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Swiss strategies and results from advanced wastewater treatment

Eawag: Swiss Federal Institute of Aquatic Science and Technology

ESAMUR XII Technical Conferences, Murcia, 9-10 Nov 2016

Christa S. McArdellchrista.mcardell@eawag.ch

Dept. Environmental Chemistry

WWTP size

River catchments

Swiss watershed

Switzerland~6‘000 km river stretches containing treated wastewater, 742 wastewater treatment plants (>500 PE)

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WWTP size

River catchments

Swiss watershed

Switzerland~6‘000 km river stretches containing treated wastewater, 742 wastewater treatment plants (>500 PE)

Exceedances of chronic quality criteria

Abegglen et al. 2012, BAFU report

Evaluation of 543

river stretches below

WWTPs

none

Annual average environmental quality criteria for 15 micropollutants at low water flow (Q347): www.oekotoxzentrum.chMaximal exceeded by six substances: Azithromycin, Carbamazepine, Clarithromycin,Diazinon, Diclofenac, Ibuprofen

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Development of regulation regarding micropollutants in wastewater in Switzerland

2010 2011 2012 2013

Adaptation of water protection ordinance proposed

Public consultation of ordinance

Motion of CESPE

accepted

Public consultation of water

protection act

Act accepted by parliament

80% of statements in public consultation support targeted measures –

financing solution claimed

2009

Act accepted by federal council

Development of implementation

concept

Strategy Micropoll:Analysis of situation, large scale essays in

WWTP

since 2006

10.12.2013 council of states

3.3.2014 National council

80% of statements in public consultation support

targeted measures AND financing solution

Adaptation of water protection act proposed

2014 2015

Text of new water protection ordinance proposed

Implementation of new water protection act

New Swiss water protection act (Gewässerschutzgesetz GSchG) is implemented since January 2016

Goal: Reduction of pollutant load to enhance water quality

Elimination of micropollutants to 80% in wastewater treatment (selected substances)

Installation of advanced treatment at the wastewater treatment plants:

WWTP (>80‘000 inhabitants) with high loads

WWTP (>24’000 inhabitants) in the catchment of lakes

WWTP (>8’000 inhabitants) on rivers with a fraction of wastewater greater than 10%

WWTP (>1’000 inhabitants) on rivers with impact on drinking water resources

Swiss Wastewater Treatment in the future

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Selection of Treatment technologyRequirements Elimination of a broad range of compounds No formation of problematic products Cost efficiency Good technical implementation

Project «Strategy Micropoll» (FOEN, 2006-2012)

Activated carbon adsorptionpilot plant at Lausanne

Ozonation pilot plant at Regensdorf

Cost calcuation for advanced treatment

Energy WWTPkWh/m3

Primary energykWh/m3

CostsCHF/m3

14'400 p.e.

CostsCHF/ m3

590'000 p.e.

Ozonation (5 g/m3) 0.06 0.27 0.15–0.19 0.04–0.06

Ozonation (5 g/m3)

with sand filtration0.10 0.39 0.32–0.36 0.09–0.11

PAC (10 g/m3) 0.02 0.32 0.25–0.3 0.1–0.15

PAC (10 g/m3)

with sand filtration0.06 0.44 0.42–0.47 0.15–0.2

Including amortization and operation

Current costs: 0.80 CHF/m3 for a small, 0.55 CHF/m3 for a large WWTP

cost increase for a small WWTP by 20-50% Cost increase for a large WWTP by 10-20%

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Action plan:

about 100-120 WWTPs (of 700)

Upgrade within the next 20 years

3.7 Mio. inhabitants (50% of Swiss population)

total costs of investment: 1'200 Mio. CHF

increase of annual costs for wastewater treatment: 130 Mio. CHF per year

= 10-15 % of today's costs for wastewater treatment

(15 CHF/cap/y)

Financing of 75% of investment costs:

• each Swiss inhabitant with connection to WWTP pays CHF 9 /year for 20 years (current cost: CHF 112)

Once a WWTP is upgraded: WWTP is exempted from fee, but pays 25% of investment plus operation costs

Predicted costs for Swiss WWTP upgrade

How to evaluate effectiveness?

