1 Effectiveness of Pollutants Removal

8/11/2019 1 Effectiveness of Pollutants Removal

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University of Warmia and Mazury in Olsztyn

FACULTY OF ENVIONMENTAL !OTECTION AN" FI#$EIE#

La%&e'ort(

"etermination of t)e effe*tiveness of +aste+ater treatment %y

a*tivated slud,e

and

Fluores*ent in situ )y%ridization -FI#$.

/rou' 0( Treated +aste+ater sam'le ta1en at 2345647522

Made by:

To%ias 8os*)

#as*)a $eilemann

e%e**a 9u)n

Lecturer:

!)" 9atarzyna 8ernat

"r4 Ma,dalena :ielins1a

Date: 28.05.2011


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2Determination of the effectiveness of wastewater treatment by activated sludge

Contents

1. im and sco!e of study..........................................................................................................."

2. #esults.....................................................................................................................................5

". Discussion.............................................................................................................................12

nalytical Methods in $iological %ystems


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"Determination of the effectiveness of wastewater treatment by activated sludge

24 Aim and s*o'e of study

&he aim of this laboratory was to determine the effectiveness of !ollutants removal by

activated sludge in de!endence on '(D)* ratio in wastewater. ctivated sludge is a !rocess

used to treat sewage and industrial wastewaters by using an aeration tan+. ,n this e-!eriment

two laboratory singlestage aeration tan+s with activated sludge were used. &he tan+s had the

same volume/ the same !um! with same flow rate and the same dissolved o-ygen

concentration. &here were two different variants used. ariant 1 had a low '(D)&* ratio

and variant 2 had a high '(D)&* ratio. &he '(D)&* ratio s!ecifies the effect of nitrite

and nitrate as inhibitors. &he scheme of this e-!eriment can be seen in igure 1.

Fi,ure 2( #*)eme of t)e e;'eriment4 )? V( rea*tor volume dm=? Ci( 'ollutants

*on*entration influent m, O7>dm=? Ce( 'ollutants *on*entration effluent m, O7>dm=? @( mass of a*tivated

slud,e m,T#>dm=? W( ra+ +aste+ater? TW( treated +aste+ater

or activated sludge/ the following !arameters were determined:

flow rate for the aeration tan+s

reactor volume

mass of activated sludge in aeration tan+s

%, 3 sludge volume inde-



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ll of the ne-t !arameters were determined for both variants of treated wastewater:

!

'(D

&*

**4

**(2

**("

or raw wastewater only the !/ '(D/ &*/ and **4 from the second variant was

measured.

(n another laboratory day/ a fluorescent in situ hybridi6ation was !erformed/ to get the

!ercentage of ammonium o-idi6ing bacteria 7($ in the activated sludge tan+s. &he tan+s

were the same as in the e-!eriment before and visuali6ed in igure 1.irst sam!les from the

two tan+s are ta+en and fi-ed. fterwards they were hybridi6ed and then evaluated via

microsco!e and image analysis.



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74 esults

"etermination of t)e effe*tiveness of +aste+ater treatment %y a*tivated slud,e

,n &able 1are the measured values of the laboratory determinations. &he ! was measured

with a standard !meter. '(D was determined with dichromate method. $(D was

calculated with the '(D. ,n raw water it is assumed that the $(D is 90 of the '(D/ in

treated water 25 of '(D were assumed. &he &* sam!les were minerali6ed and

determined with the distillation)titration method. mmonium in raw water was measured via

distillation)titration method and in treated water via the nessleri6ation. *itrite and *itrate

were determined with the standard s!ectro!hotometric methods/ with a wavelength of 410 nm

for *itrate and 520 nm for *itrite. &he values with grey colour are the mean values for all

grou!s. &hey were used because too high values were determined with our measurement.

Ta%le 2( "etermined values of t)e +aste+ater sam'les? ,rey values are mean values from all ,rou's

a+ Treated

"etermination Unit V2 V7 V2 V7

'$ ! 8/4 8/9 8/"

CO" mg (2)dm" 548 519/0 124/0 152/0

8O" mg (2)dm" "28/8 "0;/9 "1/0 "8/0

T9N mg &*)dm" 58/25 199/9 0/0

Ammonia mg **4)dm" 4uations to calculate the values from&able 1:

l)mg7

1000?8?n?b.a7@'(D'r 'hemical o-ygen demand 7dichromate method

a: volume of MohrAs salt used for blan+ 7ml

b: volume of MohrAs salt used for sam!le 7ml

: volume of sam!le 7ml

8: factor converting obtained result to mg of (2

n: normality of MohrAs salt 70/05 *



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l)mg7

1000?b.a7?14/0@&* &otal Beldahl nitrogen

0/14: milligrams of nitrogen corres!onding to 1 ml 0/01 * 'l

a: volume of 0/01 * 'l in =rlenmeyer flas+ 7ml

b: volume of 0/01 * *a( used during sam!le titration 7ml

: sam!le volume 7ml

l)mg7

1000?a?=@mmonia mmonia 7nessleri6ation method

a: coefficient from standardi6ation curve 70/25


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@F

i

E

&he effectiveness of organics removal is calculated with 100?'

