PHOSPHORUS RECOVERY FROM DRIED SLUDGE WITH REACTIVE EXTRACTION TO REMOVE IMPURITIES

(1)

We deliver Phosphorus made in

Europe

PHOSPHORUS RECOVERY FROM DRIED SLUDGE WITH

REACTIVE EXTRACTION TO REMOVE IMPURITIES

5th ECSM, 08.10.19, Liège, Belgium

Shariff Z.A., Fraikin L., Léonard A., Pfennig A.

(2)

agenda

• PULSE process concept

• process development

– SLE modelling

– cascaded option tree

• experimental results

• summary

(3)

PULSE (Phosphorus University of

Liege Sludge Extraction) process

acid

organic

solvent

base/Ca

drying

leaching

separation

reactive

extraction

re-extraction

CaP

solid

waste

metals

precipitation

dewatered

sludge

waste

water

re-extraction

agent/NH

P + impurities

(4)

solid-liquid-liquid equilibrium

• aqueous phase speciation:

– mass balance

– law of mass action

– charge balance

• solid precipitation:

– saturation index

• activities instead of concentration to account for ionic

interactions

• degree of reactive extraction with organic solvents

(5)

solid-liquid-liquid equilibrium

-1

0

1

2

3

4

5

6

7

8

9 1E-6

1E-5

1E-4

0.001

0.01

0.1

1 CaHPO

₄

FeCl

4-FeHPO

Fe

2+

PO

₄

3-CaHPO

₄

(S)

AlPO

₄

(S)

FePO

₄

(S)

CaH

₂

PO

4+

FeH

₂

PO

₄2+

H

₃

PO

₄

H

₂

PO

4-HPO

₄

2-FeH

₂

PO

4+

Ca

2+

Cl

-Al

3+

Fe

3+

con

cen

tra

tion

mo

l/l

pH

(6)

solid-liquid-liquid equilibrium

0

1

2

3

4

5

6

7

8

9

10

11

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0 estimated log K

_extraction

= 3.2

2)

model

measured

de

gr

ee

of

iro

n e

xtra

ction

Cl

-

concentration mol/L

(7)

cascaded option tree: drying

P-recovery

from sludge

drying

conditions

-

_{dewatered sludge}

_{0 0 0}

-+

_{convective air drying}

_{+ 0 0 0 0}

slow drying (no air)

+

+ 0 0

extraction compatibility

filtrability

P leaching

operation cost

transport/handling/storage

-

_{not feasible}

0 acceptable

+ good

not evaluated

Bednarz, A. et al. 2014

dried

sludge

dewatered

sludge

(8)

P leaching- different acids and pH

-1

0

1

2

3

4

5

6

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7 de

gr

ee

of

P lea

ching

equilibrium pH

HCl

H

₂

SO

₄

HNO

₃

HCl+HNO

₃

HCl+H

₂

SO

₄

HNO

₃

+H

₂

SO

₄

H

₃

PO

₄

model

(9)

sludge leach liquor

P Fe K Mg Ca Al Mn Zn Na Cr Cu Ni Co Pb Cd

0.1

1

10

100 1000

10000

cen

tra

tion

(m

g/L

) in

lea

ch liq

uo

r

H2SO4

HCl

(10)

reactive extraction with HCl

conc. 1mol/L

D2EP

HA

_TBP

HA

-TBP

A33

6 6-

D2EP

HA

A33

6-

TB

P

HA

-TBP

0

20

40

60

80

100 pe

rc

en

ta

ge

o

f e

xt

ra

ct

io

n

P

Ca

Cd

Cu

Pb

Zn

Fe

(11)

reactive extraction of Fe with

A336 + TBP

1

2

3

4

5

6

7

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0 extraction without H

₂

O

₂

extraction with H

₂

O

₂

de

gr

ee

of

iro

n e

xtra

ction

-

Alamine 336:

𝐹𝑒𝐶𝑙

₄

−

+

𝑅

₃

𝑁𝐻

+

𝐶𝑙

−

=

𝐹𝑒𝐶𝑙

₄

𝑅

₃

𝑁𝐻+

𝐶𝑙

−

TBP:

𝐹𝑒𝐶𝑙

₄

−

+

𝑇𝐵𝑃=

𝐹𝑒𝐶𝑙

₄

𝑇𝐵𝑃

(12)

PULSE product

Comp.

Conc.

P

₂

O

₅

29.2%

CaO

21.7 %

Total C

6 %

Al

₂

O

₃

2.61 %

MgO

1.84 %

Fe

0.325 %

Mn

10800ppm

Cr

1530 ppm

Cu

294 ppm

Ni

51.6 ppm

Pb

38,8 ppm

Zn

8.97 ppm

Cd

0.735ppm

leaching of dried sludge

filtration

metal removal by reactive

extraction

CaP precipitation with NaOH

(pH = 6 - 7)

(13)

summary

• no significant difference between P leaching from wet

or dry sludge

• P leaching depends only on pH and not on the type of

acid

• extraction of metals at low pH only achieved with

Alamine 336

• metals concentration in product is within the limits set

by the EU fertilizer regulations except in case of Cr

(14)

acknowledgements

• funding

– Interreg North-West Europe

– SPW Région Wallonne

• analytics

– Faculty of Bioscience Engineering, Ghent University,

Belgium

(15)

PHOSPHORUS RECOVERY FROM DRIED SLUDGE WITH

REACTIVE EXTRACTION TO REMOVE IMPURITIES

5th ECSM, 08.10.19, Liège, Belgium

Shariff Z.A., Fraikin L., Léonard A., Pfennig A.

za.shariff@uliege.be

(16)

references

• http://www.nweurope.eu/projects/project-search/phos4you-phosphorus-recovery-from-waste-water-for-your-life/