TREATING MICROPOLLUTANTS OF EMERGING CONCERNuest.ntua.gr/iwwatv/proceedings/presentations/22... · Applied ozone (mg) TCS removal (%) Ozone dose (mg/L) 10 mn 5 min 1 min 10 mn 5 min

May 21-23, 2015 Athens

TREATING MICROPOLLUTANTS OF EMERGING CONCERN:

A CASE OF TRICLOSAN

Filiz B. Dilek Middle East Technical University

Dept. of Environmental EngineeringAnkara, Turkey

Industrial Waste & Wastewater Treatment & Valorization


Biocide!to preserve materials including food, to decontaminate

surfaces, for personal hygiene...

• CAS Number: 3380-34-5• Partition coefficient (Octanol/Water); log KOW = 4.76• Molecular weight = 289.54 g/mol• Density = 1.55 ± 0.04 g/cm3

• Solubility in water = 1 mg/L @ 20°C• Vapor Pressure = 4 x 10-6 mmHg at 20°C

Triclosan (TCS) …


• Produced since 1965

• Production of 10-1000 tones per year only in Europe

• Consumption changes from country to country with a total 450tones/yr

Production and use around the world …


It is everywhere …

Presenter

Presentation Notes


Not hazardous to humans, but skin, eye and respiratory irritations, allergy susceptibility and inhalation toxicityMight be harmful to the immune system Alters hormone regulation in animals-Endocrine distruptioneffects! Toxicity on biota

Bioaccumulation due to its hydrophobic nature –

BCF: 3700-8400 for fish speciesMight contribute to the development of antibiotic-resistant germs

http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/triclosan/faq-20057861http://www.fda.gov/forconsumers/consumerupdates/ucm205999.htm

Adverse Effects?

http://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/triclosan/faq-20057861


• Exposure to low levels of TCS disrupts thyroid hormoneassociated gene expression and can alter the rate of thyroid hormone-mediated postembryonic anuran development.


Not hazardous to humans, but skin, eye and respiratory irritations, allergy susceptibility and inhalation toxicityMight be harmful to the immune systemAlters hormone regulation in animals-Endocrine distruptioneffects!Toxicity on biota




Adverse Effects?



TCS affected both bacterial and algal communities within the biofilm, although TCS toxicity was higher for bacteria than algae (NEC: 0.21 µg/L for bacteria; 0.42 µg/L for algae).

The potential environmental risk of TCS is high especially in rivers where water scarcity results in low dilution capacity, like in Mediterranean areas.


Not hazardous to humans, but skin, eye and respiratory irritations, allergy susceptibility and inhalation toxicityMight be harmful to the immune system Alters hormone regulation in animals-Endocrine distruptioneffects! Toxicity on biota




Adverse Effects?



TCS could exert a selective pressure able to drive the spread of a resistance determinant in a human pathogen – Biocide resistance

However,

No statistical correlation between reduced susceptibility to TCS and any antibiotic resistance!

EC project KBBE-227258 BIOHYPO (2013), which is a research project aimed at evaluating the impact of biocide use on the generation of antibiotic resistance


Legislative Acts

• Directive 76/768/EEC (Annex VI)

Maximum authorized concentration: 0.3% in cosmetic products !

• Directives 98/8/EC (528/2012), 95/2/EC and Regulation (EC)1831/2003

Not allowed to be used as disinfectant and preservative in foodand feed production !

Country Level Acts

• Germany introduced a ban on the use of TCS within the plasticproducts having a direct contact with foods since September 2009.

Restriction on use …


TCS(ng/L) (µg/kg)*

Surface waters 0.16-2300 BIOHYPO, 2012

Kolpin et al., 2002 Mezcua et al., 2004

Svensson, 2002 Ying -Kookana, 2007

etc.

Marine waters 16.2-99.3

WWTP influent <0.87-562000

WWTP effluent 100-269000

WWTP sludge 28-37189 *

TCS accumulates in sludge !

