuritiesWater Composition – Dissolved Impurities

CationsCations- Calcium (Ca)- Calcium (Ca)

- Magnesium (Mg)- Magnesium (Mg) - Sodium (Na)- Sodium (Na) - Potassium (K)- Potassium (K)

- Barium (Ba)- Barium (Ba)- Strontium (Sr)- Strontium (Sr)


Anions Anions - Carbonate (CO3)- Carbonate (CO3)- Bicarbonate (HCO3)- Bicarbonate (HCO3)- Sulphate (SO4)- Sulphate (SO4)- Nitrate (NO3)- Nitrate (NO3)- Nitrite (NO2)- Nitrite (NO2)- Chloride (Cl)- Chloride (Cl)- Floride (F)- Floride (F)- Silica (Si)- Silica (Si)

WATER CLASSIFICATIONS BASED WATER CLASSIFICATIONS BASED ON TOTAL DISSOLVED SOLIDS ON TOTAL DISSOLVED SOLIDS

(TDS)(TDS)

FRESH FRESH < 1000 ppm < 1000 ppm

BRACKISH BRACKISH 1000-5000 ppm1000-5000 ppm

HIGLLY BRACKISH 5000-15000 ppmHIGLLY BRACKISH 5000-15000 ppm

SALINE SALINE 15000-30000 ppm15000-30000 ppm

SEA WATER SEA WATER 30000-40000 ppm30000-40000 ppm

BRINE BRINE 40000-300000 ppm40000-300000 ppm

WATER TREATMENT PROCESSESWATER TREATMENT PROCESSES

• Clarification / Sedimentation

• Chlorination

• Filtration

• Lime Soda Softening

• Softening Through Ion Exchange

• Demineralization

• De-Alkalizers

• Reverse Osmosis

CLARIFICATION / SEDIMENTATION

For the removal high suspended solids, above 50 mg/l. Specially suitable for canal / river (surface water treatment).

FILTERATION

For the removal of suspended solids (TDS <50 ppm)

Different Types of filling media are used,

based on particular application.

FILTERATION MEDIAFILTERATION MEDIA

• Silica Sand

• Gravel

• Anthracite

• Activated Carbon

• Anthracite

• Birm

• Manganese Green

• Hydrofilt

ACIDIFICATIONACIDIFICATION

Lowers p H Lowers p H

Decreases Scaling IndicesDecreases Scaling Indices

Increases calcium sulfate scalingIncreases calcium sulfate scaling

No impact on TDS of feed waterNo impact on TDS of feed water

Increases blow down rateIncreases blow down rate

Predicted Water Analysis After Acid Injection

Locations

1 Shahkot Kurrianwala Area 4 After Four Cycles Concentration

2 After Acid Addition

3 Cooling Tower Basin

Elements Units 1 2 3 4 5

Calcium Ca++ CaCO3 190 190 190 751

Magnesium Mg++ CaCO3 279 279 279 1103

Sodium Na+ CaCO3 1085 1085 1085 4241

Total Cation CaCO3 1554 1554 1554 6095

Bicarbonates HCO3- CaCO3 711 432 432 1672

Chloride Cl- CaCO3 422 417 417 2792

Sulfate SO4-- CaCO3 421 705 705 1631

Total Anion CaCO3 1554 1554 1554 6095

Total Hardness CaCO3 469 469 469 5

Carbonate Hardness CaCO3 469 432 432 5

Non-Carbonate Hardness CaCO3 0 37 37

Scaling Indices LSI -0.3 1.1 >2.6

m Alkalinity CaCO3 711 432 432 711

pH pH scale 7.8 6.5 7.95 8.2

Total Dissolved Solids mg/lit. 2235 2235 2235 8390

LIME SODA SOFTENING

Removes hardness associated with alkalinity

Precipitation of calcium and magnesium carbonate produces huge volume of sludge

Sludge disposal causes problem

Decreases the total dissolved solids

Blow down rate decreases

SOFTENING THROUGH ION EXCHANGE

• Removal of Calcium & Magnesium by

Sodium ions

• Soft Water does not reduce total

dissolved Solids.

