Removal of pharmaceuticals in different

activated sludge wastewater treatment

plants in comparison to biofilm and

ozonation

1

Kai Bester, Aarhus University

VERSITET

Micro-pollutants in activated sludge treatment

Inflow Sludge treatment effluent

sludge

Partition

ing

Deg

ra-

dat

ion

Metabolites?

Micro-pollutants in activated sludge treatment II

Typically 10 g/L sludge are generated

If lg partition constant is 3: 50% of compound is in sludge

If lg partition constant is 4: 90% of compound is in sludge

lg partition constant = pKow

Degradation

O

OH

OH

O

OH

Ibuprofen

Hydroxy-Ibuprofen

CO2, H2O, Biomass

Degradation

Are all sludges similar?

Systematic comparison of different sludges

• Sludges were sampled at the respective WWTP

• They were used in lab for incubation studies under normalised aerobic conditions

• Samples were taken and analysed for pharmaceuticals – for kinetic data

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

WWTPs used:

Name PE COD/

BOD

Temp [oC]

SRT [d]

HRT [h]

VS [g/L]

N P

Aalborg-West

300.000 2.7 12 14 22 2.45 Alternating DN in aeration

Biological- sidestream hydrol.

Aalborg- East

100.000 2.9 11 31 35 3.17 Alternating DN in aeration

Biological- sidestream hydrol.

Aabybro 11.000 2.1 11 47 21 4.51 Upstream DN FeSO4

Hirtshals 62.700 2.0 7 20 42 3.93 Alternating DN in aeration

Biological- upstream hydrol.

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

First order reaction rate constants WWTP Compounds Degradation rate k Half-Life R2

% h-1 [h-1]

Aalborg West

Naproxen 90 0.0196 15 0.85

Ketoprofen 90 0.0079 36 0.79

Fenoprofen 90 0.0407 7 0.90

Carbamazepine - - - -

Triclosan 85 0.0065 44 0.97

Dichlofenac - - - -

Aalborg East

Naproxen 46 0.0026 86 0.67

Ketoprofen 77 0.0082 27 0.85

Fenoprofen 55 0.0088 25 0.92

Carbamazepine 82 - 70 0.45

Triclosan 61 0.0022 100 0.94

Dichlofenac - - - -

Aalbybro

Naproxen 62 0.0278 6 0.77

Ketoprofen 78 0.0112 14 0.77

Fenoprofen 65 0.0087 18 0.84

Carbamazepine - - - -

Triclosan 85 0.0038 40 0.97

Dichlofenac - - - -

Hirtshals

Naproxen 90 0.0132 13 0.91

Ketoprofen 94 0.0125 14 0.96

Fenoprofen 90 0.0813 2 0.83

Carbamazepine - - - -

Triclosan 91 0.0044 40 0.98

Dichlofenac - - - -

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

Degradation of Fenoprofen in in sludge from four different WWTPs (AAL : Aalborg).

-3.00

-2.50

-2.00

-1.50

-1.00

-0.50

0.00

0.50

0 5 10 15 20 25 30 35

Ln（

C/C

0)

Time (hours)

Hirtshals AAL East Aabybro AALWest

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

Degradation rate k in dependence of biomass expressed as volatile solids (VS).

0

0.01

0.02

0.03

0.04

2 3 4 5

De

grad

atio

n R

ate

K (

h-1

)

Volatile Solids (g/L)

Naproxen

Ketoprofen

Fenoprofen

Triclosan

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

Degradation rate k as a function of sludge retention time (SRT).

0

0.01

0.02

0.03

0.04

0 10 20 30 40 50

De

grad

atio

n R

ate

K (

h-1

)

Sludge Retention Time (days)

Naproxen

Ketoprofen

Fenoprofen

Triclosan

Chen, Vollertsen, Lund Nielsen, Gieraltowska Dall, Bester, Ecotoxicology, 24, 2073–2080, 2015

Status on sludge

• Classical activated sludge can degrade some compounds

• It is difficult to predict which plant will be able to remove how well.

• Some compounds cannot be removed (Diclofenac, Carbamazepine, X-ray contrast media)

• Diclofenac and Carbamazepine can be removed with polishing ozonation, while X-ray contrast media cannot

• Ozonation is energy craving

• What can be achieved with biofilms?