Environmental Occurence …


Adsorption to ozonation system

TCS decrease in identical reactors after 5 h – But, adsorption on glass reactor surface was negligable

0

1

2

3

4

5

6

0 1 2 3 4 5 6TC

S C

once

ntra

tion

(mg/

L)

Time (h)

Glass tubing

Plastic tubing

TCS concentration in glass reactors aerated with plastic or glass tubing (TCS spiked at 5 mg/L)

(without ozone gas, but air)

For ozonation tests, it is definitely advised to use glass reactors with glass tubing if possible


Adsorption to membrane filtration system

0100200300400500600700800

0 20 40 60 80 100 120 140TCS

conc

entra

tion

(µg/

L)

Time (h)

0

200

400

600

800

1000

0 20 40 60 80 100 120 140TCS

conc

entra

tion

(µg/

L)

Time (h)

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100 120 140TCS

conc

netra

tion

(µg/

L)

Time (h)

(NF system - without membrane)

It is essential firstly to saturate the system with TCS without membrane and then to carry out actual runs.

747 µg/L TCS

898 µg/L TCS

1268 µg/L TCS


REMOVAL OF TCS FROM WASTEWATER

BIOLOGICAL TREATMENT

Effect of Culture Acclimation on the Fate of Triclosan During Biological Wastewater Treatment


Acclimated cultureInfluent TCS

Concentration COD Removal (%)

0 94.0

100 ng/L 93.0

100 µg/L 92.6

500 µg/L 91.0

1 mg/L 84.4

10 mg/L 81.2

20 mg/L 67.6

50 mg/L 57.8

100 mg/L 47.4 TCS > 100 mg/L toxic effects! Positive effect of acclimation !

Influent TCS

Concentration (mg/L)

COD Removal

(%)

0 94.0

1 66.0

10 62.8

20 58.4

50 57.2

100 42.2

Non- acclimated culture

Pulse-fed sequencing batch reactor


Acclimated culture Non-acclimated culture

Main TCS removal mechanism: Biodegradation for acclimated Adsorption becomes more prominent for non-acclimated

0.00.10.20.30.40.50.60.70.80.91.0

2 20 40 100 200

Dis

trib

utio

n

Influent TCS as Mass (mg)

TCS Biodegraded

TCS in Effluent

TCS in Sludge



By-product formation

Parent compound: TCS

BP2: 2,4-DCABP1: 2,4-DCP



By-product formation

e.g. Non-acclimated culture-10 mg/L TCS (effluent water)

2,4-DCA has not been reported before.Me-TCS was not detected in both culture cases (owing to TCS stock solution prepared in NaOH)

So, one should be very careful in reporting Me-TCS as a by-product of TCS degradation without considering this fact

Acclimation resulted in lower by-product levels



In the presence of biodegradable COD


Reduced COD removal efficiency with higher TCS input ! TCS did not interfere with biodegradable COD use as long as < 20 mg/L !

0.0

0.2

0.4

0.6

0.8

1.0

0 5 10 15 20 25

CO

D/C

OD

o

Time (h)

1 mg/L TCS 10 mg/L TCS


100 mg/L TCS

0.0

0.2

0.4

0.6

0.8

1.0

0 5 10 15 20 25

CO

D/C

OD

oTime (h)



100 mg/L TCS

Kinetics



Substrate inhibition for non-acclim. culture Reduced inhibition for acclim. culture and substrate inhibition was in approach to the

Monod Model !

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0 20 40 60 80 100

µ (1

/h)

TCS (mg/L)

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0 20 40 60 80 100

µ (1

/h)

TCS (mg/L)

In the absence of biodegradable COD

Kinetics


REMOVAL OF TRICLOSAN FROM SURFACE WATERS

OZONATIONNANOFILTRATION

Ankara

Kesikköprü Dam


TCS levels in surface waters: 0.65–48.96 ng/LTCS levels in the distribution network: below LOQ


Ozonation


0102030405060708090100

0

50

100

150

200

250

300

350

400

5 10 15 24 70

TC

S re

mov

al (%

)

App

lied

ozon

e (m

g)

Ozone dose (mg/L)

