Overview of applications of the
HYDRUS constructed wetland
moduleUniversity of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Günter LangergraberInstitute of Sanitary Engineering andWater Pollution Control
28 March 2008
HYDRUS User Workshop, Prague

28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

1

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber2

Introduction

Content

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Constructed wetlands (CWs) or wetland treatment systems

Introduction – constructed wetland technology
Simulation of constructed wetlands
Fundamentals
The multi-component reactive transport module CW2D
Simulation results
Summary and Conclusions

28.03.2008

28.03.2008

 CWs are wetlands designed to improve water quality.
 CWs use the same processes that occur in natural wetlands but have the flexibility of
being constructed.
 CWs are used successfully with different quality of the influent water and under various
climatic conditions
 CWs are effective in treating organic matter, nitrogen, phosphorus, and additionally for
decreasing the concentrations of heavy metals, organic chemicals, and pathogens.

3

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Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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1

Constructed Wetland Technology

Constructed Wetland Technology
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

In general the use of CWs provides a relatively simple, inexpensive,and robust solution for the treatment of water. Compared to other treatment options CWs
usually need less operation and maintenance expenses.
Additional benefits include their tolerance against fluctuations of flow and pollution load,
the facility of water reuse and recycling, the provision of habitat for many wetlandorganisms, and the more aesthetic appearance of a natural system compared to technicaltreatment options.

Surface Flow Constructed Wetlands

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

The role of the plants:
 The most important effects of macrophytes are physical effects.
 The amount of nutrients that can be removed by harvesting is generally insignificant(compared to the loadings with wastewater).
 Plants also have other functions e.g. provision of habitat for wildlife and giving thetreatment system a more aesthetic appearance.
28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Constructed Wetland Technology
Subsurface Flow Constructed Wetlands – Horizontal flow

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Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Constructed Wetland Technology
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

7

Subsurface Flow Constructed Wetlands – Vertical flow

28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

82

Constructed Wetland Technology

Constructed Wetland Technology
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Applications

Wastewater treatment
 domestic wastewater-

main (SSF) or tertiary (SF+SSF) treatment stage- pre-treatment, HF or VF SSF CW
 industrial wastewater-coal and metal mining waters, refinery effluents, oil-sand processing water, pulp
and paper industry, food processing wastewater agricultural wastewater

CW Kroisbach(Upper Austria)– 40 p.e.

 hospital wastewater
Stormwater and runoff management, Surface water treatment, Landfill leachate, …

28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation of Constructed Wetlands

10

Simulation of Constructed Wetlands
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Fundamentals

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

28.03.2008

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Fundamentals
Migration Models

 Migration processes are all physically, chemically and biologically caused transport,
storage, exchange and transformation processes of heat and solutes in the soil andgroundwater zoneWhy?
 better understanding of the processes within the black box the black box "constructedwetland"

Flow model(Quantity model)

 optimisation of the design of constructed wetlands.
up to now: only ”rules of thumb”, e.g. 5m²/p.e. for VF-CW (ÖNORM B 2505, 1997) and
4m²/p.e. for VF-CW (ÖNORM B 2505, 2005), respectivelycTρ( c,T)ν (c,T)vc.δφ/ tw
28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

1128.03.2008

.....
.....
.....
.....
.....
.....
.....

ρ (c,T), ν (c,T)
v, c.δφ /δt,w

Transport model(Quality model)

concentration
temperaturedensity
kinematic viscosity
flow rate
alterations storage
internal flow sources and sinks

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

123

Simulation of Constructed Wetlands

Simulation of Constructed Wetlands
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Fundamentals

Flow model – Richard’s Equation

Transport model∂ Θ ⋅ ci ∂ ρ ⋅ s i= ∇ ⋅ (Θ ⋅ Di ⋅ ∇ci ) − ∇(q ⋅ ci ) +
+


∂ t
∂ t
dispersion
convection⎛⎞⎤∂ θ (h ) ∂ ⎡∂ h=⋅ ⎢ K (h ) ⋅ ⎜ K ijA+ K izA ⎟⎥ − S⎜⎟⎥∂t∂ xi ⎢⎣∂ xj⎝⎠⎦

and diffusionsi =Θ(h) = volumetric water content;h = pressure head;S = source/sink term;xi (i=1,2) = spatial coordinates;
K(h) = unsaturated hydraulic conductivity function
KijA = components of the dimensionless anisotropy tensor KA
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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13

+ ri

βi
β

1 + ηi ⋅ ci i

28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation of Constructed Wetlands
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Fundamentals

ks ,i ⋅ ci

S ