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FlocFormer - the best floc for every dewatering task

aquen aqua-engineering gmbh

Bauhofstrasse 31

D-38678 Clausthal-Zellerfeld

Germany

www.aquen.de

WASTEWATER RESEARCH & INDUSTRY SUPPORT FORUM , 9th July 2014

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Subjective of the project

- Controllable flocculation process -

benefits: - improvement of dewatering - improvement of separation - maximum utilisation of flocculant

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Common application Municipal waste water sludge dewatering

flocculant: polymer

pump

pump digester

chamber filter press

decanter / centrifuge

Germany: mainly centrifuges but some move back to chamber filter press to get better %DS

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Common application Pathway of conditioning for chamber filter press

polymer

stirred tank

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Common application Pathway of conditioning for chamber filter press

polymer

inline mixer

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Common application Pathway of conditioning for chamber filter press

polymer polymer

pump

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Common application Pathways of conditioning for chamber filter press

polymer

polymer

polymer

buffer tank

inline mixer

pump filter press

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Common application Conditioning for decanter / centrifuge

Polymer

digested sludge

decanter / centrifuge

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0

50

100

150

200

250

300

350

400

0 1000 2000 3000 4000 5000 6000

run length [Pixel]

0

50

100

150

200

250

300

350

400

0 1000 2000 3000 4000 5000 6000

χ =18.4 10 -6

kg 2 s

-2 m

-4 χ =1.87 10 -6

kg 2 s

-2 m

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Target: Generation of a specific floc structure adapted to the

dewatering / separation equipment

run length [Pixel]

Floc structure - The key for the dewatering process

χ = filterability [based on the CST (Vesilind, 1988)] Pixel = 40 μm

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0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

I II III IV V VI VII VIII IX X XI XII XIII XIV

T-Mixer 4.5 g/kg TS T-Mixer 5.0 g/kg TS T-Mixer 5.2 g/kg TS T-Mixer 5.3 g/kg TS T-Mixer 6.0 g/kg TS

FlocFormer 4.5 g/kg TS FlocFormer 5.0 g/kg TS FlocFormer 5.2 g/kg TS FlocFormer 5.3 g/kg TS FlocFormer 6.0 g/kg TS

Floc structure - The key for the dewatering process

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I. Network structures

II. Floc Interaction

III. Discrete Flocs IV. a Floc Erosion/

Destruction

IV. b Floc Pelleting =

good dewatering

Flocculation theory: Steps of the flocculation process

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It is not possible

to generate

a specific floc structure

with only one mixing device.

Flocculation reactor development Fundamentals

Inline Mixer n [min-1]

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It is not possible

to generate

a specific floc structure

with only one mixing device.

Flocculation reactor development Fundamentals

Inline Mixer n [min-1]

Requested

floc structure:

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Two step process: 1. Polymer mixing 2. Floc forming

Scheme of FlocFormer

Schlamm / Wasser

Spezifische Flockenstruktur

Polymer

1. Schritt Polymer Einbringung

2. Schritt Flocken Formung

floc structure of common conditioning

floc structure of FlocFormer

pelleting

The rolling motion in the gap between the rotating cone and the case improves the flocs. The sides of the gap remain parallel; width of gap adjustable. The speed of rotation of the cone is adjustable.

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Flow within the gap

(Wimmer 83)‏

Top pic = slow rotation; bottom pic = faster and better dewatering result

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Floc structure

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FlocFormer application

36 m3/h FlocFormer (5L)‏

18 m3/h FlocFormer (3L)

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Optimization of screw press

Huber ScrewPress http://www.huber.de/products/sludge-treatment/dewatering/rotamatr-screw-press-ros-3q.html and ISGK Ishigaki Screw Press www.ishigaki.co.jp

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Municipal sludge dewatering optimization of screw press - results

Poly 1

Poly 2

Poly 3

static mixer static mixer static mixer FlocFormer FlocFormer FlocFormer

Digested sludge Note: typically longer HRT in DE and consequently more VSR

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0

5

10

15

20

25

30

(WWTP Graz, Austria –anaerobic digestion)

