Alkalinity,hardness,softening BY Muhammad Fahad Ansari 12IEEM14

Alkalinity HardnessAlkalinity Hardnessamp LimeSoda Ash Softeningamp LimeSoda Ash Softening

BYBYMuhammad Fahad AnsariMuhammad Fahad Ansari

12IEEM1412IEEM14

General ConsiderationsGeneral Considerations

1 Its capacity to neutralize acids or its buffering capacity

2 3 major classes of materials

A Bicarbonates HCO3- - pH 40 le pH

83 B Carbonates CO3

- - gtpH 83 lt pH 10

C Hydroxide OH- - gt pH 100

Sanitary SignificanceSanitary Significance

1 LimeSoda Ash Softening1 LimeSoda Ash Softening

2 Effects on Coagulant Dosing

3 Total Dissolved Solids compliance

4 Industrial Wastes Discharges

5 Calcium Carbonate Stability

Method of AnalysisMethod of Analysis

Acrobat Document

1 Phenolphthalein Alkalinity

A Phenolphthalein indicator

B pH 83 endpoint of titration

2 Total Alkalinity

C Measures Carbonates and Hydroxide ions

A Bromcresol green or Methyl Orange indicator

B pH 45 endpoint of titration

C Measures Bicarbonates

Methods of ExpressingMethods of Expressing

1 Phenolphthalein Alkalinity as CaCO1 Phenolphthalein Alkalinity as CaCO33

P Alk = ml 002N sulfuric acid (1000ml sample) = mgL as CaCO3

2 Total Alkalinity as CaCO3

T Alk = ml 002N sulfuric acid X (1000ml sample) = mgL as CaCO3

3 Hydroxide Carbonate and Bicarbonate Alkalinity as CaCO3

Alkalinity Alkalinity RelationshipsRelationships

Titration Titration ResultResult

OHOH--

Alkalinity as Alkalinity as CaCOCaCO33

COCO33--

Alkalinity as Alkalinity as CaCOCaCO33

HCOHCO33--

Alkalinity as Alkalinity as

CaCO3CaCO3

P = 0P = 0 00 00 TT

Plt12 TPlt12 T 00 2P2P T-2PT-2P

P=12 TP=12 T 00 2P2P 00

Pgt12 TPgt12 T 2P ndash T2P ndash T 2(T- P)2(T- P) 00

P = TP = T TT 00 00

Standard SolutionsStandard Solutions

General ConsiderationsGeneral Considerations

1 Saves Time in calculating results1 Saves Time in calculating results

2 Selection of Proper Normality is convenient2 Selection of Proper Normality is convenient

1 mgml or 1000mg solution 1 mgml or 1000mg solution

1eqwt example Alkalinity as CaCO3 = 1eqwt example Alkalinity as CaCO3 = 002 N002 N

3 Preparation of Solution of Proper Normality3 Preparation of Solution of Proper Normality

Material of Known purity is weighed amp Material of Known purity is weighed amp transferred to transferred to volumetric flask volumetric flask

Purchase Solutions of known Normality Purchase Solutions of known Normality

Preparation of 1N Acid Preparation of 1N Acid SolutionSolution

Sulfuric acid used for Alkalinity Test Sulfuric acid used for Alkalinity Test

1 GMW = 98 g pure H2SO4 = 2016 g H+

1 GMW2 = 49 g pure H2SO4 = 1008 g H+

Acid is 96 pure then 49096 = 51 g = 1008 g H+

Make 5 stronger = 51 X 105 = 535 g

Procedure Weigh about 53g of conc acid into a small beaker on Trip balance Place 500 ml of distilled water in 1-liter graduated cylinderAnd add the acid to it Rinse the contents of the beaker into the cylinderWith distilled water and add water to the 1-liter mark Mix by pouringBack and forth from the cylinder into a large beaker Cool to room temp

Primary StandardPrimary Standard

Sodium Carbonate is a convenient primary standard Sodium Carbonate is a convenient primary standard

