Putting the Misconceptions to Rest:

2010 HWEA ConferenceHonolulu, HI

Brandy NussbaumI. Kruger, Inc

Clarification/Separation OPTIONS Following MBBR Treatment

Discussion Topics

• What is MBBR• Conventional Clarification• High Rate Ballasted Clarification• Dissolved Air Flotation• Discfiltration• Granular Media Filtration• Membranes• Summary

Aerobic reactor

The Principle of the Moving Bed Biofilm Reactor (MBBR) Technology

Anoxic reactor

The Moving Bed Biofilm Reactor (MBBR) in Practice

Components to the MBBR Aerobic SystemAnoxKaldnes MediaMedia Retention Sieves• 304L Stainless Steel • Cylindrical Wedge Wire• Perforated Plate foam control sievesAnoxKaldnes Aeration Grid• 304L Stainless Steel • Medium Bubble• Maintenance Free – No replacement parts

Components to the Anoxic MBBR System

AnoxKaldnes MediaMedia Retention Sieves• 304L Stainless Steel • Flat Panel Wedge WireSlow-Speed Mixers• Submersible or Top entry• Can be speed controlled

MBBR Solutions – Highly Flexible

MBBR stand-alone

MBBR as pre-treatment (roughing, BASTM)

MBBR as tertiary treatment(polishing, LagoonGuardTM)

MBBR in activated sludge (HYBASTM/IFAS)

MBBR Biomass Separation Alternatives

MBBR –Actiflo™(ballasted flocculation)

MBBR - settling

MBBR - Flotation

MBBR – Media Filtration

MBBR – Disc Filter

MBBR – Membrane Filtration

Development of PSD’s at various MBBR loadings (HRT’s) (Åhl et al, 2006)

0

2

4

6

8

0,01 0,1 1 10 100 1000particle diameter µm

diff

volu

me%

inlet HRT = 1hHRT = 2hHRT = 3hHRT = 4h

0

2

4

6

8

0,01 0,1 1 10 100 1000particle dimeter [µm]

diff

num

ber%

inletHRT = 1hHRT = 2hHRT = 3hHRT = 4h

1. There is a shift towards a higher volume of largerparticles with increasing HRT

2. There is at the same time,however, a relative increasein the number concentrationof submicron particles withincreasing HRT

Hypothesis :• Flocculation is taking place• Erosion of single bacteria or

remains of dead cells happens• Both are f(loading/HRT)

Relative amounts of COD in the different size fractions (Melin at al, 2005)

Majority of COD in particles > 1 µm

Increase in the suspended COD with increasing HRT

Decrease in colloidal particles (0,1 – 1 µm) when HRT increase

0

10

20

30

40

50

60

70

80

>1 µm 0.1-1 µm 30 kD-0.1 µm <30 kD

Size fraction

Amou

nt o

f CO

D (%

)

HRT = 0.75 h HRT = 1 h HRT = 3 h HRT = 4 h

a)

Conventional Settling after MBBR

Withoutcoagulation

CoagulantCoagulantWith coagulation

• Metal salt (Al, Fe)• Cationic polymer• Low Al/Fe + cat. polymer

• High Al/Fe + anionic polymer

Cheyenne – Crow Creek WWTP

THE CROW CREEK WATER RECLAMATION FACILITY THE CROW CREEK WATER RECLAMATION FACILITY

New Treatment ProcessNew Treatment Process

Screening & Degritting

Discharge

PrimaryClarifier

1

PrimaryClarifier

2

SecondaryClarifier

2

SecondaryClarifier

1UV Disinfection

Flow Split Anoxic

Basins(Pre-Denite)

New MBBR Reactors

Future Nitrate Recycle

Reuse Filters

Alum/Polymer Sludge

PERFORMANCE DATA

0.0

5.0

10.0

15.0

20.0

25.0

0.050.0

100.0150.0200.0250.0300.0350.0400.0450.0500.0

Efflu

ent

Influ

ent

Cheyenne BOPU Crow Creek WRFTSS Removal - 30 Day Avgerage

Inf luent Effluent

Actiflo® Microsand Ballasted Clarification

Hydrocyclon

FlocculationInjectionCoagulation

Polymer

Microsand

Coagulant

Inlet

Lamella--sedimentation

OutletMMMM

Sludge

Hydrocyclon

FlocculationInjectionCoagulation

Polymer

Microsand

Coagulant

Inlet

Lamella--sedimentation

OutletMMMM

Sludge

Water

Primary particles

CoagulantMicrosand Polymer

Flocs

Water

Primary particles

CoagulantMicrosandMicrosand Polymer

Flocs

Polymer

Flocs

South Adams WWTP MBBR-ACTIFLO® Pilot

Influent characteristics

Coagulants and dose Effluent characteristics

Process

Rise rate3

mg SS/l Turb FeCl3 or Als(SO4)3 + anionic polymer1

mg SS/l Turb. mg P/l

MBBR +

ACTIFLO®

55 – 85 m/h

most tests at

65 m/h4

110-150

130-160

12.4 mg Fe/l + 0,8 mg/l

7.6 mg Al/l + 0,6 mg/l

6.2 mg Fe/l + 0,6 mg/l

2.1 mg Fe/l + 0,45 mg/l

3

< 5

5

10

< 2

< 2

0.122

MBBR + Settling +

ACTIFLO®

120 m/h

100 m/h

3,5–4,5

10 - 25

13.2 mg Fe/l + 0,5 mg/l

6.0 mg Al/l + 0,6 mg/l

1.4

< 2

<0,1

>0.3

MBBR + Settling +

ACTIFLO® Turbo

90 m/h

115 m/h

115 m/h

3,5–4,5

10 - 25

13.2 mg Fe/l + 0,5 mg/l

9.6 mg Fe/l + 0,5 mg/l

9.1 mg Al/l + 0,6 mg/l

< 1

1.2

1.4

<0.1

<0.1

0.1

1Anionic polymer M155 2Lowest value achieved - at high Al dose (14.4 mg Al/l) 3Rise rate, hydraulic surface load (m3/m2 . h) calculated on the settler foot-print area

Summary of Pilot Results, Quebec, Can (John Meunier, VWS, Can)

Actiflo following MBBR• MBBR load : 4 – 25 g BOD5/m2d• Actiflo rise rate: 40 – 120 m/h• FeCl3-dose : 30 – 115 µL/L• Polymer dose : 0.5 - 1.2 mg/l