• To some extent Iron removal

SOFTENING THROUGH ION SOFTENING THROUGH ION EXCHANGEEXCHANGE

The softening of water by ion exchange The softening of water by ion exchange involves the replacement of calcium and involves the replacement of calcium and magnesium ions in water by an equivalent magnesium ions in water by an equivalent number of sodium ions. This eliminates the number of sodium ions. This eliminates the undesirable characteristics of hardness in undesirable characteristics of hardness in water, as sodium salts do not form scale. The water, as sodium salts do not form scale. The chemical reaction is as under:chemical reaction is as under:


Basic Ion Exchange Mechanism is as follows:Basic Ion Exchange Mechanism is as follows:

2RcSO3Na + Ca(HCO3)2 = (RcSO3)2Ca + 2NaHCO32RcSO3Na + Ca(HCO3)2 = (RcSO3)2Ca + 2NaHCO3

(Sodium (Calcium (Calcium (Sodium(Sodium (Calcium (Calcium (Sodium

Exchange Bicarbonate Exchange BicarbonateExchange Bicarbonate Exchange Bicarbonate

Regenerated in Raw Water) Exhausted In SoftRegenerated in Raw Water) Exhausted In Soft

Resin) Resin) Water)Resin) Resin) Water)


The sodium ion exchanger contains only a finite The sodium ion exchanger contains only a finite number of exchangeable sodium ions. This number number of exchangeable sodium ions. This number is known as the capacity of the resin. When this is known as the capacity of the resin. When this capacity has been exhausted, i.e., sodium ions have capacity has been exhausted, i.e., sodium ions have been replaced by calcium or magnesium, been replaced by calcium or magnesium, regeneration of the resin back to sodium form regeneration of the resin back to sodium form becomes necessary. Resin bed is regenerated with a becomes necessary. Resin bed is regenerated with a downward flow of brine. Later, resin bed is rinsed downward flow of brine. Later, resin bed is rinsed free off brine. The chemical reaction is as under:free off brine. The chemical reaction is as under:


Regeneration of Resin through brine solution is as follows:Regeneration of Resin through brine solution is as follows:

(RcSO3)2Mg,Ca + 2NaCl = 2RcSo3Na + MgCl2 , CaCl2(RcSO3)2Mg,Ca + 2NaCl = 2RcSo3Na + MgCl2 , CaCl2

(Exhausted (Brine) (Regenerated (Effluent)(Exhausted (Brine) (Regenerated (Effluent)

Resin) Resin)Resin) Resin)

DE-ALKALIZERS

Removes cations and associated alkalinity from the water.

Degasifier is used for removal of bicarbonate alkalinity

Effective for high alkalinity waters

TDS reduces equivalent to alkalinity.

DE-ALKALIZER

Basic Ion Exchange Mechanism is as Basic Ion Exchange Mechanism is as follows:follows:

2RcSO3H + Ca(HCO3)2 = (RcSO3)2Ca + 2H2CO3, HCl, H2SO42RcSO3H + Ca(HCO3)2 = (RcSO3)2Ca + 2H2CO3, HCl, H2SO4

(Sodium (Ca, Mg, Na (Ca, Mg, Na (Acid) (Sodium (Ca, Mg, Na (Ca, Mg, Na (Acid)

Exchange Bicarbonates, Exchange Exchange Bicarbonates, Exchange

Regenerated Chlorides & Exhausted Regenerated Chlorides & Exhausted

Resin) Sulphates) Resin) Resin) Sulphates) Resin)

DEMINERALIZATION PLANT

• Removal of complete or selective ions to

minimize total dissolved solids.

• Feed Water TDS is limiting factor

TDS < 200 ppm – Demin. Plant

TDS > 200 ppm – R.O. Plant

DEMINERALIZATION PLANTDEMINERALIZATION PLANT

REVERSE OSMOSIS

Reverse Osmosis

Reverse Osmosis can be defined as the separation of one component of a solution from another component by mean of pressure exerted on a semi-permeable membrane.

Reverse osmosis requires external pressure to reverse natural osmotic flow. As pressure is applied to the saline solution, water flows through the semi-permeable membrane (see figure 3).

REVERSE OSMOSISREVERSE OSMOSIS


FeedSolution which enters the system and is pressurized.

PermeateSolution which passes through the membrane and is collected for use.

RejectThe percentage of dissolved material that does not pass through membrane.


PassageThe percentage of dissolved material that does

Pass Through the membrane

RecoveryThe ratio of permeate rate to feed rate

Permeate Rate

Recovery (%) = ------------------- × 100

Feed Rate

CHEMICAL INJECTION SYSTEM

GENERALLY AN ANTISCALANT MUST BE ADDED TO THE FEEDWATER FOR PROPER REVRSE OSMOSIS SYSTEM PERFORMANCE

ADDITION PRETREATMENT CHEMICAL INJECTION

SYSTEMS FOR CHLORINATION, DECHLORINATION

AND COAGULANT INJECTION

POST-TREATMENT INCLUDES CHLORINATION AND pH ADJUSTMENT

PRE & POST TREATMENT

REVERSING PROBLEM IN R.O.

ACTIVATED CARBON FILTERS ARE GENERALLY USED

IN SMALLER REVERSE OSMOSIS UNITS TO REMOVE

CHLORINE.