MW = 106 of Na2SO3

1EW or 1N = 53gL when reacting with H2SO4 to pH 45 T Alk endpoint

Preparation of 002 N Acid or N50 can be made from 1N based onml X N = ml X N

Example ml X 10 = 1000 X 002 ml = 20

Alkalinity and Alkalinity and hardness - what is ithardness - what is itAlkalinity a measure of the ability of a Alkalinity a measure of the ability of a water sample to neutralize strong acidwater sample to neutralize strong acidndash Expressed as mg CaCOExpressed as mg CaCO33 per liter or micro- per liter or micro-

equivalentsequivalentsndash Alkalinities in natural waters usually Alkalinities in natural waters usually

range from 20 to 200 mgLrange from 20 to 200 mgLHardness a measure of the total Hardness a measure of the total concentration of calcium and concentration of calcium and magnesium ionsmagnesium ionsndash Expressed as mg CaCOExpressed as mg CaCO33 per liter per liter

Alkalinity and Alkalinity and hardness - how to hardness - how to samplesampleUsually collected at Usually collected at the surface in lakes the surface in lakes (0 to 1m depth)(0 to 1m depth)

Keep the sample Keep the sample cool (4cool (4ooC C refrigerated) and refrigerated) and out of direct out of direct sunlightsunlight

Alkalinity and hardness- Alkalinity and hardness- why measurewhy measure

The The alkalinityalkalinity of natural waters is usually of natural waters is usually due to weak acid anions that can accept due to weak acid anions that can accept and neutralize protons (mostly bicarbonate and neutralize protons (mostly bicarbonate and carbonate in natural waters)and carbonate in natural waters)ndash Usually expressed in units of calcium Usually expressed in units of calcium

carbonate (CaCOcarbonate (CaCO33))

The ions Ca and Mg that constitute The ions Ca and Mg that constitute hardnesshardness are necessary for normal plant are necessary for normal plant and animal growth and survivaland animal growth and survival

Hardness may affect the tolerance of fish Hardness may affect the tolerance of fish to toxic metalsto toxic metals

Introduction to Introduction to HardnessHardness

Causes amp Sources of HardnessCauses amp Sources of Hardness

Cations causing Cations causing hardnesshardness

AnionsAnions

CaCa++++ HCOHCO33--

MgMg++++ SOSO44==

SrSr++++ ClCl--

FeFe++++ NONO33--

MnMn++++ SiOSiO33==

Source ndash Rain contact with soil and rock formations

Sanitary SignificanceSanitary Significance

Reasons to SoftenReasons to Soften

1 Reduce Soap Consumption1 Reduce Soap Consumption

2 Improve Aesthetics of Water2 Improve Aesthetics of Water

3 Hot Water Heaters last longer3 Hot Water Heaters last longer

Reasons not to Soften Reasons not to Soften

1 Expensive Process1 Expensive Process

2 May be less healthy2 May be less healthy

3 Competes with health related costs3 Competes with health related costs

Method of AnalysisMethod of Analysis

EDTA ndash Ethylenediaminetertraacetic Acid Method EDTA ndash Ethylenediaminetertraacetic Acid Method

EDTA complexes Ca amp Mg

Eriochrome Black T serves as an indicator when EDTA is in excess of the complexed hardness ions

Color change is from red to blue

Types of HardnessTypes of Hardness

Calcium and Magnesium Hardness Calcium and Magnesium Hardness Total Hardness ndash Calcium Hardness = Magnesium Hardness Total Hardness ndash Calcium Hardness = Magnesium Hardness

Carbonate and Noncarbonate Hardness When alkalinity lt Total Hardness CO3 Hardness = T Alkalinity

When alkalinity ge Total hardness CO3 Hardness = T Hardness

CO3 hardness removed by boiling or lime (Temporary Hardness)

Noncarbonate Hardness (permanent) = T Hardness ndash CO3 Hardness

Pseudo-Hardness Associated with Na+ which causes soap consumption but not considered part of hardness

By By

Douglas Rittmann PhD PEDouglas Rittmann PhD PEWaterWastewater ConsultantWaterWastewater Consultant

Presented toPresented to

CE 5345CE 5345

OnOn

Sept 2006Sept 2006

Effective LimeSoda Ash Effective LimeSoda Ash Water SofteningWater Softening

I IntroductionI Introduction

A Reasons to SoftenA Reasons to Soften

1 Reduce Soap Consumption1 Reduce Soap Consumption

2 Improve Aesthetics of Water2 Improve Aesthetics of Water

B Reasons not to Soften B Reasons not to Soften

1 Expensive Process1 Expensive Process

2 May be less healthy2 May be less healthy

3 Hot Water Heaters last 3 Hot Water Heaters last longerlonger

Water SofteningWater Softening

3 Competes with health related costs3 Competes with health related costs

II What is Hardness II What is Hardness

C Carbonate Hardness as CaCOC Carbonate Hardness as CaCO33 = T Alkalinity as CaCO = T Alkalinity as CaCO33