'.'@

i

ei

&he hydraulic loading rate can be determined by

?>@5L#

24

=ffectiveness of nitrification: 100?'.'

'@*%yn&*/i

*(-

ionnitrificat

=ffectiveness of denitrification: 100?'

'@

*(-

*red

ationdenitrific

ll symbols used in the formulas can be found in the table below or are already described

before.



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;Determination of the effectiveness of wastewater treatment by activated sludge

Ta%le ( Cal*ulations of t)e effe*tivenessBs

"etermination Unit V2 V7

CO">T9N ;/41 "/10

Flo+ rate > dm")h 0/18 0/18

ea*tor volume dm" 9/"4 9/"4etention Time t# h "5/22 "5/22

Or,ani* load CO" F'(D +g '(D)m"d 15/59 14/95

#lud,e loadin, rate FE/'(D +g '(D)+g &% d 5/"0 5/25

Or,ani* load 8O" F$(D +g $(D)m" d ;/"4 8/


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Fluores*ent in situ )y%ridization

or the determination of the !ercentage of ($s in the sam!les/ 14 sam!les were e-amined

via the ,mage analysis. &he !rinci!le of this analysis is to measure the biovolume fraction of

the ($s relative to the total microbial community. &he ($ area fraction is then measured

as !ercentage of total area of all organisms. &he result of this analysis is shown in &able 5.

Ta%le 6( "etermined values and mean values of t)e determination of AO8s in t)e sam'les

Determined !ercentage of ($s in the

sam!le 7

#eactor 1 #eactor 2

11/99 11/849/


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3,1 9,41

0

5

10

15

20

25

30

35

0

10

20

30

40

50

60

70

80

90

100

*itrification =fficiency and ($7: versus '(D)*

'(D)* ratio

($7:8

*itrificationefficiency7:

8

Fi,ure ( Im'a*t of CO">N ratio to 'er*enta,e of AO8 'resent and effi*ien*y of nitrifi*ation

Hictures of the total microbial community and the ($s !resent can be seen in igure 4and

igure 5.&he !ictures are showing the sam!les under the e!ifluorescence microsco!e.

Fi,ure ( !i*ture of total mi*ro%ial *ommunity

'resent in a*tivated slud,e sam'le under

e'ifluores*en*e mi*ros*o'e

Fi,ure 6( !i*ture of AO8s -dar1 red. 'resent in

a*tivated slud,e sam'le under e'ifluores*en*e

mi*ros*o'e


($


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4 "is*ussion

&he two reactors are different in the '(D)&* ratio. ,n reactor 1 the ratio '(D)&* is with

a value of ;/4mg)l com!ared with "/1 mg)l about "times higher. &he big difference is caused

by the &* value which is in variant 1 with a value of 58/25 mg)l and in variant 2 with an

value of 199/9 mg)l around three times smaller. &he organic load '(D/ the sludge loading

rate and the organic load $(D are almost e>ual in both reactors.

&he &% value of variant 1 was 2;"4 mg)l. &he &% value of variant 2 was 2


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1"Determination of the effectiveness of wastewater treatment by activated sludge

&he nitrifying bacteria in the activated sludge grow in the form of micro colonies embedded

in floc+ of heterotro!hic microorganisms/ ma+ing the heterogeneity of the microsco!ic

images high. &herefore/ the main advantage of the ,% measured by fluorescent

s!ectrometry is that the data are obtained for the bul+ of the sam!le and do not de!end on the

!resence of aggregates or !articles in the sam!le I"J.

,n our case reactor 1/ with the higher '(D)&* ratio/ has the lower amount of ($s because

of the higher amount of &* in reactor 2.

&he !rocess denitrification with an effectiveness of 41 7#1 and 80 7#2 shows a

de!endenc which is caused on the fact that maybe in #2 there was more nitrate. *itrate is

converted into nitrogen gas in the denitrification ste! under ano-ic conditions.

,n our case the efficiency of denitrification is higher with an low '(D)&* ration in variant

2. &his is unusual/ because normally increasing the ')* ratio increased the nitrate removal

rates 7nitrification I4J.

&he effectiveness of denitrification is low in both reactors and would need further ste!s of

denitrification/ usually in an anaerobic stage. ,n our case there were aerobic conditions in

both reactors. &he usual denitrification needs anaerobic conditions. $ut there are some

bacteria which have the !ossibility for denitrification under aerobic coditions. im et al. have

analy6ed the aerobic denitrification of Hseudomonas !utida D21 at different ')* ratios. &he

o!timal ')* ratio was 8 with a ma-imum nitrate removal rate of 254.9mg)l)h and a nitrate

removal efficiency of ;5.;. &heir results suggest that H. !utida D21 may be a good

candidate for aerobic wastewater treatment I4J.


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1 Effectiveness of Pollutants Removal

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