FOR LARGER UNITS, DECHLORINATION IS

ACCOMPLISHED EITHER BY AN UPSTREAM

GRANULAR AC BED OR BY INJECTION OF A SULFITE

GENERATING SO3 COMPOUND

CHEMICAL ATTACK

CHLORINE IS THE MOST COMMON AGENT TO CHEMICALLY

ATTACK AND DESTROY FREQUENTLY USED POLYAMIDE THIN-

FILM MEMBRANES

REVERSING PROBLEM IN R.O.

BACTERIA

ALUMINIUM

IRON

SILICA

FOULING

FOULING RESULTS WHEN FEED WATER SUSPENDED

PARTICLES ARE DEPOSITED WITHIN AN REVERSE OSMOSIS

UNIT. THE MOST COMMON FOULING PARTICLES ARE

REVERSING PROBLEMS IN R.O.

SCALING

FOULING

CHEMICAL

THE USEFUL LIFE OF REVERSE OSMOSIS MEMBRANE ELEMENT IS REDUCED BY

CALCIUM CARBONATE (LIMESTONE)

CALCIUM SULFATE (GYPSUM)

SCALING

TWO MOST COMMON SCALANTS ARE

SCALANTS ARE EFFECTIVELY REMOVED BY CHEMICAL CLEANING HYDROCHLORIC ACID

CITRIC ACID

SIX STEPS TO BETTER R.O.OPERATION

TOTAL DISSOLVED SOLIDS (TDS)

FEED PRESSURE

FEED TEMPERATURE

FEED WATER pH

WATER DISINFECTION

IMPURITIES

OBSERVE THESE PARAMETERS TO ENSURE A SYSTEM’S PEAK PERFORMANCE.

WATER QUALITY REQUIREMENTS WATER QUALITY REQUIREMENTS FOR PROCESS INDUSTRIESFOR PROCESS INDUSTRIES

1.1. Water for Cooling Towers & Heat ExchangersWater for Cooling Towers & Heat Exchangers

2.2. Water for Processing UnitsWater for Processing Units

3.3. Water for BoilersWater for Boilers

WATER FOR COOLING TOWERS & WATER FOR COOLING TOWERS & HEAT EXCHANGERSHEAT EXCHANGERS

Fundamentals:Fundamentals:1.1. Air Quality affects Water QualityAir Quality affects Water Quality

2.2. FilterationFilteration

3.3. Contamination & TurbidityContamination & Turbidity

4.4. Blow DownBlow Down

5.5. Chemical TreatmentChemical Treatment

(Scale Preventation, Corrosion Control, Control of (Scale Preventation, Corrosion Control, Control of Biological Growth, Foaming, Control of Suspended Biological Growth, Foaming, Control of Suspended Impurities)Impurities)

PARAMETERS TO CONTROL FOR PARAMETERS TO CONTROL FOR COOLING TOWERSCOOLING TOWERS

• Total HardnessTotal Hardness

• Total AlkalinityTotal Alkalinity

• IronIron

• Total Bacteria Count / Sulfate Reducing BacteriaTotal Bacteria Count / Sulfate Reducing Bacteria

• p Hp H

• SilicaSilica

• Total Dissolved SolidsTotal Dissolved Solids

• Algae / FungiAlgae / Fungi

WATER FOR PROCESSING UNITSWATER FOR PROCESSING UNITS

High level of total hardness, alkalinity, chlorides and High level of total hardness, alkalinity, chlorides and iron in water increases the chemicals consumption iron in water increases the chemicals consumption and affects the final quality of processed fabrics.and affects the final quality of processed fabrics.

Water is also used in manufacturing pharmaceutical Water is also used in manufacturing pharmaceutical products, preparation of injectable impulse and in products, preparation of injectable impulse and in food industries. food industries.

The quality of water may vary from industry to The quality of water may vary from industry to industry but treatment is required for every industry but treatment is required for every application.application.

OVER VIEW OF APPLICATIONSOVER VIEW OF APPLICATIONS

Impurities to RemoveImpurities to Remove Treatment ProcessTreatment Process

To remove hardnessTo remove hardness Softening Unit based on Softening Unit based on Ion ExchangeIon Exchange

To reduce TDSTo reduce TDS Reverse Osmosis / De-Reverse Osmosis / De-IonizerIonizer

To reduce AlkalinityTo reduce Alkalinity De-Alkalizer / AcidificationDe-Alkalizer / Acidification

To remove temporary To remove temporary hardnesshardness

Lime Treatment Lime Treatment (Softening)(Softening)

