Nanofiltration in Water Supply Systems

8/18/2019 Nanofiltration in Water Supply Systems

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NANOFILTRATION IN WATER

SUPPLY SYSTEMS



Generally, thereare four typesof membraneprocesses,

Microltration. Ultraltration. Nanoltration.

Reverse

MEMBRANE

RO!E""E"



#ilter type "ymbol

ore"i$e, m

Operatin%ressure,

psi

&ypes ofMaterialsRemove'

Microflter MF 1.0-0.01 <30 Clay, bacteria,

large viruses,suspended solids

Ultraflter UF 0.01-0.001 20-100 iruses, proteins,

starc!es,colloids, silica,organics, dye, "at

#anoflter #F 0.001-0.0001

$0-300 %ugar, pesticides,!erbicides,

divalent anions

&everse

's(osis

&' < 0.0001 22$-1,000 Monovalent salts



)pplications o" Micro- and Ultrafltration* Conventional +ater treat(entreplace all processes eceptdisin"ection.

/retreat +ater "or &.' and

nanofltration. ronManganese re(oval a"teroidation.

&e(oval o" / precursors.

)pplications o" &.'. and nanofltration* &.'. application (ostly desalination. #anofltration frst developed to

re(ove !ardness.



()"&OR* O# NANO#)+&RA&)ON

uring 1450s &' (e(branes +it! greater

operating pressures +as developed.

6!is resulted in considerable increase in

energy cost.

6!us, lo+-pressure &' (e(branes +ere

developed and ca(e to be 7no+n as #F

(e(branes.

y t!e second !al" o" 1480s,#F beca(e

establis!ed.



NEE #OR NANO#)+&RA&)ON

ncreasing de(and o" good 9uality

+ater due to increasing population.

&educing t!e +astage and reuse o"

+ater.

etter reliability and durability o"

flter (e(branes.

6o reduce t!e overall cost o"



Materials used in #F (e(branes

•

i:erent poly(ers used arepolyet!ersul"one, polysul"one,

polyp!enylsul"one, polytetra;uoroet!ylene,

polyvinylidene ;uoride, polyacrylonitriles,

nylon, polypropylene, cellulose acetate C),

regenerated cellulose, and co(posites.• Cera(ic and cintered (etals.

• carbon nanotubes.



6+o types o" (e(branes*i. %piral (e(branes* C!eapest, (ore

sensitive to pollution.ii. 6ubular (e(branes* Most used, not

easily polluted.

ut sur"ace area o" spiral (e(branes isgreater t!an t!at o" tubular (e(branesand !ence greater capacity.



Benets of Nanoltration

o+ cost o" operation.

o+ energy cost.

o+er disc!arge and less +aste +ater

t!an typical &everse 's(osis syste(.

&eduction o" =eavy Metals re(oves

4$>.

&eduction o" +ater !ardness.

&eduction &e(oval o" viruses, bacteria,

'C?s, and /esticides.



&eduction o" #itrates and %ulp!ides.

&eduction o" t!e salt content brac7is!

+ater.

C!e(ical - Free fltration #o use o" salt.p= o" t!e +ater can be altered "or better

!ealt!.

deal "or (unicipal +ater supply, +ell

+ater, river and rain +ater.

&e(oves ron, i(e and ot!er proble(



istinct properties of

Nanoltration 6!e pore siAe o" a #F (e(brane

corresponds to a (olecular +eig!t cut-o:

o" 300-$00g(ol. =ence, separation o"

t!ese co(ponents "ro( !ig!er (olecular

+eig!t co(ponents can be ac!ieved.

#anofltration (e(branes !ave a slig!tly

c!arged sur"ace. 6!e di(ensions o" pores

are close to di(ensions o" ions and !ence



6+o basic types o" eclusion

(ec!anis(s*

1. %teric eclusion (ec!anis(*

si(ilar to sieving. Beo(etric

eclusion o" solute particles

larger t!an pore siAe.

2. C!arge based eclusion

(ec!anis(s*

i. onnan eclusion* ue to

c!ar ed nature o" #F



arious )pplications*

1. ndustrial applications*

•

Food and dairy sector.

• edible oil processing sector.

• /etroleu( industry.

• rug industry.

• /aper pulp industry

2. ater treat(ent.

3. esalination o" +ater.

D. ater so"tening. #Eapp.doc

http://d/3.Personal/Fincy%20Seminars/New%20folder%20(2)/civil/LINK/app.docx

http://d/3.Personal/Fincy%20Seminars/New%20folder%20(2)/civil/LINK/app.docx



ra-bacs of the process of

Nanoltration/

1. Me(brane "ouling.2. nsuGcient separation.

3. 6reat(ent o" concentrates.

D. Me(brane li"eti(e and c!e(ical resistance.

$. nsuGcient reHection "or individual

co(ponents.



6!ere are various +ays to reduce t!e

"ouling suc! as* /eriodic pulsing o" "eed.

/eriodic pulsing fltrate

bac7+as!ing.

ncreasing s!ear by rotating

(e(brane.

ibrating (e(brane.



/retreat(ent.

/retreat(ent o" "eed +ater greatly

in;uences t!e per"or(ance o" #F

installations.