10 min 5 min 1 min 10 min 5 min 1 minOzonation time (for mg) Ozonation time (for %)

about 99% TCS removal in 10 min5 min ozone : almost complete abatement (except 5 mg/L)

Effect of Ozone Dose


initial TCS: 1 mg/L, ozone dose: 5 mg/L

t=0

t=10

t=5

t=20 t=30

OH

OH

Cl

Cl

Cl

OH

Undefined t=1

2,4-DCP & 4-CC comply with Chen et al. ( 2012)

Ozonation by-products of TCS


Therefore, in ozonation studies being worked with any methyl containingsolutions or solvents, this issue should be considered cautiously.

with methanol

with NaOH

2,4-DCA is formed in the presence of methanol in water.


Proposed reaction pathway for ozonation of TCS


• Although almost complete TCS depletion in 10 min, ozoneconsumption continued due to the presence of its ozonationby-products (i.e. 2,4-DCP, 4-CC, 2,4-DCA)

Time (min)

O3 consumed/TCS (mg/mg)

Removal

(%)1 2.311 96.05 4.036 98.5

10 6.390 10020 9.841 10030 13.036 100

For complete removal!

Ozone Demand of TCS


Membrane used

Membrane Name Polymer Structure pH Range Rejection Size Typical Flux/psi GFD@PSI

DL-NF Thin Film 2-11 96 -MgSO4 31/100

Nanofiltration


Surface water spiked with 5000 ppb TCS (TMP:6.9 bar; CFV: 1.2 m/sec)


TCS removal from surface water spiked with 5000 ppb TCS

PhaseSystem Sorption Nanofiltration

TCS Concentration (ppb)Initial feed 4626 1862Steady-state feed 1862 1160Steady-state permeate NA 798

TCS Removal (%)Total 60.1 57.1By membrane sorption NA 37.7 (66)By surface rejection NA 19.4 (34)


TCS= 2000 ppb, HA: 10 mg C/L;

TCS= 5000 ppb, HA: 10 mg C/L;

TCS= 5000 ppb, HA: 26 mg C/L)

TMP:6.9 bar; CFV: 1.2 m/sec

Effect of HumicAcid (HA) as NOM

HA injected


Schematic of processes controlling the permeation of small organics

E. Steinle-Darlinga, M. Zeddab, M. H. Plumleea, H.F. Ridgwaya, M. Reinharda, Evaluating the impacts of membrane type, coating, fouling, chemical properties and water chemistry on reverse osmosis rejection of seven nitrosoalklyamines, including NDMA, Water Res. 41 (2007) 3959 – 3967


Effect of HA concentration on TCS retention (TCS:5000 ppb)

NOM had a positive effect on TCS removal (due to TCS-HA complex formation)NOM leads to an increase in TCS removal mainly by sorption into the membrane


Effect of HA concentration on flux and flux decline (TCS:5000 ppb)

Positive effect of HA on membrane fouling!Concentration polarization disappeared with anincrease in HA


• Significant TCS removal in ASP• Acclimation has a positive effect• By-products of 2,4-DCP and 2,4-DCA, but with lower levels with

acclimation

Remarks- wastewater


Ozonation:

• Very effective

• By-products of 4-CC, 2,4-DCP and 2,4-DCA

NF:

• NOM content is a factor in TCS removal from surface water by NF

• TCS removal increases with NOM

Remarks – surface water


Supported by EC project KBBE-227258 BIOHYPO and the Scientific and Technological Research Council of Turkey

(TUBITAK–1112Y210) project

Dr. Ulku Yetisand

Dr. Levent Yılmaz, Dr. Erkan Sahinkaya, Aybala K.Orhon, K. Berk Orhon, Abdullah Oğutverici

THANKS...

Documents

TREATING MICROPOLLUTANTS OF EMERGING CONCERNuest.ntua.gr/iwwatv/proceedings/presentations/22... · Applied ozone (mg) TCS removal (%) Ozone dose (mg/L) 10 mn 5 min 1 min 10 mn 5 min