WATER QAUALITY AT DIFFERENT LOCATION

Locations

1 Shahkot Khurianwala Area 4. Mirpur Mathelo

2 Raiwind Manga Mandi Area 5. Rawalpindi Area

3 Nishatabad Area Faisalabad


Calcium Ca++ CaCO3 190 45 138 210 150

Magnesium Mg++ CaCO3 279 13 346 180 150

Sodium Na+ CaCO3 1085 706 3199 859 370

Total Cation CaCO3 1554 764 3683 1249 670

Bicarbonates HCO3- CaCO3 711 250 775 400 196

Chloride Cl- CaCO3 421 493 1754 465 282

Sulfate SO4-- CaCO3 422 21 1154 384 192

Total Anion CaCO3 1554 764 3683 1249 670

Total Hardness CaCO3 469 58 482 390 300

Carbonate Hardness CaCO3 469 58 482 390 104

Non Carbonate Hardness CaCO3 0 0 0 10 196

m Alkalinity CaCO3 711 250 775 400 196

Sodium Alkalinity CaCO3 242 192 293 10 0

pH pH scale 7.8 7.85 7.9 7.5 7.9

Total Dissolved Solids mg/lit. 2235 1016 5000 1820 872

INTERPRETATION OF WATER INTERPRETATION OF WATER ANALYSISANALYSIS

PREDICATED TREATED WATER ANALYSIS (DE-ALKALIZER & WATER SOFTENING)

Locations

1 Shahkot Khurianwala Area 4. After Softner

2 After De-Alkalizer 5. 50% blend of (3 & 4)

3 After De Gasifier


Calcium Ca++ CaCO3 190 0 0 2 1

Magnesium Mg++ CaCO3 279 0 0 3 2

Sodium Na+ CaCO3 1085 0 0 1549 774

Hydrogen H+ CaCO3 1554 863 87

Total Cation CaCO3 1554 1554 863 1554 863

Bicarbonates HCO3- CaCO3 711 711 <20 711 20

Chloride Cl- CaCO3 421 421 421 421 421

Sulfate SO4-- CaCO3 422 422 422 422 422

Total Anion CaCO3 1554 1554 863 1554 863

Total Hardness CaCO3 469 5 3

Carbonate Hardness CaCO3 469 5 3

m Alkalinity CaCO3 711 <20 711 <20

Sodium Alkalinity CaCO3 242

pH pH scale 7.8 <2 7.8 <5.0

Total Dissolved Solids mg/lit. 2235 <1000 <1200

PREDICTED TREATED WATER ANALYSIS (AFTER LIME SODA SOFTENING)

Locations

1 Rawalpindi Area

2 After Lime Soda Softening



Calcium Ca++ CaCO3 150 13 13

Magnesium Mg++ CaCO3 150 12 12

Sodium Na+ CaCO3 370 474 474

Total Cation CaCO3 670 499 499

Bicarbonates HCO3- CaCO3 196 25 10

Chloride Cl- CaCO3 282 282 282

Sulfate SO4-- CaCO3 192 192 207

Total Anion CaCO3 670 499 499

Total Hardness CaCO3 300 25 25

Carbonate Hardness CaCO3 104 25 10

Non-Carbonate Hardness CaCO3 196 0 15

m Alkalinity CaCO3 196

pH pH scale 7.9 10 <8.0

Total Dissolved Solids mg/lit. 872 640 640

Predicted RO Water Analysis (85 % Conversion)

Locations

1 Rawalpindi Area 4 Concentrate


3 Product Water


Calcium Ca++ CaCO3 150 150 0.71 973

Magnesium Mg++ CaCO3 150 150 0.71 973

Sodium Na+ CaCO3 370 370 8.7 2060

Total Cation CaCO3 670 670 10.12 4006

Bicarbonates HCO3- CaCO3 197 177 3.87 1070

Chloride Cl- CaCO3 239 239 5.6 1529

Sulfate SO4-- CaCO3 234 254 0.53 1407

Total Anion CaCO3 670 670 10.12 4006

Total Hardness CaCO3 300 300 1.5 1946

Carbonate Hardness CaCO3 197 134 2.37 1058

Non-Carbonate Hardness CaCO3 103 166 1.5 888

m Alkalinity CaCO3

pH pH scale 7.9 7 5.37 7.81

Total Dissolved Solids mg/lit. 860 852 14 5475

GLOSSARYGLOSSARY

Activated CarbonActivated Carbon Granulated activated carbon used to remove tastes, odor, chlorine, Granulated activated carbon used to remove tastes, odor, chlorine,

chloramines and some organics from waterchloramines and some organics from water

AerationAeration The process of adding air to the water supply for the purpose of The process of adding air to the water supply for the purpose of

oxidizing or mixingoxidizing or mixing

Alkalinity Alkalinity Capacity for neutralizing acid, usually due to presence of bicarbonate Capacity for neutralizing acid, usually due to presence of bicarbonate

or carbonate ions. Hydroxide, borate, silicate, and phosphate ions may or carbonate ions. Hydroxide, borate, silicate, and phosphate ions may contribute to alkalinity in treated waters contribute to alkalinity in treated waters