6!e application o" a pre-treat(ent !as

several benefts* Me(branes !ave a longer li"e-span

+!en pre-treat(ent is per"or(ed.

6!e production ti(e o" t!e installationis etended.

6!e (anage(ent tas7s beco(e

si(pler.



!A"E "&U*

Nanoltration Membranes for

Removal of !olour an' atho%ensin "mall ublic rinin% 0ater

"ources/

ll bli li !



%(all public +ater supplies t!at use

sur"ace +ater as source "or drin7ing

+ater are "re9uently "aced +it! elevatedlevels o" colour and #'M +!ic! are

precursors "or c!lorinated / "or(ation.

#F syste(s can prevent / "or(ation

by re(oving colour and #'M be"ore

c!lorination.&esearc! studies +ere conducted in Fall

a7e +ater in Minnesota and

dec!lorinated otable +ater s i7ed +it!



Fyne processeveloped in %cotland in 144D to treat!ig!ly coloured sur"ace +aters.&e9uires no pretreat(ent o" "eed +aterot!er t!an a coarse screen to prevent t!eentry o" large solids.

C!osen because o" its (ini(alpretreat(ent and c!e(ical cleaningre9uire(ents and its uni9ue (ec!anicalcleaning "eature. 6!e process uses a tubular se(iper(eable (e(brane to allo+ cleanfltered +ater to pass t!roug! +!ileretaining (icrobial conta(inants and (ost

o" t!e colour producing organic (aterials



%ur"ace +ater treatability studies +ere conductedin Fall la7e +ater, Minnesota, "or re(oval o"

(icroorganis(s and organic (atter in 2008 and2004.)dditional studies +ere conducted +it! t!e sa(eFyne process pilot unit using dec!lorinated potable+ater spi7ed +it! #'M in '!io./ilot unit +as ftted +it! t+o 3 "t vertical(e(brane (odules (ade o" acrylonitrilebutadiene styrene plastic.Iac! (odule contained 52 individual 0.41(

tubes./C type I%D0D polyet!ersul"one (e(brane +it!a D,000 alton MC', /C type C)2/F celluloseacetate (e(brane +it! a 2,000 alton MC' andin 2004, t!e I%D0D (e(brane +as tested again inMinnesota, along +it! a /C type )FC30 polya(ide





N# membrane 1u2 results fromMinnesota 345567



Results E"858 !A4#

#lu2 rates 948+:m4:'ay 956+:m4:'ay

Apparentcolourremoval

;;< ;=<

Removal of

particles>4?m

4.=lo% 4.8lo%

)ron an'Man%anese

!ompleteremoval

!ompleteremoval

!alcium 4=< 4=<

Ma%nesium @< @<Flu declined by 18> J 5> respectively "or t!e t+o

(e(branes.



N# membrane 1u2 results fromMinnesota3455;7



Results E"858 A#!5

#lu2 rates 948+:m4:'ay 855+:m4:'ay

!olourremovaleciency

;5.C< ;.<

Removal of

particles>4?m

4.4lo% 4.lo%

)ron an'Man%anese

!ompleteremoval

!ompleteremoval

!alcium 84< 9<

Ma%nesium 4;< @55<ot! ;u rates are greater t!an design ;u rates.



/ studies in Minnesota.

n 2008, t!e I%D0D and C)2/F

(e(branes re(oved 42 and 53> o" 6'C

respectively.

I%D0D and C)2/F reductions o"

ultraviolet U 2$D +ere 4K and K4>,

respectively.

n 2004, t!e I%D0D (e(brane re(oved

only 5K> o" 6'C, +!ereas t!e )FC30



/article count results "ro( Minnesota 2008



)bove table represents t!e 2 J 3L(

particle re(oval results, sa(e siAe range o"

Cryptosporidium.

n;uent +ater-average particle count o"

3DD0(l.

Iuent +ater, "or I%D0D-average particle

count-1D(l.

Iuent +ater, "or C)2/F- I%D0D-average

particle count-15(l.

6!us,44.K and 44.$> re(oval, respectively



Colour re(oval results "ro( Minnesota.



6'C and colour re(oval results "ro( '!io 2004



!ON!+U")ON"/n Minnesota, t!e I%D0D (e(brane

s!o+ed noticeably better per"or(ance incolour re(oval t!an t!e C)2/F(e(brane. 6!e I%D0D and C)2/F (e(branes bot!s!o+ed 44.$> re(oval eGciency "orparticles in t!e 2 and 3 N( siAe rangest!e siAe range "or Cryptosporidiu(.

6!e colour re(ovals ac!ieved by t!eI%D0D and )FC30 (e(branes in treatingFall a7e +ater +ere also satis"actory.n '!io, t!e Fyne process (e(branes

de(onstrated good colour and 6'C



6!e results o" t!is study indicate t!at t!e Fyneprocess nanofltration syste( could be usedat very s(all serving 2$O$00 people public

+ater syste(s to reduce colour and (icrobialpat!ogens in drin7ing +ater. 6!e 6'C re(ovale!ibited by t!e nanofltration (e(branes+ould also reduce t!e "or(ation o" /s a"terc!lorination.

6!us, t is evident t!at nanofltration +illplay a vital role in providing a 9uality,usable "or( o" +ater in t!e "uture.



&(AND *OU

Nanofiltration in Water Supply Systems

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