Oxygen Requirements

8/20/2019 Oxygen Requirements

1/22

Monroe L. Weber-Shirk School of Civil and

Environmental Engineering

Nutrient Removal Project

!"#gen Re$uirement%

&! 'robe

Stir bar (ir )em'erature 'robe

Pre%%ure

%en%or

*i%tor# of *uman Wa%te


&i%%olved o"#genmea%urement%

!"#gen )ran%fer

http://ceeserver.cee.cornell.edu/mw24/Default.htmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/faculty/info.cfm?abbrev=faculty&shorttitle=bio&netid=mw24http://www.cornell.edu/http://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://www.cee.cornell.edu/index.cfmhttp://ceeserver.cee.cornell.edu/mw24/Default.htm


2/22

E"creta &i%'o%al

Land (''lication

When 'o'ulation den%itie% +ere lo+ e"creta di%'o%al+a% an individual 'roblem.

(% citie% gre+ it +a% no longer 'o%%ible for

individual% to 'ractice ,direct land a''lication. efore /011 cit# re%ident% 'laced ,night %oil in

bucket% along %treet% and +orker% em'tied the +a%teinto ,hone#+agon tank%.

)he +a%te +a% tran%'orted to rural area% for di%'o%alon farm land. )he hone#+agon %#%tem 're%erved thee%%ential feature of land a''lication of the +a%te.

Nutrient Rec#cle


3/22

)oilet%

2ntil about /031 even the member% ofCongre%% +ere re$uired to go out%ide and

+alk do+n Ca'itol *ill to 'riv# facilitie%. /031-/411 )he flu%h toilet came into

general u%e in the 2.S. during the la%t halfof the nineteenth centur#.

5ntroduction of the toilet coincided +ith 666666 66666.central heat


4/22

Night Soil v%. Se+er%

&utch engineer Charle% Liernur advocated dr#

di%'o%al. *e claimed underground %e+er% +ould

be the %ource of 66666666 66666 giving ri%e to

%ickne%% and death.

Engli%h engineer ald+in Latham %u''orted +ater

carriage of e"creta. Latham 'roceeded +ith the

in%tallation of a +ater carriage %#%tem forCro#don7 +here he +a% engineer of 'ublic +ork%.

)he +ater carriage %#%tem led to an immediate

decrea%e in the death rate in the citie% that in%talled

it.

no"iou% ga%e%

ut +hat about the citie% do+n%tream8


5/22

Conver%ion of Storm Se+er% to

,Sanitar# Se+er%

)oilet% +ere connected to e"i%ting %torm

%e+er%

)he %torm drain %#%tem% di%charged directl#

to %tream%7 lake%7 and e%tuarie% +ithout

treatment

)reatment of +a%te+ater onl# became an

i%%ue after the %elf-'urification ca'acit# of

the receiving +ater% +a% e"ceeded and

66666666 6666666666 became intolerablenui%ance condition%


6/22

Wa%te+ater into Stream%

Enter Environmental Engineering9

&rinking +ater treatment began to receive attention inthe /011%.

London7 and citie% on the :reat Lake% found

them%elve% draining their ra+ %e+age into the %ame bod# of +ater from +hich the# took their drinking+ater. Chicago %olved thi% 'roblem b# rever%ing the flo+ of the

Chicago river and %ending it% +a%te through a canal to the

5llinoi% River to the Mi%%i%%i''i. Engli%h engineer% tackled the 'roblem b# develo'ing

treatment techni$ue% for both +a%te+ater and drinking +ater.


7/22

Evolution of )reatment :oal%

Solid% ;%edimentation<

!& ;activated %ludge<

Nitrification ;convert ammonia to nitrate<

&enitrification ;convert nitrogen to N=<

Pho%'horu% ;get bacteria to take u' 'ho%'horu% %o 'ho%'horu% can be removed

+ith the %ludge<


8/22


)he challenge build an automated+a%te+ater treatment 'lant that remove%

organic carbon and ;if +e have timeariou% nitrogen removal %trategie%

Maintain high cell concentration% u%ingmembrane filter% or %edimentation

We need to monitor o"#gen level%

We need air o" en ?


9/22

!"#gen Probe

anode cathode = =@ @ =e H O H O- ++ + ®

!"#gen 'ermeable membrane

( 1.0 > >oltage %ourceCurrent meter

ACl electrol#te!Bring

1 nanoam'% t#'icalat DC and /

atmo%'here in air.

!"#gen con%um'tion le%%than /1-D gram% of o"#gen

'er hour ;le%% than 1./ FL of

o"#gen 'er hour< in air.


10/22

&i%%olved !"#gen Probe )heor#

(''lied 1.0 > reduce% != to *=! at the cathode and

kee'% the != concentration ver# lo+

)he cell i% %e'arated from %olution b# a ga% 'ermeable

membrane that allo+% != to 'a%% through )he rate at +hich o"#gen diffu%e% through the ga%

'ermeable membrane i% 'ro'ortional to the difference ino"#gen concentration acro%% the membrane ;'ro'ortional

to the o"#gen concentration in the %olution< !"#gen reduction 'roduce% a current that i% mea%ured b#

the meter

= =@ @ =e H O H O- ++ + ®

m m

C J D

x

D=-

D


11/22

&i%%olved !"#gen Probe

Calibration

Single 'oint ;linear< calibration at %aturation

Saturation concentration)em'erature de'endence

(tmo%'heric 're%%ure de'endence

Membrane tem'erature effect

&iffu%ion through membrane i% a function oftem'erature

Linear calibration coefficient

E$uation for calculating &!