GLOSSARYGLOSSARY

Anion Anion Negatively charged ion in a solutionNegatively charged ion in a solution

Aquifer Aquifer Natural, underground porous formation where mineral-Natural, underground porous formation where mineral-

bearing water flows or is stored. Source of well waterbearing water flows or is stored. Source of well water

ASTM ASTM Stands for 'American Society for Testing and Materials' Stands for 'American Society for Testing and Materials'

BackwashBackwash Reversal of water or solution's flow through a filtration Reversal of water or solution's flow through a filtration system. Backwash process is commonly used in sand and system. Backwash process is commonly used in sand and multi-media filtersmulti-media filters

GLOSSARYGLOSSARYBacteria Bacteria Microscopic single-celled organisms reproducing by Microscopic single-celled organisms reproducing by

fission or by spores. Typically round, rod-like spiral shaped fission or by spores. Typically round, rod-like spiral shaped bodies, often aggregated into colonies or mobile by means bodies, often aggregated into colonies or mobile by means of flagella. Commonly found in soil, water, organic matter, of flagella. Commonly found in soil, water, organic matter, and in the bodies of plants and animals. Often symbiotic in and in the bodies of plants and animals. Often symbiotic in man, but sometimes pathogenic man, but sometimes pathogenic

Blowdown Blowdown In reference to boiler & cooling tower technology, the In reference to boiler & cooling tower technology, the

purge from the system of a small portion of water purge from the system of a small portion of water concentrated with contaminants in order to maintain the concentrated with contaminants in order to maintain the level of dissolved and suspended solids in the system level of dissolved and suspended solids in the system below a certain maximum level below a certain maximum level

BODBOD Biochemical Oxygen Demand – a measure of the amount Biochemical Oxygen Demand – a measure of the amount

of oxygen required for the biochemical degradation of of oxygen required for the biochemical degradation of organic material in a water sample organic material in a water sample

GLOSSARYGLOSSARY

Bottled waterBottled water

Water (usually treated or purified) sold in Water (usually treated or purified) sold in containers for drinking and domestic usecontainers for drinking and domestic use

Carbonate hardnessCarbonate hardness

The hardness in water caused by carbonates and The hardness in water caused by carbonates and bicarbonates of calcium and magnesiumbicarbonates of calcium and magnesium

Cartridge filter Cartridge filter

A filter device, usually disposable. For a detailed A filter device, usually disposable. For a detailed description see end of this bookletdescription see end of this booklet

GLOSSARYGLOSSARYCationCation A positively charged ion in a solutionA positively charged ion in a solution

Chlorine Chlorine A chemical used as bleaching, oxidizing or disinfecting agent in A chemical used as bleaching, oxidizing or disinfecting agent in

water purificationwater purification

Clarification Clarification Filtration of liquids containing small quantities of solidsFiltration of liquids containing small quantities of solids

Coagulant Coagulant Chemical added to water to cause formation of flocs that Chemical added to water to cause formation of flocs that

adsorb, entrap or otherwise bring together suspended adsorb, entrap or otherwise bring together suspended matter defined as colloidal. Used to remove turbidity, matter defined as colloidal. Used to remove turbidity, bacteria, color and other finely divided matter from waterbacteria, color and other finely divided matter from water

COD COD Chemical Oxygen Demand – a measure of the oxygen Chemical Oxygen Demand – a measure of the oxygen

required to oxidize chemicals contained in a sample required to oxidize chemicals contained in a sample

GLOSSARYGLOSSARYColloid Colloid A substance of fine particle size, typically in the range of 0.1 to 0.001 A substance of fine particle size, typically in the range of 0.1 to 0.001

microns, suspended in liquid or air. Such fine particles cannot microns, suspended in liquid or air. Such fine particles cannot normally be filtered out but are removed by reverse osmosis, normally be filtered out but are removed by reverse osmosis, distillation, or ultrafiltration processdistillation, or ultrafiltration process

Colloids Colloids Suspension of submicron particles in a continuous fluid medium that Suspension of submicron particles in a continuous fluid medium that

will not settle out of the mediumwill not settle out of the mediumConcentration Concentration The amount of material contained in a unit volume of fluid. The term is The amount of material contained in a unit volume of fluid. The term is

also used for the process of increasing the dissolved material per unit also used for the process of increasing the dissolved material per unit volumevolume