Municipal sludge dewatering optimization of screw press - results

polymer consumption [kg/t TS] TS [%]

without FlocFormer with FlocFormer

Polyelectrolyte expressed as active ingredient Dewatering without FlocFormer was optimised by the WwTW

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Optimization of decanter centrifuge operation

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Optimization of decanter centrifuge operation

Common dewatering result – conventional poly system without FlocFormer

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Optimization of decanter centrifuge operation (digested sludge)

decanter 1 decanter 2 with FlocFormer

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2

4

6

8

10

12

14

16

18

poly

mer

con

sum

ptio

n (l/

m3

slud

ge)

dekanter 1 dekanter 2 with FlocFormer

0

5

10

15

20

25

DS

dew

ater

ed (%

)

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Optimization of decanter centrifuge operation Westfalia-Separator (WWTP Oelde) – results Effect of changing cone speed and gap

polymer consumption: 6,5 - 7,0 g/kg DS

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Optimization of decanter centrifuge operation

18.0

20.0

22.0

24.0

26.0

28.0

30.0

1 2 3 4 5

[TS

% d

ew

ate

red

slu

dg

e]

TS increasing WWTP Bremen Farge

without FlocFormer

FlocFormer/ flocculant II

FlocFormer/ flocculant I

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Sludge dewatering decanter centrifuge

FlocFormer like Digested sludge

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Optimization of belt filter press

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Optimization of belt filter press

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21.5

22

22.5

23

23.5

24

24.5

25

25.5

26T

S d

ew

ate

red

slu

dg

e [

%]

Excess sludge, WWTP Linz-Unkel, Waste Activated Sludge

without FlocFormer with FlocFormer

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Optimization of Belmer Winkelpresse (belt filter press)

WWTP Olching, Germany, digested sludge

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Optimization of chamber filter press

20.5

21

21.5

22

22.5

23

23.5

24

24.5

25

25.5

26T

S d

ew

ate

red

[%

]

(WWTP Ratekau, Schleswig Holstein)

without FlocFormer with FlocFormer

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16%

0%

5%

10%

15%

20%

25%

30%

1 2 3 4 5 6 7 8 9 10

Incre

ase

of

fillin

g f

eed

%

runs

(WWTP Colone Wahn)

Optimization of chamber filter press

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Optimization of Bucher press

WWTP Scharzfeld, Germany, 2-week test, conventional digested sludge c58%VS

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49

50

1 2

avera

ge T

S d

ew

ate

red [

%]

0

2

4

6

8

10

12

1 2

avera

ge P

oly

mer

consum

ption

[g/k

g T

S]

original Bucher inline mixer

FlocFormer conditioning

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Municipal sludge dewatering Optimization of TornadoPress, Japan

pump FlocFormer TornadoPress

The Tornado Press is similar to a Screw Press but with a vertical axis

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FlocFormer trials Kyoto and Niigata, Japan

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Municipal sludge dewatering Japan Optimization of TornadoPress operation

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2

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10

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18

20

TS

dew

ate

red

[%

]

0

5

10

15

20

25

30

Poly

mer c

on

su

mp

tion

[g

/kg

TS

]

common process

common process

FlocFormer

FlocFormer WWTP

Kyoto, Japan

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DeSiFloc COD separation for landfill leachate treatment

coagulation

Biological pre-treated leachate

effluentf

COD approx. 3.500 mg/L

COD separation

COD < 200 mg/L

FlocFormer

rotating disc thickener

COD approx. 210 mg/L

Activated carbon to assure <200 mgCOD/L, which is the requirement for discharging to river; better COD removal in the thickener extends the life of the activated-C

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DeSiFloc COD separation for landfill leachate treatment

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Flocculation and separation effort

DeSiFloc COD separation for landfill leachate treatment

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Resume

Important facts for a short payback period 1. Correct positioning of the FlocFormer in the process

FlocFormer should be immediately before the dewaterer/thickener so that the conditioning is not damaged by pumping, etc.

2. Adjustability of the dewatering/separation device

3. Choice of a adequate flocculant

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Thank you !

Contact:

christian.schroeder@aquen.de

aquen aqua-engineering gmbh Bauhofstrasse 31

D-38678 Clausthal-Zellerfeld Germany

www.aquen.de