D Non-Carbonate Hardness = T Hardness ndash T Alkalinity D Non-Carbonate Hardness = T Hardness ndash T Alkalinity

Water SofteningWater Softening

a Removed by Boilinga Removed by Boiling

b Removed by Limeb Removed by Lime

a Unaffected by boilinga Unaffected by boiling

b Removed by Soda Ashb Removed by Soda Ash

B T Hardness mgL as CaCOB T Hardness mgL as CaCO33 = (Ca X 25) + (Mg X 412) = (Ca X 25) + (Mg X 412)

(MW=100) (40 X 25 = 100) (243 X 412 = 100)(MW=100) (40 X 25 = 100) (243 X 412 = 100)

A Hardness ClassificationsA Hardness Classifications

a Soft Water = 0 to 70 mgLa Soft Water = 0 to 70 mgL

b Moderate Hardness = 71 to 150 mgLb Moderate Hardness = 71 to 150 mgL

c Hard Water = gt 150 mgLc Hard Water = gt 150 mgL

Water SofteningWater Softening

III Methods of SofteningMethods of Softening

A Lime-Soda Ash ChemistryA Lime-Soda Ash Chemistry1 11 1stst Stage Treatment (Lime only) Stage Treatment (Lime only)

CO CO22 + Ca(OH) + Ca(OH)22 CaCOCaCO33 + H + H22OO

Ca + 2HCO Ca + 2HCO33 + Ca(OH) + Ca(OH)22 2CaCO2CaCO33 + 2H + 2H22O(pH 83-94) O(pH 83-94)

Mg + 2HCO Mg + 2HCO33 + Ca(OH) + Ca(OH)22 CaCOCaCO33 + Mg + CO + Mg + CO33 + 2H + 2H22O(pH gt108)O(pH gt108)

a Carbon Dioxide Removal (lt 83 pH)a Carbon Dioxide Removal (lt 83 pH)

b Carbonate Hardness Removal b Carbonate Hardness Removal

c Magnesium Hardness Removal (gtpH 108)c Magnesium Hardness Removal (gtpH 108)

Mg + CO Mg + CO33 + Ca(OH) + Ca(OH)22 CaCOCaCO33 + + Mg(OH)Mg(OH)22

Mg + SO Mg + SO44 + Ca(OH) + Ca(OH)22 Ca + SO Ca + SO44 + + Mg(OH)Mg(OH)22

Ca + SO Ca + SO44 + Na + Na22CO3 NaCO3 Na22SOSO44 + + CaCOCaCO33

2 22 2ndnd Stage Treatment Stage Treatment (Soda Ash) (Soda Ash)

Ca + Cl Ca + Cl22 + Na + Na22COCO33 CaCOCaCO33 + 2NaCl + 2NaCl

AnalysesAnalyses Water 1Water 1 Water 2Water 2 Water 3Water 3

Total HardnessTotal Hardness 300300 300300 300300

Calcium Calcium HardnessHardness

200200 200200 200200

Mg HardnessMg Hardness 100100 100100 100100

Total AlkalinityTotal Alkalinity 150150 250250 350350InterpretationsInterpretations Water 1Water 1 Water 2Water 2 Water 3Water 3

Calcium Calcium AlkalinityAlkalinity

150150 200200 200200

Mg AlkalinityMg Alkalinity NoneNone 5050 100100

Sodium Sodium AlkalinityAlkalinity

NoneNone NoneNone 5050

Ca NC Ca NC HardnessHardness

5050 NoneNone NoneNone

Mg NC Mg NC HardnessHardness

100100 5050 nonenone

A Calcium Alkalinity = Ca Hardness or T Alkalinity whichever is smallerA Calcium Alkalinity = Ca Hardness or T Alkalinity whichever is smaller

B1 Magnesium Alkalinity = Mg Hardness if T Alkalinity gt or = than total hardnessB1 Magnesium Alkalinity = Mg Hardness if T Alkalinity gt or = than total hardness