Parameter units Influent Effluent % removal

Total P (mg/L) 1 - 5 0.2 -0.7

Turbidity NTU 58 - 154 2.5 - 6.8

TSS (mg/L) 94 - 196 13 - 24 86 - 88

COD (mg/L) 176 - 361 31 - 58 82 -84

BOD (mg/L) 53 - 155 5 - 11 91 -93

pH --- 7.1 - 7.5

ExampleDrammen WWTP

InletLine 1

Line 2

Line 3

Line 4

Line 5

Line 6

1 2

1: Flocculation2: Sedimentation 3: Thickeners4: Sludge silo

Outlet

3

4

InletLine 1

Line 2

Line 3

Line 4

Line 5

Line 6

11 22

1: Flocculation2: Sedimentation 3: Thickeners4: Sludge silo

Outlet

33

44

Inlet Kaldnes MBBR® 1-1

3

1: Kaldnes MBBR®

2: DAF3: Sludge silo 3% TS4: Sludge silo 6% TS

OutletDAF 1

21

Kaldnes MBBR® 1-2

Kaldnes MBBR® 2-1 Kaldnes MBBR® 2-2

Kaldnes MBBR® 3-1 Kaldnes MBBR® 3-2

Kaldnes MBBR® 4-1 Kaldnes MBBR® 4-2

Kaldnes MBBR® 5-1

Kaldnes MBBR® 6-1

Kaldnes MBBR® 5-2

Kaldnes MBBR® 6-2

DAF 2

4

DAF 3

DAF 4

DAF 5

DAF 6

Inlet Kaldnes MBBR® 1-1

33

1: Kaldnes MBBR®

2: DAF3: Sludge silo 3% TS4: Sludge silo 6% TS

OutletDAF 1

2211

Kaldnes MBBR® 1-2

Kaldnes MBBR® 2-1 Kaldnes MBBR® 2-2

Kaldnes MBBR® 3-1 Kaldnes MBBR® 3-2

Kaldnes MBBR® 4-1 Kaldnes MBBR® 4-2

Kaldnes MBBR® 5-1

Kaldnes MBBR® 6-1

Kaldnes MBBR® 5-2

Kaldnes MBBR® 6-2

DAF 2

44

DAF 3

DAF 4

DAF 5

DAF 6

Inlet

3

4

1: Kaldnes MBBR®

2: Actiflo®

3: Thickeners4: Sludge silos 6%5: Free space (chemical handling)

Outlet

1

Actiflo® 1

Actiflo® 2

25

Kaldnes MBBR® 1-1 Kaldnes MBBR® 1-2

Kaldnes MBBR® 2-1 Kaldnes MBBR® 2-2

Kaldnes MBBR® 3-1

Kaldnes MBBR® 4-1

Kaldnes MBBR® 3-2

Kaldnes MBBR® 4-2

Inlet

33

44

1: Kaldnes MBBR®

2: Actiflo®

3: Thickeners4: Sludge silos 6%5: Free space (chemical handling)

Outlet

11

Actiflo® 1

Actiflo® 2

2255

Kaldnes MBBR® 1-1 Kaldnes MBBR® 1-2

Kaldnes MBBR® 2-1 Kaldnes MBBR® 2-2

Kaldnes MBBR® 3-1

Kaldnes MBBR® 4-1

Kaldnes MBBR® 3-2

Kaldnes MBBR® 4-2

Upgrading a chemically enhanced primary plant to become a secondary plant by the use of MBBR and ACTIFLO®

Two MBBR – ACTIFLO in Bergen Under Construction

Bergen WWTP design:

• rBOD = 11,5 g BOD5/m2d

• vf = 60 m/h(rise rate in settling zone)

0

50

100

150

200

250

300

350

Conc

entra

tion

BOD

5, m

g/L

BOD5 results Handeland WWTP 2007-2008

Influent concentration

Effluent concentration

0

5

10

15

20

25

30

35

40

0

100

200

300

400

500

600

700

800

Out

let c

once

ntra

tion,

g O

/m3

Inle

t con

cent

ratio

n, g

O/m

3

Date

BOD5 results Skreia WWTP 2005-2008

BOD5:Inlet

BOD5:Outlet

a. Handeland WWTP

b. SkreiaWWTP

Handeland, Skreia MBBR/Actiflo® Plants

MBBR-Flotation (DAF)

Historically a very popular option for compact MBBR separation in Scandinavia

Data below from the Johnstown, CO LagoonGaurd MBBR-DAF Installation

Parameter DAF influent Range Average DAF Effluent Range Average

Turbidity, NTU 18-80 40 2-28 15

BOD mg/l 24-35 27 3-13 10

TSS mg/l 19-62 35 8-25 11

Typical design values for DAF following MBBR (Ødegaard et al, 2009)

1052 – 3 m

At maximum design flow, Qmaxdim

At design flow, Qdim

Surface overflow rate (m2/m3.h)Tank depth

1052 – 3 m

At maximum design flow, Qmaxdim

At design flow, Qdim

Surface overflow rate (m2/m3.h)Tank depth

Dispersion pressure : 400 – 600 kPa (4-6 bar)Air saturation: 80 - 90 %Dispersion water flow (% of Qmaxdim) : 10 - 25 %

(depending on SSin and air saturation)