Selection criterial for 12 substances:

o Present in all large Swiss WWTPs (person equivalent > 10’000)

o Active substances (no transformation products)

o Not eliminated by biological treatment

o Eliminated by both treatments PAC and ozonation to a similar extend

o Detectable with a reliable and ready to use analytical method

Quantitative target screening of 435 micropollutants was done to evaluate the performance of conventional and advanced wastewater treatment (PAC, ozonation)

Project: J. Otto, H. Singer et al. (Eawag); C. Götz (Envilab AG)

funded by FOEN

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Substances selected to evaluate effectiveness of measures

Substance class Elimination withozone / PAC

Amisulpride antipsychotic Very good (>80%)

Carbamazepine antiepileptic Very good

Citalopram antidepressant Very good

Clarithromycin macrolide antibacterial Very good

Diclofenac antiinflammatory / antirheumatic

Very good

Hydrochlorothiazide diuretic Very good

Metoprolol beta blocking agent Very good

Venlafaxine antidepressant Very good

Benzotriazole corrosion inhibitor good (50-80%)

Methyl-Benzotriazole corrosion inhibitor good

Candesartan antihypertensive agent, angiotensin II antagonist

good

Irbesartan dito good/ Very good

Götz et al., AQUA&GAS (2015), 2, 34-40

Selection of four substances

Selection of two substances

WWTP NeugutFirst site with advanced treatment of wastewater by ozonation, since March 2014

CAS treatment• Nitrification• Denitrification• Biological Phosphate-

removal

Primary Treatment

Ozonation:• Volume Reactor: 530 m3

• Retention times: 43 min (QTW, Average)13 min (QRW, Max)

• DOCeff: 3.5 - 6 mg/L• NO2

--N: <0.1 mg/L• PO4

2-: 0.24 mg/L

Investment costs: CHF 3.27 Mio Additional energy consumption: 0.03 kWh/m3

Additional operating costs: CHF 0.013/m3

Additional total costs: CHF 0.06/m3 (↑10%)

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Elimination of 12 substances chosen to evaluate effectiveness of advanced treatment Over the whole WWTP Neugut

McArdell et al. 2016, non-published

To eliminate on average 80% of 12 substances: Ozone dose 1.5 - 2.5 mg/L (0.40 g ozone /g DOC) sufficient Ozone dose 2.0 - 3.3 mg/L (0.55 g Ozon /g DOC) recommended

(to compensate peak values of 0.2-0.3 mg NO2-N /L).

Micropollutants in WWTP Neugut with ozonation(2.7 mg/L Ozone = 0.55 gO3/gDOC, two 48h composite samples)

Eawag LC/MS/MS screening list (550, inclusive metabolites)

> 90%

Substances in effluent > 1 µg/L:Acesulfame, Sucralose, Metformin, Iopromide

Influent Influent Effluent

WWTP ozonation WWTP

Personal care products

Caffeine, nicotine & metabolite

Food additives

Illicit drugs

Corrosion inhibitor

Industrial chemicals (incl. PFCs)

Pharmaceuticals

Pesticides

McArdell et al. 2016, non-published

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Tests to evaluate the treatability of wastewater with ozone

Modular laboratory decision tool to test the feasibility of ozonation as an option to upgrade specific WWTPs

Bromate and NDMA

Ames testcombined algae assayC. dubia reproduction test

Schindler Wildhaber, von Gunten et al. Wat Res. 2015, 75, 324

NDMA guideline value for drinking water by World Health Organization (2008): 100 ng/L NDMA prov. drinking water value Germany: 10 ng/L

Formation of ozonation by-products at WWTP Neugut

N-Nitrosodimethylamin (NDMA) :

