2.Pre Treatment

8/19/2019 2.Pre Treatment

1/41

WATER TREATMENT INA POWER PLANT

•External Treatment–Pre Treatment

–Softening/Demineralization/Degassing

•Internal Treatment–

Condensate olis!ing–Ox"gen Treatment

–De aeration/ #"drazine Dozing

–P!os!ate Dozing


2/41

MET#ODOLO$IES %OR WATERTREATMENT

• PRE TREATMENT– C!lorination

– Sedimentation

– %iltration

– Coag&lation and %lo''&lation– A'ti(ated 'ar)on *lter

+, SO%TENIN$+, Soda lime ro'ess

-, Lime.)ase ex'!ange softener

, 0lend softener


3/41

-, E1OPORATION

, DEMINERALISATION

2, DE$ASSIN$3, MEM0RANE PROCESSES

-, RE1ERSE OSMOSIS

, 4LTRA %ILTRATION

2, ELECTRO DIAL5SIS

MET#ODOLO$IES %ORWATER TREATMENT


4/41

OR$ANICS

- Deri(es from de'omosing(egeta)le matter

- Most imortant 'onstit&ent is a

gro& of large 6ee7l" a'idi'mole'&les 'alled as !&mi' a'ids

- Man" of t!em are

ol"ele'trol"tes- $i(e 6ater "ello6 to )ro6n

'olo&r


5/41

OR$ANICS

8, %o&l anion resin in t!ree7inds,

8, S&rfa'e 'oating interfering

6it! rate of rea'tion+, Loss of 'aa'it" d&e to t!e

a'ti(e sites in t!e resin areeit!er ermanentl" o''&ied

)" organi's or t!e oresleading to t!em !a(e )een)lo'7ed

-, Arrests 'a&sti' soda d&ringregeneration,


6/41

COPIN$ WIT#

OR$ANICS8, Lea(e t!em and s&9er t!e

'onse:&en'es

+, 4se oro&s resins eit!er as6or7ing resin or a)sor)ers

-, Remo(e !&mi' a'ids in a re.

treatment lant,


7/41

COLLOIDS

- 4s&all" 'la" arti'les &to ;,+mi'ron size,

-0iggest !&mi' a'ids are also6it!in 'olloidal size,

- 0&ild & an inert 'oating on ionex'!ange resins )" s&rfa'e for'es

- Remo(ed )" 'oag&lation<=o''&lation< &sing 'oag&lationaids


8/41

S4SPENDED MATTER

- Coarse &ndissol(ed arti'les

- A''&m&lates on ion ex'!angeresins

- Leads to !ig! ress&re loss<

red&'ed t!ro&g!&t me'!ani'aldamage to resin

- C!emi'al erforman'e of t!eresin is also a9e'ted

- Ma7ing )a'7 6as! more di>'&lt

- Remo(ed )" sedimentation<*ltration


9/41

NON REACTI1E SILICA

- Also 'alled as 'olloidal sili'a- C!emi'all" inert< not remo(ed )"

ion ex'!ange

-

Di>'&lt to ded&'t )" anal"sis- In !ig! ress&re )oilers t!is

)rea7s do6n to li)erate normalsili'a

- So&r'e is from dead mi'ro.organisms< a'ti(ated sili'atreatment


10/41

COM0INED IRON

- Aears as ordinar" s&sendedoxide

- Some times it 'an )e asso'iated

6it! organi' matter- Passes t!ro&g! 'ation ex'!anger

)&t ta7en & on anion resin

- Ca&sti' regenerant )rea7s t!e iron'omlex and lea(es a ferri'!"droxide sl&dge fo&ling t!e resin,


11/41

C#LORINATION

- %or t!e remo(al of li(ing mi'roorganisms to sto t!em)reeding in t!e treatment lant

Cl+ ? #+ O #Cl ? #OCl

#OCL # ? ? OCL

@#"o'!lorite

Ion


12/41


13/41

SEDIMENTATION

- Remo(al of =o'7 )"gra(itational for'es

TERMINAL 1ELOCIT5 B [email protected]