Conductivity Conductivity The ability of water to transmit electricity, the property being the The ability of water to transmit electricity, the property being the

inverse of resisistivity inverse of resisistivity Cross flow membrane filtrationCross flow membrane filtration A separation of components of a fluid by semi-permeable membranes A separation of components of a fluid by semi-permeable membranes

by application of pressure and parallel flow to the membrane surface; by application of pressure and parallel flow to the membrane surface; processes include reverse osmosis, ultrafiltration, nanofiltration and processes include reverse osmosis, ultrafiltration, nanofiltration and microfiltration microfiltration

GLOSSARYGLOSSARYDeionization Deionization Process utilizing ion exchange resins, which remove ionized salts Process utilizing ion exchange resins, which remove ionized salts

from water to obtain soft water. The process typically removes salts from water to obtain soft water. The process typically removes salts only and not any organics, virus or bacteriaonly and not any organics, virus or bacteria

Delta PDelta P Term donating the pressure drop across a filterTerm donating the pressure drop across a filter

Demineralization Demineralization The process of removing minerals from water, usually by deionization, The process of removing minerals from water, usually by deionization,

reverse osmosis, or distillationreverse osmosis, or distillation

Differential pressure (pressure drop) Differential pressure (pressure drop) The difference in pressure between the upstream and downstream The difference in pressure between the upstream and downstream

sides of a filtersides of a filter Difference in pressure between two points in a system. In filters, this is Difference in pressure between two points in a system. In filters, this is

usually measured between the inlet and outlet of the filter housing, usually measured between the inlet and outlet of the filter housing, and is a determining factor of filter service life. and is a determining factor of filter service life.

GLOSSARYGLOSSARY

Dissolved solidsDissolved solids

These are the residual materials remaining after evaporating the water These are the residual materials remaining after evaporating the water or solution to a dry stateor solution to a dry state

Effective areaEffective area

The total area of the medium exposed to flow in a filter elementThe total area of the medium exposed to flow in a filter element

Element Element

Any structural part of the filter on which the membrane or media is Any structural part of the filter on which the membrane or media is supportedsupported

GLOSSARYGLOSSARY

Feed waterFeed water

Incoming water supply prior to any treatmentIncoming water supply prior to any treatment

Filtration rateFiltration rate

The volume of liquid that passes through a given filter in a The volume of liquid that passes through a given filter in a specified timespecified time

HardnessHardness

The concentration of calcium and magnesium salts in water. The concentration of calcium and magnesium salts in water. Gives rise to scale formation and reacts with soapGives rise to scale formation and reacts with soap

GLOSSARYGLOSSARYIonIon An atom or molecule, which has lost or gained one or more An atom or molecule, which has lost or gained one or more

electrons, thereby acquiring a net electric chargeelectrons, thereby acquiring a net electric charge

Ion ExchangeIon Exchange A process in which ions are preferentially adsorbed from a A process in which ions are preferentially adsorbed from a

solution for equivalently charged ions attached to solid solution for equivalently charged ions attached to solid resin particlesresin particles

LSILSI Langelier Saturation Index – a calculation that predicts Langelier Saturation Index – a calculation that predicts

calcium carbonate precipitation under a specific condition, calcium carbonate precipitation under a specific condition, temperature, pH, TDS, hardness, and alkalinity temperature, pH, TDS, hardness, and alkalinity

Membrane Membrane A polymer film containing highly controlled distribution of A polymer film containing highly controlled distribution of

pores. They serve as a barrier permitting the passage of pores. They serve as a barrier permitting the passage of materials only up to a certain size or character. materials only up to a certain size or character. Membranes are used as the separation device in reverse Membranes are used as the separation device in reverse osmosis, ultrafiltration, nanofiltration, and microfiltrationosmosis, ultrafiltration, nanofiltration, and microfiltration

GLOSSARYGLOSSARY

Micron Micron Metric unit of measurement equivalent to 10-6 Metric unit of measurement equivalent to 10-6

meters or one millionth of a meter (mictometer). The meters or one millionth of a meter (mictometer). The naked human eye can see particles of 20 microns naked human eye can see particles of 20 microns and above. Particles of size 0.03 to 19 microns can be and above. Particles of size 0.03 to 19 microns can be seen with a microscope and those of 0.001 to 0.2 seen with a microscope and those of 0.001 to 0.2 microns only with an electron microscope microns only with an electron microscope

Mixed-bed Mixed-bed An ion exchange tank consisting of both cation and An ion exchange tank consisting of both cation and

anion resin mixed together. It is used to polish water anion resin mixed together. It is used to polish water already treated by two bed softening tanks or reverse already treated by two bed softening tanks or reverse osmosis. Mixed-bed gives the most complete osmosis. Mixed-bed gives the most complete deionization of water up to 18.3 megaohm/cm deionization of water up to 18.3 megaohm/cm resistivity resistivity

