Extended Aeration Sbr

7/17/2019 Extended Aeration Sbr

http://slidepdf.com/reader/full/extended-aeration-sbr 1/32

Site visit

8.00 am – 1.00 pm,29/4/13

Group assignment

• Prepare a report about yourvisit to the treatment pants.



Before your visit

! goo" i"ea is to "o some preiminaryresear#h on the operations o$ the pant /#ompany.

1. %se the internet, #ompany reports, an"boo&s to investigate some o$ theprimary pro#esses.

2. 'hin& about (hat you area"y &no(about the #ompany, ist as mu#hin$ormation an" (or& $rom there.



During your visit

)uring your visit try to be a#tiveyengage" in (hat you are e*perien#ing

TIPS:

1. Ask questions when you have theopportunity. Sta involve in presentingthe operations of the !o"pany are likelyto e#pe!t questions$ an are usually"ore than happy to a!!o""oate.

%. Prepare so"e questions &efore you visit$&ut then "oify the" where possi&le.

'. (se question asking perios to ask anyquestions that "ight help with the

writing up of your assign"ent.



During your visit

! $urther goo" habit to get in to is ta&ingnotes "uring your visit. %se any pra#ti#aopportunity to re#or" any impressions /observations you have o$ a aspe#ts o$ the

visit.Site )isit *eport +he!klist+a&e sure be$ore your site visit you have

-ea" up on the site you are visiting he#&e" the (ebsite o$ the #ompany $or reevant

in$ormation Prepare" a ist o$ uestions to as& sta -ea" any assessment in$ormation - you visit the

5e" Prepare" a noteboo& $or ma&ing notes as you go (ith

hea"ings prepare".



,any site visit reports ten toin!lue so"e or all of the followingse!tions: an e#e!utive su""ary$ an

introu!tion$ a &rief overview of thelo!ation$ aes!ription of pro!esses at the plant$a se!tion where o&servations an

re-e!tions on the plant areis!usse$ an so"eti"esre!o""enations.

6riting up your site visit report



7*ten"e" aerationa#tivate" su"ge



!#tivate" su"ge – an overvie(

Primary

treatment

Secondary

treatment



!#tivate" su"ge pro#ess variations

• Step aeration

•

'apere" aeration• *i"ation"it#h

• *ten"e" aeration :!;

• Seuen#ing at#h -ea#tor :S-;



• !erobi# pro#ess• %se" e*tensivey $or prefa&ri!ate

pa!kage treat"ent plants to treat

(aste(ater in sma #ommunities, oron in"ivi"ua properties. aerationbasin may be #astinpa#e #on#rete

or stee tan& $abri#ate" in $a#tory.• <an"ing o( voume o$ (aste.

*ten"e" aeration



• +e#hani#a simpi#ity 'he ra(se(age goes straight to the aerationtan& $or treatment.

• 7*ten"e" aeration 'he mi*ture isaerate" onger than usua. 'hisao(s organisms to &eep gro(ing

an" $ee"ing, brea&ing "o(n thesu"ge.



S!he"ati! low +hart of an /#tene Aeration Syste"

Aerationtank

FinalClarifer

I0(/0T2 *A3

S/3A4/

T*/AT/D/(/0

T

3AST/D

S(D4/

S(D4/*/T(*0



,ass Balan!e•

'he mass baan#e #on#ept is base" on the$un"amenta physi#a prin#ipe that matter#an neither be #reate" nor "estroye".

• ! baan#e on a #ontinuous pro#esses at

stea"y state may be (ritten as

=nput > Generation ? utput > onsumption



+ass baan#e $or biomass


iomass =n > iomass Gro(th ? iomass ut

Bio"ass In 5 Bio"ass 4rowth 6 Bio"ass /7uent 5 Bio"ass 3aste sluge

I0(/0T2 *A3

S/3A4/

T*/AT/D/(/0

T

3AST/DS(D4/

S(D4/*/T(*0

Aerationtank

FinalClarifer

@o

, So

, Ao

∀, S, A@o > @r

A, S @o – @(

Ae, S

@u, Au@r, Au

@(, Au



Eq. 7.1

Bio"ass

4rowth

Bio"ass/7uent

Bio"ass3astesluge

6hereB@o,@( ? =nCuent an" (astesu"ge Co( rate,m3/"Ao, A, Ae, Au ? biomass #on#entrations in inCuent,rea#tor, eDuent an" #ari5er

un"erCo(:(aste su"ge;, respe#tivey,&g/m3

So, S ? soube $oo" #on#entration in theinCuent an" rea#tor, respe#tivey, &g/m3

∀ ? voume o$ rea#tor, m3

E s ? ha$ saturation #onstant,&g/m3

&o ? ma*imum gro(th rate #onstant, "

1

&" ? en"ogenous "e#ay rate #onstant, "1

+ass baan#e $or biomass

Bio"ass In

uwewod

s

ooo X Q X )QQ( ) X k

S K

XS k ( X Q +−=−

+∀+



+ass baan#e $or substrate :$oo";


oo" =n oo" onsume" ? oo" ut

oo In 8 oo +onsu"e 6 oo /7uent 5 oo 3aste Sluge

I0(/0T2 *A3

S/3A4/

T*/AT/D/(/0

T

3AST/DS(D4/

S(D4/*/T(*0

Aerationtank

FinalClarifer

@o

, So

, Ao

∀, S, A@o > @r

A, S @o – @(

Ae, S

@u, Au@r, Au

@(, Au



+ass baan#e $or substrate :$oo";

Eq.7.2

ooIn

oo+onsu"e

oo/7uent

oo3astesluge

6hereB F ? "e#ima $ra#tion o$ $oo" mass #onverte" to biomass

? :mg/ biomass/mg/ $oo" utiiHe";

