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.
Physical StatePhysical State
• 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.
Physical StatePhysical State
• 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.
Physical StatePhysical State
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
Physical propertiesPhysical properties
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
Physical propertiesPhysical properties
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 CHEMISTRYWATER CHEMISTRY
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)
WATER CHEMISTRYWATER CHEMISTRY
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:
SOFTENING THROUGH ION SOFTENING THROUGH ION EXCHANGEEXCHANGE
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)
SOFTENING THROUGH ION SOFTENING THROUGH ION EXCHANGEEXCHANGE
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:
SOFTENING THROUGH ION SOFTENING THROUGH ION EXCHANGEEXCHANGE
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
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.
REVERSE OSMOSISREVERSE OSMOSIS
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
Elements Units 1 2 3 4 5
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
Elements Units 1 2 3 4 5
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
3 After Acid Addition
Elements Units 1 2 3 4 5
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
2 After Acid Addition
3 Product Water
Elements Units 1 2 3 4 5
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.