GLOSSARYGLOSSARYNanofiltration (NF) Nanofiltration (NF) Crossflow membrane separation process for removing Crossflow membrane separation process for removing

particles in the 250 to 1000 molecular weight range, particles in the 250 to 1000 molecular weight range, selected salts and most organics. Nanofiltration is often selected salts and most organics. Nanofiltration is often used for water softening and require lower driving used for water softening and require lower driving pressure than ROpressure than RO

NTU NTU Nephelometeric Turbidity Units – a measurement obtained Nephelometeric Turbidity Units – a measurement obtained

by passing a light beam through a low-turbidity water by passing a light beam through a low-turbidity water sample with a nephelometersample with a nephelometer

Osmotic pressureOsmotic pressure It is the measurement of the potential energy difference It is the measurement of the potential energy difference

between solutions on either side of a semi permeable between solutions on either side of a semi permeable membrane membrane

Oxidation Oxidation A process by which electrons are lost to an oxidizing agent A process by which electrons are lost to an oxidizing agent

in order to increase a molecule or ion in positive valence in order to increase a molecule or ion in positive valence

GLOSSARYGLOSSARYPermeability Permeability The property of a filter medium that permits a fluid to pass through under a pressure The property of a filter medium that permits a fluid to pass through under a pressure

differential.differential.

Permeable Permeable A media which allows some material to pass through. A media which allows some material to pass through.

Permeate Permeate That portion of the feed stream, which passes through a membrane, leaving behind a That portion of the feed stream, which passes through a membrane, leaving behind a

more concentrated stream. more concentrated stream.

Permeator Permeator A hollow fibre membrane element consisting of thousands of hollow fibresA hollow fibre membrane element consisting of thousands of hollow fibres. .

pH pH It is the negative logarithm of the hydrogen ion concentration. The range is from 0 to 14, It is the negative logarithm of the hydrogen ion concentration. The range is from 0 to 14,

with 7 as neutral, 0 to less than 7 as acidic, and 7 to 14 as alkaline. with 7 as neutral, 0 to less than 7 as acidic, and 7 to 14 as alkaline.

PorosityPorosity A measure of the open area of a filter medium. Sometimes expressed as a void volume. A measure of the open area of a filter medium. Sometimes expressed as a void volume.

GLOSSARYGLOSSARY

PPBPPB Parts per Billion – approx. equivalent to micrograms per literParts per Billion – approx. equivalent to micrograms per liter

PPM PPM Parts per Million – approx. equivalent to milligrams per literParts per Million – approx. equivalent to milligrams per liter

PPT PPT Parts per Trillion – approx. equivalent to nanograms per literParts per Trillion – approx. equivalent to nanograms per liter

PSI PSI Pounds per square inch pressurePounds per square inch pressure

PSIG PSIG Pounds per square inch gaugePounds per square inch gauge

GLOSSARYGLOSSARYRegenerationRegeneration The displacement from the ion exchange resin of the ions removed The displacement from the ion exchange resin of the ions removed

from the process water. In the water softening process, when most of from the process water. In the water softening process, when most of the sodium ions have been replaced by hardness ions, the resin is the sodium ions have been replaced by hardness ions, the resin is exhausted and must be regenerated. Regeneration is achieved by exhausted and must be regenerated. Regeneration is achieved by passing a concentrated NaCl solution through the resin tanks, passing a concentrated NaCl solution through the resin tanks, replacing the hardness ions with sodium ions. The regeneration replacing the hardness ions with sodium ions. The regeneration process can be repeated indefinitely without damage to the resin process can be repeated indefinitely without damage to the resin provided the incoming water has been properly filtered and by provided the incoming water has been properly filtered and by following the correct procedurefollowing the correct procedure

Rejection Rejection In a membrane system is expressed as a percent of the total presence In a membrane system is expressed as a percent of the total presence

of those contaminants that are larger than the membrane's pore size of those contaminants that are larger than the membrane's pore size and are retained by it or repelled by an electrical chargeand are retained by it or repelled by an electrical charge

Resins (ion exchange)Resins (ion exchange) They consist of polymer beads used in the ion exchange process to They consist of polymer beads used in the ion exchange process to

remove dissolved salts from waterremove dissolved salts from water

GLOSSARYGLOSSARY

Reverse osmosis (RO)Reverse osmosis (RO)