Biofilm reactors – porous media

Grains

Biofilm

Biofilm reactors – Moving bed biofilm reactor (MBBR)

Staged aerobic MBBR

• 21/26 compounds degraded >20%

• First order kinetics for most compounds

• Two phase kinetics for four compounds

• While M1 degrades faster, has M3 usually the more effective biomass

Escola Casas, Chhetri, Ooi, Hansen, Litty, Christensson, Kragelund, Andersen, Bester, Water Research, 83, 293-302, 2015

Including removal for Diclofenac, Carbamazepine, X-ray contrast compounds

Single stage denitrifying MBBR

0.0

0.2

0.4

0.6

0.8

1.0

Rela

tive c

on

cen

trati

on

Sulfamethoxazole

Sulfamethizole

Trimethoprim

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

Sta

rt e

xper

imen

t

Time (d)

Rela

tive c

on

cen

trati

on

0.2

0.4

0.6

0.8

1.0

Atenolol

Metoprolol

Sotalol

Propranolol

Sta

rt e

xper

imen

t

Time (d)

0.0

0.2

0.4

0.6

0.8

1.0

0

50

100

150

200

250

MeOH-fed MBBR

Ss depleted

Rela

tive c

on

cen

trati

on

0

50

100

150

200

250Erythromycin

Clarithromycin

sCOD

SS

EtOH-fed MBBR

Ss depleted

mg

CO

D L

-1

0.0

0.2

0.4

0.6

0.8

1.0R

ela

tive c

on

cen

trati

on

Citalopram

Venlafaxine

Carbamazepine

0.0

0.2

0.4

0.6

0.8

1.0

Rela

tive c

on

cen

trati

on

Iomeprol

Iohexol

Diatrizoic acidIopamidol

Iopromide

0.0

0.5

1.0

1.5

Rela

tive c

on

cen

trati

on

Acetyl-Sulfadiazine

Sulfadiazine

a

b

c

d

e

f

Torresi, Escola Casas, Polesel, Plósz, Christensson, Bester 2016, Water Research, in press

0.0

0.2

0.4

0.6

0.8

1.0

Rela

tive c

on

cen

trati

on

Sulfamethoxazole

Sulfamethizole

Trimethoprim

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

Sta

rt e

xper

imen

t

Time (d)

Rela

tive c

on

cen

trati

on

0.2

0.4

0.6

0.8

1.0

Atenolol

Metoprolol

Sotalol

Propranolol

Sta

rt e

xper

imen

t

Time (d)

0.0

0.2

0.4

0.6

0.8

1.0

0

50

100

150

200

250

MeOH-fed MBBR

Ss depleted

Rela

tive c

on

cen

trati

on

0

50

100

150

200

250Erythromycin

Clarithromycin

sCOD

SS

EtOH-fed MBBR

Ss depleted

mg

CO

D L

-1

0.0

0.2

0.4

0.6

0.8

1.0

Rela

tive c

on

cen

trati

on

Citalopram

Venlafaxine

Carbamazepine

0.0

0.2

0.4

0.6

0.8

1.0

Rela

tive c

on

cen

trati

on

Iomeprol

Iohexol

Diatrizoic acidIopamidol

Iopromide

0.0

0.5

1.0

1.5

Rela

tive c

on

cen

trati

on

Acetyl-Sulfadiazine

Sulfadiazine

a

b

c

d

e

f

Single stage denitrifying MBBR

• Denitrifying MBBR is nearly as effective as aerobic

• MeOH reactor does a bit better than the EtOH reactor

• Diclofenac cannot be degraded under denitrifying conditions

• Carbamazepine and X-ray contrast compounds can be degraded under denitrifying conditions

Torresi, Escola Casas, Polesel, Plósz, Christensson, Bester 2016, Water Research, in press

Conclusions:

• MBBRs might be a suitable alternative for removing organic micro-pollutants

• Co-degradation and starvation are most probably the most relevant process.

• Currently residence times of 20 h would be needed to break down sufficient amounts of pollutants

• It is difficult to foresee reactor parameters for fully optimised co-degradation/starvation reactors

Acknowledgement

All the students and collaborators that helped moving these themes forward: Xijuan Chen, Monica Escola Casas, Haitham El-taliawy, Gordon Ooi, Kai Tang, Elena Torresi

Founding: MST, MUDP, DFF-FTP, AUFF, Havs och Vatten Myndigheden

Collaboration partners: AAU, DTU, ANOX Kaldnes, Kruger, TI, Aarhus Vand,

Herning Vand, Biofos

20

CAS Ozonation Biofilm

X-ray contrast media

Beta-blockers

Diclofenac/ Carbamazepine

?

Ibuprofen

Sulfonamides :-/

Macrocyclic antibiotics

?

Persistence of compound groups in

wastewater treatment