B2 Magnesium Alkalinity = Total Alkalinity ndash calcium hardness if total alkalinity is gt thanB2 Magnesium Alkalinity = Total Alkalinity ndash calcium hardness if total alkalinity is gt than calcium hardness but less than total hardnesscalcium hardness but less than total hardness

C Sodium alkalinity = total alkalinity ndash total hardnessC Sodium alkalinity = total alkalinity ndash total hardness

IV Chemical Analyses InterpretationsIV Chemical Analyses Interpretations

D NCH = Total Hardness ndash Total Alkalinity ( If Mg Alkalinity present then no Ca NCH)D NCH = Total Hardness ndash Total Alkalinity ( If Mg Alkalinity present then no Ca NCH)

Water SofteningWater Softening

Example Calculate the hydrated lime (100) soda ash and carbon dioxide requirement to Example Calculate the hydrated lime (100) soda ash and carbon dioxide requirement to Reduce the hardness of a water with the following analysis to about 50 to 80 mgL by the excessReduce the hardness of a water with the following analysis to about 50 to 80 mgL by the excessLime-soda ash processLime-soda ash process

Analyses Total Hardness = 280 mgL as Analyses Total Hardness = 280 mgL as CaCO3CaCO3 Mg++ = 21 mgL Mg++ = 21 mgL Alkalinity = 170 mgL as CaCO3Alkalinity = 170 mgL as CaCO3 Carbon Dioxide = 6 mgLCarbon Dioxide = 6 mgL

Lime Requirement Carbon Dioxide = (6) (56) (44) = 8 Lime Requirement Carbon Dioxide = (6) (56) (44) = 8 Alkalinity = (170) (56) (100) = 95 Alkalinity = (170) (56) (100) = 95 Mg ++ = (21) (56) (243) = 48Mg ++ = (21) (56) (243) = 48

Excess Lime = = 35Excess Lime = = 35 Total CaO required = Total CaO required = 186mgL186mgL

Soda Ash Requirement NCH = 280 ndash 170 = 110 mgLSoda Ash Requirement NCH = 280 ndash 170 = 110 mgL Soda Ash (Na2CO3) = (110) (106) (100) = Soda Ash (Na2CO3) = (110) (106) (100) = 117 mgL117 mgL

A Theoretical Solubility of Ca amp Mg A Theoretical Solubility of Ca amp Mg Mg(OH)2 = 9 mgL SolubilityMg(OH)2 = 9 mgL Solubility CaCO3 = 17 mgL SolubilityCaCO3 = 17 mgL Solubility Total = ~ 26 mgL SolubilityTotal = ~ 26 mgL Solubility

B Practical Minimum Total Hardness = 50 to 80 mgLB Practical Minimum Total Hardness = 50 to 80 mgL

V Theoretical versus PracticalV Theoretical versus Practical

Water Treatment Water Treatment ChemistryChemistry

Water SofteningWater Softening 2929

Water SofteningWater Softening

Hardness is an important water quality parameter in Hardness is an important water quality parameter in determining the suitability of water for domestic and determining the suitability of water for domestic and industrial usesindustrial usesndash Hard waters require considerable amounts of soap to produce Hard waters require considerable amounts of soap to produce

foamfoamndash Hard waters produce scale in hot-water pipers heaters and Hard waters produce scale in hot-water pipers heaters and

boilersboilers

CaCa2+2+ + 2HCO + 2HCO33-- CaCO CaCO33 (s) + CO (s) + CO22 (g) + H (g) + H22OO

Groundwater is generally harder than surface waterGroundwater is generally harder than surface water Principal cations causing hardness and the major Principal cations causing hardness and the major

anions associated with them (in decreasing order of anions associated with them (in decreasing order of abundance in natural waters) abundance in natural waters) ndash Cations CaCations Ca2+2+ Mg Mg2+2+ Sr Sr2+2+ Fe Fe2+2+ Mn Mn2+2+

ndash Anions HCOAnions HCO33-- SO SO44

2-2- Cl Cl-- NO NO33-- SiO SiO33

2-2-

Water Treatment Water Treatment ChemistryChemistry

Water SofteningWater Softening 3030

Water HardnessWater Hardness Hardness expressed in mgL as CaCOHardness expressed in mgL as CaCO33

Methods of determinationMethods of determinationndash Calculation (see example)Calculation (see example)

