DynaSand Oxy DynaSand Deni - aguaslatinas.com

DynaSand Oxy – DynaSand Deni

Nitrogen reduction of municipal

waste water

2015-03-19 2

Nitrogen reduction

• Why is nitrogen treated in municipal waste water?

• In which forms are nitrogen present in municipal waste water?

• How to reduce nitrogen in municipal waste water? • -Nitrification in municipal waste water

• - Denitrification in municipal waste water

• The operation principle of DynaSand for Nitrification & Denitrification of Municipal WWT

• Examples & experiences from municipal using DynaSand Oxy & DynaSand Deni for WWT

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Why is nitrogen treated in municipal waste water?

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•Nitrogen is a elementary nutrient • Often a limiting factor in marine environment

Thereof the necessity to limit the effluent of Nitrogen from industrial & municipal waste water

Large biological production (Algea blooms )

Large decomposion (O2-shortage)

Oxygen free coastal zone (H2S-formation)

Acc. to Nitrogen cycle

Nitrogen cycle

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Reduction

Nitrogen gas

Plant protein

Animal protein

Ammonia -N

Nitrite-/Nitrate -N

Nitrogen forms in municipal waste water

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Ammonia (Ammoniac) -N Org. bound -N Nitrate -N Nitrite -N

N-tot

Inorganic substances could be reduced by biological processes

Organic substances could be reduced as filtration of particles.

Nitrification

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Ammonia -N Nitrate -N Nitrite -N

Nitroso- bacterias:

Is done in two steps of two types of bacteria groups:

2NH4+ + 3O2 +

2NO2-

4H+ 2H2O

+ 3O2 2NO3- + 2H2O Nitro- bacterias:

NH4+

+ 2NO2-

NO2- NO3-

4,3 gram O2 is consumed when 1 grams of NH4+ is oxidized to 1 gram NO3-

Nitrification speed / reactivity

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Expressed as: Kg converted NH4+ / m3 filter media, day

In municipal waste waters are the reactivity NH4+ in the range of: 0,3 -1,2 kg/m3, day

Reactivity = f [ Systemparameters , Equipment parameters]

In municipal waste waters are the reactivity BOD in the range of: 1 - 2 kg/m3, day

Reactivity

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Reactivity = f [ Systemparameters , Equipmentparameters ]

Systemparameters:

•Inlet flow (m3/h) •Inlet concentrations (mg/l) •Outlet concentrations (mg/l) •Temperature ( *C ) •pH

•Type of processequipment (DynaSand) • Surface loading rate (m/tim) •Bed depth, (volume) •Type of media •Adjustments as: -Air (Oxygen) -Sand sinking speed -etc

Equipmentparameters:

Correlation between the system- & equipment

parameters and the reactivity

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Surface loading rate (m/tim)

• Higher surface loading rate give a higher reactivity



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•Higher temperature give a higher reactivity

0

0,5

1

1,5

2

2,5

0 5 10 15 20 25

Re

acti

vit

y (

NH

4/m

3,d

ay)

Temperature (*C)

Reactivity vs Temp.



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•Normally gives a higher pH a higher reactivity

0

10

20

30

40

50

60

70

80

90

100

6 6,5 7 7,5 8 8,5 9 9,5 10

% o

f m

ax

. re

acti

vit

y

pH

Reactivity vs PH



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Inlet concentrations of: BOD BOD / (COD) degraded of hetrotrophic bacterias which: •Consume O2 •Require filter media

Until BOD is < 15-20 mg/l

NH4+ High conc. of NH4+ gives a higher reactivity

O2 Oxygen koncentration in the water should be kept > 3mg/l

HCO3- Alcalinity decreases within the process

pH- decrease

PO4- -P Halten bör överstiga > 0,3mg/l



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The outlet concentrations are a design parameter for the selection of the equipment parameters:

•Type of process equipment (DynaSand) • Surface loading rate (m/h) •Bed depth (volume) •Type of media •Adjustments -Air (Oxygen) -Sand sinking speed -etc

Denitrification

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Nitrate -N

Denitrification bacterias prefer using O2 as energy instaed of NO3- : -that´s why the O2 concentration have to be very low

NO3- + Org. Subs. H+ HCO3- + N2

NO3-

+

N2

Nitrogen gas

Denitrification speed / reactivity

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Expressed as: Kg converted NO3- / m3 filter media, day

In municipal waste waters are the reactivity in NO3- the range of: 0,5 -2 kg/m3, day


Reactivity

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Systemparameters:

•Inlet flow (m3/h) •Inlet concentrations (mg/l) •Outlet concentrations (mg/l) •Temperature ( *C ) •pH •Type of carbon source

•Type of process equipment (DynaSand) •Surface loading rate (m/h) •Bed depth, (volume) •Type of media •Adjustments -Sand sinking speed. -etc

