Presentation - Water Treatment

8/11/2019 Presentation - Water Treatment

1/48

Please Keep your mobiles

on silent


2/48

An Introduction To Water Treatment

By

Jayadevi.V.D- WWS


3/48

HIGHLIGHTS

WATER CHEMISTRY WATER IMPURITIES

VARIOUS SOLUTION OFFERED RAW WATER PRETREATMENT PLANT

DEMINERALISATION PLANT

SOFTENER PLANT

REVERSE OSMOSIS PLANT

SIDE STREAM FILTRATION/CW DOSING

CONDENSATE POLISHING UNIT


4/48

WATER MOLECULE


5/48

Hydrogen Bonding Water Vapour Has Got High Energy

Content High Surface Tension Water is a Universal Solvent

Pure Water Is An Insulator Osmosis Viscosity

Characteristics Of

Water Molecule


6/48

A Typical Water CircuitDiagram

SEWAGE

WATER

TREATMENT

AT HOMES

OFFICES etc.

MUNICIPAL

TREATMENT

DRINKING

WATER

BOILER

BLOWDOWN

.

BOILER FEED

WATER

PROCESS

CONDENSATE

PROCESS

WATER

C.T.

BLOWDOWN

COOLING

WATER

INDUSTRIAL

WATER

WATER SOURCE

EFFLUENT TREATMENT PLANT

DISCHARGE / REUSE


7/48

Why Water Treatment

Boiler for Prevention of scaling/corrosion

Prevention of stress corrosion cracking

Prevention of steam contamination

To

Increase heat transfer

Lower fuel/chemical consumption


8/48

WATER IMPURITIES


9/48

WATER IMPURITIES


10/48

Various Solutions Offered. Raw Water Treatment / Clarification / Pretreatment.

Filtration

Water Softening.

De-Mineralization.

Reverse Osmosis.

Condensate Polishing.

Tertiary Treatment.

Effluent Treatment. Sewage Treatment.

Waste Water Recycling.


11/48

PRIMARY TREATMENT


12/48

Sedimentation

Separation of suspended particles, heavierthan water by gravitational settling.

Efficiency can be increased by the use ofbasic coagulants e.g. Alum, PAC, FeCl3etcor coagulant aids if required.

Settling velocity can also be increased byincreasing the surface area of the basin.


13/48

Conventional Clariflocculators

Commonly used equipment giving good performance In case of

high flow rates to be provided in multiples Requires large areas


14/48

Removal Of Suspended Impurities

By Filtration

Pressure Sand Filters

Dual Media filters

Iron Removal filters

High Rate filters

Activated Carbon Filters


15/48

Pressure Sand Filters

Most Conventional Filters & extensively used Graded Sand

Top Most Layer With Fine Sand (16 X 32 Mesh)

Design Parameters Max. Service Velocity 10 m/hr

Backwash Velocity With Air Scouring 24 m/hr

Backwash Velocity Without Air Scouring 36m/hr

Air Flow Velocity 36 m/hr @ 2.5 mwc


16/48

Dual Media Filters

Functionally Same as PSF

300 mm layer of coarse anthracite on top of 300 mmlayer of fine sand

Advantage of DMF over PSF Coarse anthracite layer removes most of the

turbidity

The dirt holding capacity is higher than that of PSF. No separate backwashing facilities are required.


17/48

High Rate Filters

Used For Removal of Iron Scale From Mill ScaleWater

Sand Media With larger Particle Size (2 - 3 mm)

Deeper Sand Beds Than Conventional Filters (1.8- 2.0 m)


18/48

Activated Carbon Filters

Application For Dechlorination

For Removal of Organics

For removal of Odour

For Oil Removal In Condensate Polishing

Plants


19/48

TDS Reduction

Scheme Selection For Removal Of

Dissolved Impurities

SOFTENER

HARDNESSREDUCTION

SPLIT STREAMDEALKALISER

PARTIALDEMINERALISATION

SAC-DGT-WBA-SBA

M.ALKALINITY > 50 ppm

SAC-DGT-SBA

M.ALKALINITY < 50 ppm

CONDUCTIVITY10 - 30

microS/cm

DM PLANT +MB

POLISHER

CONDUCTIVITY< 1 microS/cmSiO2 < 0.2 ppm

IONEXCHANGE

SYSTEM

TDS 500 ppm

DEMINERALISATION

HIGH PRESSURECONDENSATE

LOW PRESSUREPROCESS CONDEN

CONDENSATEPOLISHING

TDSREDUCTION


20/48

Water Chemistry - Definitions

Ion - An Atom In Solution Carrying An IntegralElectrical Charge, Either Positive Or Negative.

Ionization - The Formation Of Ions When AnElectrolyte Is Dissolved In Water. The Effect OfDissociaton Or Separation Of Ions Of ACompound By A Liquid Of High DielectricConstant Such As Water.

Atomic Weight- Relative Weight Of An Element


21/48

Molecular Weight- The Sum Of The Weights Of The Atoms Of A Molecule

Cation- A Positively Charged Ion Resulting From Dissociation Of MoleculesIn Aqueous Solution

Anion - Negatively Charged Ion Resulting From Dissociation Of Molecules InAqueous Solution

Acid - A Compound Which Dissociates To Furnish Hydrogen Ions In WaterSolution

Alkalinity - The Quantitative Ability Of Aqueous Media To React WithHydrogen Ions.

Total Alkalinity-Amount Of Titratable Bicarbonates, Carbonates & HydroxideIons At A Ph End Point Of 4.5

Hardness - Total Concentration Of Calcium And Magnesium Ions.