Hardness (mgL) as CaCOHardness (mgL) as CaCO33 = M = M2+2+ (mgL) x 50 EW of M (mgL) x 50 EW of M2+2+

ndash EDTA titrimetric methodEDTA titrimetric methodMM2+2+ + Eriochrome Black T (blue) + Eriochrome Black T (blue) (M middot Eriochrome Black T) (M middot Eriochrome Black T)complex complex (wine red)(wine red)

Water softening is needed when hardness is above 150-Water softening is needed when hardness is above 150-200 mgL Hardness 50-80 is acceptable in treated 200 mgL Hardness 50-80 is acceptable in treated waterwater

mgL CaCO3

Degree of hardness

0-75 75-150 150-300 300 up

Soft Moderately hard Hard Very hard

Lime-Soda [Ca(OH)Lime-Soda [Ca(OH)22-Na-Na22COCO33] ] Process Process Recarbonation by bubbling CORecarbonation by bubbling CO22 after after softeningsoftening

Recarbonation is usually required after Recarbonation is usually required after lime-soda processlime-soda process

WhyWhyndash To prevent super-saturated CaCOTo prevent super-saturated CaCO33 (s) and Mg(OH) (s) and Mg(OH)22

(s) from forming harmful deposits or undesirable (s) from forming harmful deposits or undesirable cloudiness in water at a later timecloudiness in water at a later time

CaCOCaCO33 (s) + CO (s) + CO22 + H + H22O O Ca Ca2+2+ + 2HCO + 2HCO33--

MgCOMgCO33 (s) + CO (s) + CO22 + H + H22O O Ca Ca2+2+ + 2HCO + 2HCO33--

ndash To neutralize excessively high pH caused by To neutralize excessively high pH caused by NaNa22CO3CO3

OHOH-- + CO + CO22 HCO HCO33--

Lime - Soda Ash Lime - Soda Ash SofteningSoftening AdvantagesAdvantages 1048708 1048708 potential for significantly reducing totalpotential for significantly reducing total

dissolved solidsdissolved solids 1048708 1048708 removes hardnessremoves hardness 1048708 1048708 lime added to process is removed lime added to process is removed

precipitates soluble iron and precipitates soluble iron and manganese (groundwater)manganese (groundwater)

1048708 1048708 disinfectiondisinfection 1048708 1048708 aids in coagulationaids in coagulation

Lime - Soda Ash Lime - Soda Ash SofteningSoftening

DisadvantagesDisadvantages 1048708 1048708 large quantities of sludgelarge quantities of sludge 1048708 1048708 sodium remains after adding sodium remains after adding

soda ashsoda ash

(however hardness removed by (however hardness removed by soda ash is usually a small soda ash is usually a small percentage of total hardness)percentage of total hardness)

A Reasons to SoftenA Reasons to Soften

1 Reduce Soap Consumption1 Reduce Soap Consumption

2 Improve Aesthetics of Water2 Improve Aesthetics of Water

B Reasons not to Soften B Reasons not to Soften

1 Expensive Process1 Expensive Process

2 May be less healthy2 May be less healthy

3 Hot Water Heaters last 3 Hot Water Heaters last longerlonger

Water SofteningWater Softening

3 Competes with health related costs3 Competes with health related costs

AnalysesAnalyses Water 1Water 1 Water 2Water 2 Water 3Water 3

Total HardnessTotal Hardness 300300 300300 300300

Calcium Calcium HardnessHardness

200200 200200 200200

Mg HardnessMg Hardness 100100 100100 100100

Total AlkalinityTotal Alkalinity 150150 250250 350350InterpretationsInterpretations Water 1Water 1 Water 2Water 2 Water 3Water 3

Calcium Calcium AlkalinityAlkalinity

150150 200200 200200

Mg AlkalinityMg Alkalinity NoneNone 5050 100100

Sodium Sodium AlkalinityAlkalinity

NoneNone NoneNone 5050

Ca NC Ca NC HardnessHardness

5050 NoneNone NoneNone

Mg NC Mg NC HardnessHardness

100100 5050 nonenone

A Calcium Alkalinity = Ca Hardness or T Alkalinity whichever is smallerA Calcium Alkalinity = Ca Hardness or T Alkalinity whichever is smaller

B1 Magnesium Alkalinity = Mg Hardness if T Alkalinity gt or = than total hardnessB1 Magnesium Alkalinity = Mg Hardness if T Alkalinity gt or = than total hardness