Equipment parameters:



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Inlet flow (m3/h) Surface loading rate (m/h)

• Higher surface loading rate gives a higher reactivity •But the outlet SS is often a limiting factor •Often relatively low surface loading rate (8-12 m/h)



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•Normally a higher pH gives a higher reactivity also for denitrification

0

10

20

30

40

50

60

70

80

90

100

6 6,5 7 7,5 8 8,5 9 9,5 10

% o

f m

ax

. re

activit

y

pH

Reactivity vs PH



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NO3- High concentrations of NO3- give a higher reactivity

O2 Oxygen concentrations should be kept < 3mg/l

HCO3- Alcalinity will increase within the process

pH-increase

PO4- -P

Inlet concentrations of:



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Inlet concentrations of:

Org. Material BOD

Natural Organic Material (NOM) in the inlet water could be used: •Which lead to a saving in the external carbon source

External carbon source

External carbon source in addition to NOM increase the reactivity Common external carbon sources are: Metanol, Etanol etc -The reactivity between them varies

O2

HCO3-

•But they cost quite a bit! •Could lead to higher COD in outlet

To reduce 1 gram of NO3- approx , 3 gram of carbon source is required For every mg/l O2 in the inlet 1,2 mg/l extra carbon source is required



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The outlet concentrations are a design parameter for the selection of the equipment parameters:

•Type of process equipment (DynaSand) •Surface loading rate (m/h) •Bed depth, (volume) •Type of media •Adjustments -Sand sinking speed. -Oxygen in inlet, etc •Carbon souce

DynaSand-filter history

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The first DynaSand filter is tested at municipal waste water in august 1978:

The first DynaSand filter is installed at surface treatment industry in 1979:

The first intensive pilot tests with nitrogen reduction were performed at Louddens WWTP in Sweden 1985:

Flow of water and sand

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DynaSand vs DynaSand Oxy and

Deni

2015-03-19 25 DynaSand DynaSand Oxy & Deni

Filter bed height is higher

Filter material –Basalt/Sand

Where on a WWTP should DynaSand Oxy

och Deni be installed?

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Thickening

DynaSand Oxy & Deni

Primär-

Sedimentering

Biologi

Fine screen & Sandtrap

Final- sedimentation

Sludge dewatering

DynaSand Oxy – for nitrification &

BOD-reduction

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Air Supply:

Air lift pump

1,6-5 bar

On/Off regulation

Process air

1-2 bar

On, On/Off regulation


BOD-reduction

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Filtration zon

Nitrificationszon

DynaSand Oxy – för nitrification &

BOD-reduction

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BOD-reduction

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Typical values -Nitrification

DynaSand Deni – denitrification &

koagulation for phosphorus

reduction

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Pre- denitrification

Fe

BOD-reduc. Nitrification

sed. O2 -Shortage O2 Prim. Sed.

FeCl

Carbon source

Final- denitrification

DynaSand Deni

Control of dosage of external

carbon source

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Denitrification & Phosphorous

reduction

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mg/l

8/8 13/8 15/8 20/8 22/8 5/9 11/9

12/8 14/8 19/8 21/8 4/9 10/9 12/9

25

20

15

10

5

0

Surf. m/h

NO3ŠN in

25

20

15

10

5

0

Surface load m/h

Pof out

NO3ŠN out

Denitrification & phosphorus

reduction

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Case Story - Gillingham

• Designflow 76 l/s (273 m3/h), Average flow: 32 l/s (115 m3/h)

• Inlet conc: 25:30:17 95%ile (BOD:TSS:Amm)

• Outlet demand: 15:30:8 95%ile (BOD:TSS:Amm)

• Should be able to treat average flow when one filter is out of operation

• Should be able to meet outlet demand down to 5ºC

• Nordic water design: – 4 st DS5000 Oxy 5.0

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Case Story - Gillingham

Preformance test should be made and following tests were preformed:

• 10 day preformence test during Qdim

• Ammonia peak at max.flow (FFT)

• Ammonia peak at min. flow (DWF)

• Hydaulic test at max. flow with one filter out of operation

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Gillingham Performance Tests

BOD 24 hr Composite Results

0

10

20

30

40

50

60

70

11-May-05 12-May-05 13-May-05 14-May-05 15-May-05 16-May-05 17-May-05 18-May-05 19-May-05 20-May-05

Date

BO

D m

g/l

0

20

40

60

80

100

120

140

160

180

200

BO

D L

oad

kg

/d

Feed BOD Effluent BOD BOD Consent Limit BOD 95%ile Design Load BOD Load

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Suspended Solids 24 hr Composite Results

0

5

10

15

20

25

30

35

40


Date

SS

mg

/l

0

20

40

60

80

100

120

140

SS

Lo

ad

kg

/d

Feed SS Effluent SS SS Consent Limit SS 95%ile Design Load SS Load

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Ammonia 24 hr Composite Results