!ssumptions• 'he inCuent an" eDuent biomass #on#entrations are

negigibe #ompare" to biomass at other points in thesystem

• 'he inCuent $oo" #on#entration So is imme"iatey"iute" to the rea#tor #on#entration S be#ause o$ the#ompetemi* regime

•! rea#tions o##ur in the rea#tor. 'here$ore, thevoume, ∀ represents the voume o$ the rea#tor ony

S QS QQS K Y

SX k S Q

wwo

s

o

oo

+−=

+

∀− )()(



F/M Ratio 0.05 – 0.15 kg

BOD/kgMLSS.day

HRT 18 – 24 o!"#SRT 20 – $0 day#

%o&!'(t"i) Loadi*g 0.1+ – 0.40 kgBOD/'$

MLSS )o*)(*t"atio* $000 – +000 'g/L

R()y)&( Ratio 0.75 – 1.50 ,i" #!--&y 0 – 125 '$/kgBOD

"('o(d

Design an 9perational

Para"eters



*ampe

An Extended Aeration STP treats 1500 m3 osewage daily wit a !"# concentration o300 mg$%& Calc'late te (ol'me re)'ired orte aeration com*artment& +ence, ceck te

+ydra'lic -etention Time .+-T/ and te (ol'metric loading& #etermine te )'antityo sl'dge wasted *er day& Ass'me a %SSconcentration o 3500 mg$% and a Solids-etention Time .S-T/ o 5 days&



Pro!ess -ow !hart

Aerationtank

FinalClarifer

o 1500 m3$d

So 0&3 kg

!"#$m3

4 .%SS/ 3&5kg$m3tc .S-T/ 5

d?

2w4'?

+-T?

?

∀

L∀



So&!tio*

1. Fi*d o&!'(

Coose F$ ratio as

0&1 kg !"#$kg %SS&day

X

QS

M

F o

∀=

5.3

3.015001.0

×∀

×=

31286m=∀∴



= 20.6 hoursOK (18 < HRT < 24)

2. Fi*d HRT

2415001286 HRT ×=

oQ )t ( HRT ∀=



$. Fi*d o&!'(t"i) &oadi*g

= 0.35 kgBOD/m3

(OK : 0.16 < < 0.40)

∀=∀ oo

L S Q

1286

3.01500×=

L∀



4. Fi*d q!a*tity o #&!dg( a#t(d

∴ u!"#$#% o& s'ug *!s#+ Qw X u =

= 180 kg/!%

uw X Q

X SRT

∀

=

25

5.31286×



@uiH

1. )e5ne se#on"ary treatment

2. )e5ne a#tivate" su"ge pro#ess

3. )es#ribe the environmenta $a#tors that inCuen#e theheath an" gro(th o$ mi#roorganisms.

4. *pain ho( soi"s are generate" in an aeration basin, an"the #onseuen#es to the operation i$ e*#ess soi"s are notremove" :(aste";.

I. or ee#tive treatment, a #ertain su"ge age is "esire" $orthe type o$ a#tivate" su"ge system. or #onventiona

a#tivate" su"ge, a su"ge age o$ 41I "ays is typi#a. ore*ten"e" aeration a#tivate" su"ge, o"er su"ge ages o$2030 "ays are #ommon. Spe#i$y a reationship bet(eenthe su"ge age an" /+ ratio.



S@%J=JG!'< -!'-S:S-;



•

S- is a 5an""ra( a#tivate" su"ge system.• 6aste(ater is a""e" to a singe bat#h rea#tor

an" then "is#harge". uaiHation, aerationan" #ari5#ation :se"imentation; are a

a#hieve" in a singe bat#h rea#tor using a time#ontro seuen#e.

:=n a #onventiona a#tivate" su"ge system,

these unit pro#esses (ou" be a##ompishe" byusing separate tan&s;.



S- perationphases

ill: 6aste(ater enters the

rea#tor.*ea!t: 6aste(ater isaerate". -ea#tion time"epen"s on the eDuent

uaity reuire".Settle: iomass separation$rom 5na eDuent. -ea#tora#ts i&e a se"imentationtan&.

De!ant: ina eDuent is"ra(n out o$ rea#tor eavingbehin" the sette" su"ge.Ile: 'ime bet(een

"e#anting an" 5. 'ime

)e#ant



• 'o optimiHe the per$orman#e o$ thesystem, t(o or more bat#h rea#tors

are use" in a pre"etermine"seuen#e o$ operations.

For continuous-fow application, one tank receivesfow while the other completes its treatment cycle.



'he #entra $eatures o$ the S- system :the hearto$ the system; in#u"e the #ontro unit an" theautomati# s(it#hes an" vaves that seuen#e an"time o$ the "ierent operations.

S- manu$a#turers shou" be #onsute" $orre#ommen"ations on tan&s an" euipment. =t istypi#a to use a #ompete S- system

re#ommen"e" an" suppie" by a singe S-manu$a#turer.

'he S- system#onsists o$ a tan&,

aeration an" mi*ingeuipment, a"e#anter, an" a#ontro system.



aboratory s#ae S-



!"vantages

• reuire ess spa#e sin#e euaiHation,bioogi#a treatment an"se"imentation #an be a#hieve" in a

singe rea#tor

• operating Ce*ibiity an" #ontro

• #apita #ost savings by eiminating

#ari5ers an" other euipment



)isa"vantages

• higher eve o$ maintenan#e

• potentia "is#harging o$ sette"su"ge "uring "e#ant phase

• higher eve o$ sophisti#ation :timingunits an" automate" #ontros;

Date post:	06-Jan-2016
Category:	Documents
Upload:	nabilah
View:	46 times
Download:	8 times

Extended Aeration Sbr

Documents