B2 Magnesium Alkalinity = Total Alkalinity ndash calcium hardness if total alkalinity is gt thanB2 Magnesium Alkalinity = Total Alkalinity ndash calcium hardness if total alkalinity is gt than calcium hardness but less than total hardnesscalcium hardness but less than total hardness

C Sodium alkalinity = total alkalinity ndash total hardnessC Sodium alkalinity = total alkalinity ndash total hardness

IV Chemical Analyses InterpretationsIV Chemical Analyses Interpretations

D NCH = Total Hardness ndash Total Alkalinity ( If Mg Alkalinity present then no Ca NCH)D NCH = Total Hardness ndash Total Alkalinity ( If Mg Alkalinity present then no Ca NCH)

Water SofteningWater Softening

Example Calculate the hydrated lime (100) soda ash and carbon dioxide requirement to Example Calculate the hydrated lime (100) soda ash and carbon dioxide requirement to Reduce the hardness of a water with the following analysis to about 50 to 80 mgL by the excessReduce the hardness of a water with the following analysis to about 50 to 80 mgL by the excessLime-soda ash processLime-soda ash process

Analyses Total Hardness = 280 mgL as Analyses Total Hardness = 280 mgL as CaCO3CaCO3 Mg++ = 21 mgL Mg++ = 21 mgL Alkalinity = 170 mgL as CaCO3Alkalinity = 170 mgL as CaCO3 Carbon Dioxide = 6 mgLCarbon Dioxide = 6 mgL

Lime Requirement Carbon Dioxide = (6) (56) (44) = 8 Lime Requirement Carbon Dioxide = (6) (56) (44) = 8 Alkalinity = (170) (56) (100) = 95 Alkalinity = (170) (56) (100) = 95 Mg ++ = (21) (56) (243) = 48Mg ++ = (21) (56) (243) = 48

Excess Lime = = 35Excess Lime = = 35 Total CaO required = Total CaO required = 186mgL186mgL

Soda Ash Requirement NCH = 280 ndash 170 = 110 mgLSoda Ash Requirement NCH = 280 ndash 170 = 110 mgL Soda Ash (Na2CO3) = (110) (106) (100) = Soda Ash (Na2CO3) = (110) (106) (100) = 117 mgL117 mgL

A Theoretical Solubility of Ca amp Mg A Theoretical Solubility of Ca amp Mg Mg(OH)2 = 9 mgL SolubilityMg(OH)2 = 9 mgL Solubility CaCO3 = 17 mgL SolubilityCaCO3 = 17 mgL Solubility Total = ~ 26 mgL SolubilityTotal = ~ 26 mgL Solubility

B Practical Minimum Total Hardness = 50 to 80 mgLB Practical Minimum Total Hardness = 50 to 80 mgL

V Theoretical versus PracticalV Theoretical versus Practical

Pb Result of chemical analysis of a sample of raw Pb Result of chemical analysis of a sample of raw water is given belowwater is given below

Ca++=80mglCa++=80mglNa+=25 meqlNa+=25 meqlTotal alkalinity=80mglTotal alkalinity=80mglTotal hardness=120mglTotal hardness=120mglSO-4=20mglSO-4=20mglCl-=140mglCl-=140mglNO3-=5mglNO3-=5mglPrepare bar chart program of raw waterPrepare bar chart program of raw waterEstimate the quantity in kgday of CaO(90) and Estimate the quantity in kgday of CaO(90) and

Soda ash as (95 ) to softener 4 million liters of Soda ash as (95 ) to softener 4 million liters of this waterthis water

Ion Exchange

Ion exchange is an adsorption phenomenon

where the mechanism of adsorption is

electrostatic Electrostatic forces hold ions to

charged functional groups on the surface of the

ion exchange resin The adsorbed ions replace

ions that are on the resin surface on a 11 charge

basis For example

Applications of ion exchange in water amp wastewater

bull Ca Mg (hardness removal) exchange with Na or H

bull Fe Mn removal from groundwater

bull Recovery of valuable waste products Ag Au U

bull Demineralization (exchange all cations for H all

anions for OH)

bull Removal of NO3 NH4 PO4 (nutrient removal)

Ion Exchangers (types)

bull Natural Proteins Soils Lignin Coal Metal

oxides Aluminosilicates (zeolites)

(NaOAl2O34SiO2)

bull Synthetic zeolite gels and most common -

polymeric resins (macroreticular large pores)