0

5

10

15

20

25


Date

Am

mo

nia

mg

/l

0

10

20

30

40

50

60

70

Am

mo

nia

Lo

ad

kg

/d

Feed Amm Effluent Amm Amm Consent Limit Amm 95%ile Design Load Amm Load

10 day performance test

Result – average values

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BOD mg/l

SS mg/l

NH4+ mg/l

Design 95%ile

25

30

17

Inlet average:

26.6

29.5

17.2

Outlet average:

7.5

9.5

1.69

Outlet demand:

15

30

8

Daily variations NH4+

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Gillingham Diurnal Ammonia Performance

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

13:00

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

00:00

01:00

02:00

03:00

04:00

05:00

06:00

07:00

08:00

09:00

10:00

11:00

12:00

13:00

14:00

15:00

16:00

17:00

18:00

19:00

20:00

21:00

22:00

23:00

00:00

01:00

02:00

03:00

04:00

05:00

06:00

07:00

08:00

10:00

11:00

12:00

13:00

14:00

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19:00

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21:00

22:00

23:00

00:00

01:00

02:00

03:00

04:00

05:00

06:00

07:00

08:00

Time (17th - 20th May 2005)

Am

mo

nia

mg

/l

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

Am

mo

nia

Lo

ad

kg

/hr

Feed Amm Eff Amm Consent Limit Hourly Amm Load Max Design Hourly Amm Load

NH4+ peak

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NH4+ peak at max. flow

0

1

2

3

4

5

6

7

8

9

10

10:45 11:15 11:40 12:00 12:15

Time

Am

mo

nia

Co

nce

ntr

atio

n m

g/l

0

10

20

30

40

50

60

70

80

90

13:20 13:45 14:05 14:15 14:25 14:40

Am

mo

nia

Co

nc

en

tra

tio

n m

g/l

Time

NH4+ peak at min. flow

Ammonia in Ammonia out

Razeburg, Germany

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93m3/h

277m3/h 250m3/h 262 m3/h

27m3/tim

•In operation since Dec -96 •Nitrification 3xDS5000Oxy 5.0 •Denitrification 4 x DS 5000 Deni 3.0 •Qmax : 250 m3/h •Qmedel : 200 m3/h

Ratzeburg, Germany

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Nitrification

Filterarea 15 m2

Filterbäd height 5 m

Bedmaterial

Basalt 1,4 - 2,5 mm

Sand sinking speed 8 mm/min

Wash water amount 15 m3/h

Air requirment 200 Nm3/h

O2 - control 4 mg/l

Denitrification (by-pass)

Filterarea 20 m2

Filterbäd height 3 m

Bedmaterial

Basalt 1,0 - 1,6 mm

Sand sinking speed 8 mm/min

Wash water amount 12 m3/h

Sandwasher type DST 30

External carbon source

Methanol

Nitrate control

Ratzeburg, Germany

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DynaSand Oxy DynaSand Deni LT

Q

Tele Communication

Air O2

NH4

Met

ano

l

P

NO3

Q Filtrate

Outlet

By-pass

Wash water

Sludge

Sedimentation Nitrification Denitrification

Inlet from trickling filters

Ratzeburg, Germany

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Design: In operation:

– SS 100 mg/l 150 mg/l

– COD 100 mg/l 150 mg/l

– BOB5 50 mg/l 50 mg/l

– NH4-N 12 mg/l 20 mg/l

– NO3-N 28 mg/l 37 mg/l

– NTOT 41 mg/l

– PTOT 1 mg/l

Inlet values: Outlet values: Design: In operation:

– SS 20 mg/l 15 mg/l

– COD 80 mg/l 80 mg/l

– BOB5 16 mg/l 16 mg/l

– NH4-N 5 mg/l 2 mg/l

– NO3-N 15 mg/l 10 mg/l

– NTOT 20 mg/l

– PTOT 1 mg/l

Ratzeburg, Germany

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0

5

10

15

20

25

30

35

0

50

100

150

200

250

29.10.199800:31:00

29.10.199803:01:00

29.10.199805:31:00

29.10.199808:01:00

29.10.199810:31:00

29.10.199813:03:00

29.10.199815:33:00

29.10.199818:03:00

29.10.199820:33:00

29.10.199823:03:00

Concentration [mg/l]

Inlet [m3/h]

Date

KA RatzeburgHydrograph DynaSand-Filter

Feed Nitrification

Feed Denitrification

NO3-N out NH4-N out

NO3-N in 28 mg/l NH4-N in 10 mg/l

Temp. 12,7 C

Thanks!

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Nordic Water Products AB www.nordicwater.com

DynaSand Oxy DynaSand Deni - aguaslatinas.com

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