Formation in ozonation: < 30 ng/L, but occurring in WWTP influent

Elimination in sand filter: 65%

Concentration after sand filtration: < 50 ng/L

Bromate:

Formation of Bromate: <10 µg/L at the recommended ozone dose

No elimination in post-treatment

Bromate drinking water standard from EPA (2012) und WHO (2005): 10 µg/L

GAC 3(BV 40’000)

Occurrence of NDMA:

(As proposed by Schindler, von Gunten et al. Wat Res. 2015, 75, 324)

before ozonation

after ozonation

after sand filtration

Test A Test B Test C Test Dat 0.55 g ozone / g DOC

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Ecotoxicological evaluation of different WWTPs(I): WW effluent, (II): After ozonation, (III): After ozonation and biodegradation

WWTP  A  B  C  D  E  F  G 

(I) (II)  (III)  (I)  (II)  (III) (I) (II) (III) (I) (II) (III) (I) (II) (III) (I) (II) (III) (I) (II)  (III) 

TA98‐S9  ↓ ↓ ↑ ↑ ↓ ↓ ↑ ↑

TA98+S9  ↓ ↓ ↑ ↑ ↓ ↓ ↓ ↑ ↑

TA100‐S9  ↓ ↓

TA100+S9  ↑

YG7108‐S9  ↑ ↑ ↑ ↑ ↑ ↑

YES  ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓

YAS 

Algae Phot.  ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓

Algae growth  ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓

C. dubia  n.a. n.a. ↓ ↑ ↓ ↓ ↓ ↑

Fishegg  ↑ ↓

 

Schindler Wildhaber, von Gunten et al. Wat Res. 2015, 75, 324

Ozonation not recommended

Bioassays inconspicuous

PAC/flocculant addition to a contact tank and:

PAC

recirculation of used PAC into biology

Al or Fe

PACAl or Fe PAC

PAC Treatment– potential flow schemes

PAC addition to filtration PAC additon directly to activated sludge

• Sedimentation / filtration• Flotation / filtration• Membrane separation

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0%

20%

40%

60%

80%

100%

Sulfamethoxazol

Benzotriazol

Atenolol

Diclofenac

Carbamazepin

Clarithromyzin

Mefenam

insäure

5-Methyl-Benzotriazol

Ranitidin

Venlafaxin

DHHPrim

idon

Codein

Oxazepam

Iopromid

Iohexol

Ibuprofen

Naproxen

Bezafibrat

Eli

min

atio

n

10 mgPAC/l without PAC-recycling to biology (Pilot: 8.8 mgDOC/l; ref: 8.4 mgDOC/l)10 mgPAC/l with PAC-recycling to biology (Pilot: 7.4 mgDOC/l; ref: 8.9 mgDOC/l)15 mgPAC/l with PAC-recycling to biology (Pilot: 5.5 mgDOC/l; ref: 6.7 mgDOC/l)

PAC addition to secondary effluent (with sedimentation)pilot plant Eawag

All elimination rates referring to primary effluent

0%

20%

40%

60%

80%

100%

Sulfamethoxazol

Benzotriazol

Atenolol

Diclofenac

Carbamazepin

Clarithromyzin

Mefenam

insäure

5-Methyl-Benzotriazol

Ranitidin

Venlafaxin

DHHPrim

idon

Codein

Oxazepam

Iopromid

Iohexol

Ibuprofen

Naproxen

Bezafibrat

Eli

min

atio

n

10 mgPAC/l without PAC-recycling to biology (Pilot: 8.8 mgDOC/l; ref: 8.4 mgDOC/l)10 mgPAC/l with PAC-recycling to biology (Pilot: 7.4 mgDOC/l; ref: 8.9 mgDOC/l)15 mgPAC/l with PAC-recycling to biology (Pilot: 5.5 mgDOC/l; ref: 6.7 mgDOC/l)