( )1.13; < ref

T T

membranek T e-

=

( )1.13ref T T

kV C

e -=

( )GG

cal membrane cal

cal

C k T k

V =

H

D

0

4

/1

//

/=

/1 =1 1 @1

)em'erature ;C <

' ' m

=

/D=D=./13G

T O

C P eæ ö

-ç ÷è ø=


12/22

What Control% !"#gen )ran%fer8

666666666666666666666

666666666666666666666

666666666666666666666

666666666666666666666

66666666666666666666666666666666666666

666666666666666666666

&eficit

tran%fer coefficient

ubble %urface area

ubble re%idence time

)urbulence

7

I; G


13/22

(eration

5nitial !"#gen &eficit7 No !&

C*

C

t

Do = 5 mg/L

3 mgJL

C* = oxygen concentration in e!i"i#ri!m $it% atmo&'%

Where i% the be%t data for calculating 87I

v l k


14/22

Mea%uring the )ran%fer

Coefficient

S'ecific for a 'articular reactor

de%ignJconfiguration and for a %'ecific flo+

rateWe +ant to kno+ ho+ the tran%fer

coefficient varie% +ith flo+ rate ;%o +e can

e%timate ho+ much o"#gen +e aredelivering<

7I

v l k

G

7 1G

1

Iln ;


15/22

(eration Method%

&iffu%ed (eration S#%tem%

;com're%%ed air 'um'ed into

aeration tank%<Porou% diffu%er%

Ceramic

Pla%tic membrane% Non-'orou% diffu%er% ;hole in a 'i'e<

Mechanical (eration S#%tem%


16/22

!"#gen )ran%fer Efficienc#

;!)E<

Percentage of the ma%% of o"#gentran%ferred into the +ater divided b# the

ma%% of o"#gen %u''lied to the +ater Kou +ill calculate !)E for #our %#%tem

!)E +ill be le%% under +a%te+ater

condition%Lo+er o"#gen %olubilit# ;%alt%7 organic matter<

Lo+er %urface ten%ion

7

I ; G <v l

dC k C C

dt

= -


17/22

!"#gen )ran%fer Efficienc#

!= di%%olved J != delivered

*o+ do +e mea%ure the rate that o"#gen i%

di%%olving8

=

=

o

O

V dC n MW dt

( =

( )G7Iv l dC

k C C

dt

= -

( )=

=

G

7I

o v l

O

V n k C C

MW ( = -

!ur goal i% to mea%ure thi% in lab

ut dC/dt varie% +ith o"#gen deficit

(fter +e have mea%ured the tran%fer

coefficient +e can ea%il# calculate

the o"#gen tran%fer rate

Com'are +ith %u''lied != flo+ rate


18/22

Standard !"#gen )ran%fer

Efficienc# ;S!)E<

Ma%% of o"#gen tran%ferred under %tandard

condition% 'er unit of power in'ut

=1C ero di%%olved o"#gen in the li$uid 'ha%e

Clean +ater

:iven b# manufacturer% of aeration e$ui'ment

:enerall# bet+een /.= =.D kg != 'er kWh

ield !"#gen )ran%fer Efficienc# ;!)E< i%

%ignificantl# lo+er


19/22

(ir Su''l# &e%ign Oue%tion%

*o+ much o"#gen +ill be re$uired b# the+a%te+ater8

*o+ much air +ill need to be %u''lied8 Number of diffu%er%

Reactor configuration ;%hallo+ v%. dee'<

*o+ +ill +e %u''l# the air8Peri%taltic 'um' ;can be com'uter controlled<

Laborator# com're%%ed air ;/11 kPa %ource<


20/22

&iffu%er (ir Su''l# &e%ign

5f +e u%e the laborator# air %u''l# for the NRP ;/11kPa< ho+ could +e regulate air flo+8

We ma# need to u%e the 'eri%taltic 'um' for another 'art of the 'roce%%.

We have com'uter controlled %olenoid valve%.

(n# idea%8

Ea%# %olution%8 :reat %olution%8

What +ould #ou like the ca'abilitie% of thi% device to be8

*o+ could #ou give the device the ca'abilitie% #ou

+ant8

Electromagnet turn% on and off


21/22

Pre'aration for Lab

Read the %ection on Proce%% Control ;Page%/=/-/=3 in the Lab Manual<

Come read# to 'la#(%k lot% of $ue%tion%9

Make it #our goal to under%tand a% much of

the %#%tem a% #ou can9Kou +ill be a%%embling the airflo+ control

hard+are


22/22

Lab Setu'

S1(ir Su''l#

N1 N2

&! 'robe

Stir bar

)em'erature 'robe

=11 kPa

Pre%%ure%en%or

Needle >alve%

Solenoid >alve

(ccumulator

D kPa

Pre%%ure

%en%or

S2

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Oxygen Requirements

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