Is the separation of one component of a solution from another Is the separation of one component of a solution from another component by flowing the feed stream under pressure across a component by flowing the feed stream under pressure across a semi permeable membrane to provide a purified stream of semi permeable membrane to provide a purified stream of water. RO removes most organic compounds and up to 99% of water. RO removes most organic compounds and up to 99% of all ions, viruses, bacteria and pyrogens. It is a more energy all ions, viruses, bacteria and pyrogens. It is a more energy efficient process compared to phase change processes efficient process compared to phase change processes (distillation)(distillation)

GLOSSARYGLOSSARYScaling Scaling Is the buildup of precipitated salts on such surfaces as boiler Is the buildup of precipitated salts on such surfaces as boiler

condensate tubes, heat exchangers, pipes, tanks, etc condensate tubes, heat exchangers, pipes, tanks, etc

SDI SDI Silt Density Index – a test used to measure the level of suspended Silt Density Index – a test used to measure the level of suspended

solids in feed water that tend to foul a reverse osmosis system. The solids in feed water that tend to foul a reverse osmosis system. The measurement is the rate at which a 0.45-micron filter will plug with measurement is the rate at which a 0.45-micron filter will plug with particulate material in the source waterparticulate material in the source water

Semi permeable Semi permeable A membrane, which allows a solvent such as water to pass through, A membrane, which allows a solvent such as water to pass through,

while rejecting certain dissolved solids or colloidal substanceswhile rejecting certain dissolved solids or colloidal substances

Specific gravitySpecific gravity Ratio of mass of a solid or liquid to the mass of an equal volume of Ratio of mass of a solid or liquid to the mass of an equal volume of

distilled water, or of a gas to an equal volume of air under prescribed distilled water, or of a gas to an equal volume of air under prescribed temperature and pressuretemperature and pressure

GLOSSARYGLOSSARYSuspended solidsSuspended solids Solid organic and inorganic particles that are held in suspension in Solid organic and inorganic particles that are held in suspension in

water or a solution. water or a solution. Expressed in weight or volumeExpressed in weight or volume

TDS TDS Total Dissolved Solids – a quantity determined by drying the water Total Dissolved Solids – a quantity determined by drying the water

sample and weighing the residue. In the field, TDS is commonly sample and weighing the residue. In the field, TDS is commonly measured by a conductivity meter; however this measurement is measured by a conductivity meter; however this measurement is only an approximationonly an approximation

Turbidity Turbidity A suspension of fine inorganic or organic particles and other A suspension of fine inorganic or organic particles and other

suspended impurities in water that cause cloudiness and will not suspended impurities in water that cause cloudiness and will not readily settle due to small particle size. Generally to remove readily settle due to small particle size. Generally to remove turbidity, the water is treated (by flocculation) and then filteredturbidity, the water is treated (by flocculation) and then filtered

GLOSSARYGLOSSARYUltra-filtration (UF) Ultra-filtration (UF) It is similar to RO & NF, but is defined as cross flow process that It is similar to RO & NF, but is defined as cross flow process that

does not reject ions. UF membranes have a larger pore size and does not reject ions. UF membranes have a larger pore size and therefore require lower operating pressures in 10 to 100 psig range. therefore require lower operating pressures in 10 to 100 psig range. UF removes larger organics, colloids, bacteria, and pyrogens while UF removes larger organics, colloids, bacteria, and pyrogens while allowing most ions and small organics to pass throughallowing most ions and small organics to pass through

Ultraviolet (UV)Ultraviolet (UV) Light with a wavelength of 254 nm used to kill or inactivate Light with a wavelength of 254 nm used to kill or inactivate

pathogens like coliform bacteria and legionella. It disinfects water pathogens like coliform bacteria and legionella. It disinfects water without adding any chemicals or creating any new compounds, nor without adding any chemicals or creating any new compounds, nor does it change the taste or odor of waterdoes it change the taste or odor of water

Water hammerWater hammer Pressure surge produced when the linear flow of non-compressible Pressure surge produced when the linear flow of non-compressible

fluid is rapidly interrupted by devices such as fast-acting valves fluid is rapidly interrupted by devices such as fast-acting valves

EngroEngro

Design dataDesign data

P & I D of ECPLP & I D of ECPL

Plant operation & ControlPlant operation & Control

• Automatic control through level of Automatic control through level of product water Tank.product water Tank.

• Manual control by selecting switches Manual control by selecting switches in the field.in the field.

Plant Start Up ,Shut Down Plant Start Up ,Shut Down conditions & Set Pointsconditions & Set Points

• pHpH

pH< 8.0 plant in normal operation.pH< 8.0 plant in normal operation.pH > 8.0 dump valve will open, high pH > 8.0 dump valve will open, high

pH alarm will initiate.pH alarm will initiate.

Water Chemistry

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