8&

g .$ra(itational 'onstant

d Parti'le diameter

@s.8. Parti'le Densit" Densit" of6ater

4 .inemati' 1is'osit"


14/41


15/41


16/41


17/41

COA$4LATION

•A ro'ess in 6!i'! smallarti'les in s&sension Fointoget!er to form largeragglomerates


18/41

WA5S TO PROMOTE

COA$4LATION• To ne&tralise or re(erse t!e

ele'tri'al re&lsion e9e't )"

8, Introd&'ing fres! arti'les 6it!a ositi(e '!arge

+, Adding tra'es of s&rfa'e a'ti(ematerials 'alled 'oag&lation

aids,


19/41

COA$LATION AIDS

. Long '!ain mole'&les<'arr"ing ele'tri'all" a'ti(egro&s all along t!e lengt!of t!e '!ain


20/41

POL5ACR5LAMIDE

- Carr" ositi(e '!arges setreg&larl" along a long t!read

li7e mole'&le- P&rose made to !a(e long

'!ains and are e9e'ti(e at

dozes )elo6 8 m- Toxi'< exensi(e


21/41

SA%E NAT4RAL MATERIALS

- Potato star'!

- A'ti(ated sili'a @ol"sili'i'

a'id- Dozed 8; times more t!an

ol"a'r"lamide

-Possi)ilit" of lea(ing !ig!ol"mers of sili'a 6!i'! a't asnon rea'ti(e sili'a


22/41

AD1ANTA$ES O% 4SIN$COA$4LATIN$ AIDS/

POL5ELECTROL5TES8, Red&'e (ol&me of sl&dges@2; to

G;H

+, Sl&dge 'ontain less 6ater and 'an)e easil" de6atered

-, # of t!e sol&tion is not a9e'ted

, Do not add to TDS2, Carr"o(er of sol&)le Iron

Al&mina are eliminated


23/41

DISAD1ANTA$ES

8, Exensi(e

+, Resid&als 6ill fo&l t!e resinli7e !&mi' a'ids

-, Toxi'

, %ormation of non rea'ti(esili'a @ossi)ilit"

2, Side e9e'ts of resid&als ormore di>'&lt to redi't


24/41

%LOCC4LATION

Al@SO- ? 3 #+ O +Al@O#- ? -#+ SO

%L4%%5 %LOC

WIT# LAR$ES4R% ACE AREA

CARR5IN$POSITI1E

C#AR$E


25/41

D4AL P4RPOSE SER1ED 05

%LOCC4LATION- More e9e'ti(e t!an 'oag&lation

aids as it 'reates (er" large

Ele'tro ositi(e area in 6ater- $reatl" in'reases t!e

'on'entration of arti'les in

6ater and t!erefore in'reasest!e n&m)er of 'ollisions ta7ingla'e


26/41

REJ4IREMENTS

- Pre'iitation 6ill ta7e la'e onl"6it!in 'ertain range of # (al&es

- $ood mixing and time at lo6'on'entrations

- %a(o&red )" n&'lei on 6!i'! t!ere'iitate 'an form

- Iron re'iitate at # 2.3

-

Al&mini&m re'iitate at # 3.K- Sodi&m al&minate re'iitate at #


27/41


28/41


29/41


30/41

SAND %ILTERS

•$ra(it" %ilters–#ig! Initial Cost

–Lo6 Oerating Cost

–Lo6 %lo6 Rate

–Lo6 #ead Loss

–Con'rete Str&'t&re


31/41

SAND %ILTERS

•Press&re %ilters–Lo6 Initial Cost

–#ig! Oerating Cost

–#ig! %lo6 Rate

–Steel Tan7

PRESS4RE SAND


32/41

PRESS4RE SAND%ILTER

• 1essel !olding a )ed

of *ne gran&larmedi&m s&'! assand

• %orming man"'!annels )et6eengran&les

• Contains

–$raded $ra(el 8,;mmto+2mm

– $raded sand ;,2mmto 8,;mm


33/41


34/41


35/41


36/41


37/41


38/41


39/41


40/41


41/41

Documents

2.Pre Treatment