0%

20%

40%

60%

80%

100%

Sulfamethoxazol

Benzotriazol

Atenolol

Diclofenac

Carbamazepin

Clarithromyzin

Mefenam

insäure

5-Methyl-Benzotriazol

Ranitidin

Venlafaxin

DHHPrim

idon

Codein

Oxazepam

Iopromid

Iohexol

Ibuprofen

Naproxen

Bezafibrat

Eli

min

atio

n

10 mgPAC/l without PAC-recycling to biology (Pilot: 8.8 mgDOC/l; ref: 8.4 mgDOC/l)10 mgPAC/l with PAC-recycling to biology (Pilot: 7.4 mgDOC/l; ref: 8.9 mgDOC/l)15 mgPAC/l with PAC-recycling to biology (Pilot: 5.5 mgDOC/l; ref: 6.7 mgDOC/l)

Böhler et al., Wat. Sci. Technol. 2012

Comparison of PAC and ozone treatment: Elimination in hospital wastewater treatment

Average elimination:Contrast othersmedia

PAC 61% 86%Ozone 50% 90%

Eli

min

atio

n w

ith

23

mg

PA

C/L

[%

]

Elimination with 1 gO3/gDOC [%] Kovalova, ES&T 2013

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Facts, benefits and limitations of treatments

Facts and Benefits Limitations

OzoneTreat-ment

2-5 mg/L O3 (0.6-0.9 gO3/g DOC) necessary (depending on Q and DOC)

10 min retention time required (20-40 min at dry weather conditions)

Most substances are oxidized Partial disinfection Reduction of color

The substances are transformed to mostly unknown transformation products

Post-treatment with biological activity needed

Formation of oxidation by-products (e.g. NDMA, bromate from bromide)

High energy demand from ozone production

Regulation of ozone dose is crucial Safety measures (toxic O3)

PAC

10-20 mg/L necessary for 5-10 mg DOC/L

20-30 min hydraulic retention time 1-2 days PAC retention time

needed Most substances are removed removal of substances (not just

transformation) Reduction of color Up to 40% DOC removal

PAC must be disposed. Incinerationmight provide bromide.

Post-treatment required (textile or sand filter) to reduce discharge of PAC

production of PAC needs high energy Recirculation into biology improves

elimination (10-50%) but also increases sludge production (5-10%)

Safety measures (respiratory protection)

Places in Switzerland / Germany / Austria / France with advanced wastewater treatment

VSA platform «Process Engineering Micropollutants» (www.micropoll.ch): Communication and information

Country PAC (Ulm)

GAC Ozone

Switzerland 1 - 1

Germany 11 3 2

France - - 4

Total 12 3 7

OzonePAKGAK

As of October 2016

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Conclusions

An efficient and cost- effective elimination of micropollutants can be achieved with ozonation or sorption to activated carbon (PAC or GAC-filter)

For the treatment of 50 % of the wastewater in Switzerland, the annual costs increase was calculated to be 10-15 % (15 CHF/cap/y)

A post-treatment after ozonation and PAC treatment is needed

To evaluate the effectiveness of advanced wastewater treatment, 12 substances were selected which need to be eliminated by 80%

Problematic by-products (NDMA, bromate) need to be considered for ozone treatment

Toxicity of ozonation transformation products and by-products need to be evaluated with bioassays

Acknowledgement

Co-workers at Eawag: Marc Böhler, Marc Bourgin, Ewa Borowska, Birgit Beck, Julian Fleiner, Juliane Hollender, Elisabeth Salhi, Hansruedi Siegrist, Rebekka Teichler, Urs von GuntenAnd at Ecotox Center Eawag-EPFL: Cornelia Kienle, Miriam Langer

WWTP Neugut, Dübendorf, www.neugut.ch

www.demeau-fp7.eu (EU Grant no. 308339)

Project MICROZO (Nr. 12.333)FOEN Projects UV and ReTREAT

Information:o DEMEAU deliverable D32.3 “Decision basis for implementation” o VSA platform: www.micropoll.cho Christa.mcardell@eawag.ch