Average Results from three Scandinavian Plants using DAF after MBBR

Parameter Nordre Follo WWTP Gardermoen WWTP Sjölunda WWTP

Design values Design flow (m3/h) Max. flow (m3/h) Temp. (oC)

750 1125 6-14

920

1300 4-14

7920

15840 8-20

Plant size Tot. MBBR vol. (m3) Flocculation vol. (m3) Flotation area (m2)

3710 230 150

5790 180 215

6230 3960 2000

Year documented Average in-out conc. and treatment efficiency SS (mg/l)

BOD (mg/l) COD (mg/l) Tot N (mg/l) Tot P (mg/l)

2008 In Out % - - - 123 3.8 97 453 49 89 32 6.5 80 4.2 0.14 97

2009 In Out % - - - 274 2.2 99 725 33 95 62 8.7 85 8.8 0.11 99

2009 In Out % 282 12 96 231 10 96 559 62 89 41 10 76 5.3 0.30 94

MBBR - Microscreening

The Hydrotech Disc Filter

• Directly after MBBR or for polishing• Sieve openings: 10 – 100 µm• Operational head-loss: 10”• Backwash during operation

Disc Filter plant after post DN MBBR at Rya WWTP,Gothenburg, Sweden

Results from the Rya WWTP Discfilter(Mattson et al, 2009)

0

5

10

15

20

25

30

0 10 20 30 40 50Influent SS (mg/l)

Filtr

atio

n ve

loci

ty (m

/h)

10 micron

18 micron

Filtration rate (based on total filter mesh area) versus influent SS (Persson et al. 2006)

Feed, mg SS/l Effluent, mg SS/l Capacity, m3/m2 filter

. h Mesh pore

size, µm Average St.dev. Average St.dev. Average St.dev.

Number ofSamples

18 27.5 14.5 5.0 1.8 13.7 7.2 37

10 30.5 10.8 3.5 1.3 4.8 2.2 22

Discfilter With Chemical Dosing

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200 250 300 350

Efflu

ent S

S (m

g/l)

Influent SS (mg/l)

Gardermoen WWTP 40 micron

Nordre Follo WWTP 40 micron

Gardermoen WWTP 20 micron

Effluent SS versus influent SS without any pre-coagulation/flocculation

0

5

10

15

20

25

30

35

40

45

50

0 10 20 30 40 50 60 70 80 90 100Polymer dose (mg PE/g SS)

Efflu

ent S

S (m

g/l)

Gardermoen WWTPNordre Follo WWTP

Effluent SS as a function of polymer dosing.

Sand filtration after MBBR

Various uses:

As polishing step

Directly after nitrifying or denitrifying MBBR• Ex.: Klagshamn WWTP

8,2 m/h at Qmax

Effluent : < 5 mg SS/l, 0,2 mg P/l

Directly after high-rate (secondary treatment) MBBR-Cheyenne Crow Creek

Membrane filtration after MBBR

Different strategies tested

a.MBBR – submerged hollow fiber UF membrane (i.e. Zenon ZeeWeed)

b.MBBR – Discfilter – Contained hollow fiberUF membrane

c.MBBR – submerged membrane in reactor with settling zone

d.MBBR – DAF – Contained hollow fiber UF membrane

Conclusions

1. Particle size distribution (PSD) of biomass leaving MBBR:a. Large mass fraction of relatively large particles (30 – 300 µm), but

a high number of small particles (0.1 – 1 µm). The easiest way to deal with the latter is by coagulation ahead of the separation reactor

b. The PSD is shifted towards larger particles when the organic area load is decreasing (HRT is increasing). Hence the higher the area load, the better is the effect of pre-coagulation

2. All of the commonly used separation methods may be used.a. MBBR allows the use of a variety of separation methods providing

greater flexibility that the AS processes missb. DAF is well provenc. Microsand ballasted lamella settling (Actiflo) is of increasing

interest and results in an extremely compact plant d. A very compact solution is also achieved with the use of Discfilter

di tl ft th MBBR li hi t ti t

Final Thoughts