Temporary Hardness- Hardness Associated With Alkalinity

Permanent Hardness- Hardness Associated With Ema

Water ChemistryDefinitions Contnd


22/48


23/48

Ion Exchange Resins

CATION ANION

SAC WAC SBA WBA

TYPE 1 TYPE 2


24/48

Characteristics Of Ion Exchange

Resins

Skeleton Like Plastic Structure

Insoluble In Water

Large Ion Which Is Electrically Charged AndHolds Ions Of Opposite Charge

Cation Resin - Negatively Charged

Anion Resin - Positively Charged

C i i Of


25/48

Resin Beads Are Porous And Permeable In Nature Resins Are Hydrophobic And Functional Groups

Are Hydrophilic

Size Of The Beads - 20 - 40 Mesh (0.8 - 0.4 mm)

Normality Cation resin - 2

Anion Resin - 1.3 Basic Monomers - VB & DVB

Functional Groups SAC - SO3H

WAC - COOH

SBA - Quaternary Amines

WBA - Sec. & Tertiary Amines

Characteristics Of Ion Exchange

ResinsContnd


26/48

WAC Alkaline Hardness ie., Ca & MgCarbonates And Bicarbonates

Straight SAC Ca+Mg+Na+Other Metals If Present

SAC After WAC Permanent Hardness +Na

WBA EMAStraight SBA EMA+Silica+CO2 Leakage From

Degasser

SBA after WBA Silica+EMA Slip For WBA (EMA slipFrom WBA Will Correspond To Na

slip From Cation Unit)MB Na & SiO2 Slip From Preceding

Cation And Anion Units

Scheme Selection


27/48

When Is RO Used ?

High Feed Water TDS

Brackish Water

Sea Water

Effluent Recycle

As An Alternative To DM


28/48

Reverse Osmosis

Principles Of RO

Ro Membrane - Types & Terminology

System Configuration & Design Criteria

Factors Affecting RO Performance

R.O - Applications Plant Engineering Aspects


29/48

What Is Reverse Osmosis ?

Osmotic Flow Osmotic Equilibrium

Osmotic

Head

Pure Water

Salt Solution

Semipermeable

Membrane


30/48


31/48

Types of Membranes

Micro Filtration (MF)

Ultra Filtration (UF)

Nan Filtration (NF)

Reverse Osmosis (RO)


32/48

Membranes - Pore Sizes

RO Membrane : 0.003 to 0.001 Microns

UF Membrane : 0.01 to 0.02 Microns

MF Membrane : 0.1 to 50 Microns


33/48

Ro Membrane Types

Tubular Type

Plate & Frame Type

Hollow Fibre Type

Spiral Wound Type

C S i f


34/48

Cross-Section of

Spiral Wound Membrane

Mesh Spacer

Permeate Carrier

Membrane

O Ring

Permeate Tube

Membrane Backing

Outer Cover


35/48


36/48

Spiral Wound Elements

Types:

ULP Elements (Low Rejection)

HR Elements ( 600 psi)

XR Elements (600 psi)

Sea Water Elements (1000 psi)


37/48

75 micrometer

115 micrometer

0.2 micrometerPolyamide

Polysulfone

UltrathinMembrane Layer

Polysulfone

Support Layer

Reinforcing

Fabric

Thin-film Composite Membranes


38/48


39/48

RO - Terminology

Recovery (or Conversion) :

Permeate flow (m3/Hr)

Feedwater flow (m3/Hr)

Salt Rejection :

Permeate TDS (mg/lit)

Feedwater TDS (mg/lit)

Recovery% =

% Salt Rejection = 1 -

X 100

x 100


40/48

RO Terminology

FLUX :

Unit Flow Of Water Through A Unit Area Of MembranePer Unit Time

Permeate Flow (gallons/day)Membrane Area (ft2)

FLUX (GFD) =


41/48

Typical Operating Recoveries

FEED WATER RECOVERY

(%)

Brackish Water 75% TO 90%

Sea Water 30 TO 40%

Treated Effluent (Recycle) 60 TO 80%


42/48

RO TERMINOLOGY

Banks:Number Of Parallel Sets Of Tubes

BANK - IBANK - II

- Two Bank

III III

- Three Bank

- Single Bank


43/48

RO - Feed Limitations

PARAMETER LIMITING VALUE

TURBIDITY < 1 NTU

SDI < 5

OIL & GREASE NIL

HEAVY METALS < 0.1 (Dissolved)

CHLORINE /OXNTS NIL

pH 4 - 11

TEMPERATURE 45 DEG C MAX


44/48

RO - System Design Inputs

Feed Water Source

Feed Water Analysis

Feed water temperature

Fouling Potential Of Water

Treated Water Quality

Recovery %


45/48

Steps In RO Design

Feed Water Ionic Balance

Chemical Dosage Calculation For LSI /Scaling Control

No Of Elements= Flow /(Flux * Area) No Of Banks/Array Based On % Rec

Selection Of Element Model Based On Appln &

Treated Water Quality


46/48

Factors Affecting RO Performance

Feed Temperature :-Temp Increase >> Outlet TDS, FD-Press

-Temp Decrease >> Outlet TDS, FD-Press

Feed TDS :

-TDS Increase >> Outlet TDS, FD.Press

-TDS Decrease >> Outlet TDS,FD.Press

Increase In Feed Water Constituents (With LowerSolubilitiy Limits)


47/48

RO Plant

Pressuretube mounting

Feed header

Control valve


48/48

Thank You .

Presentation - Water Treatment

Documents

Transcript of Presentation - Water Treatment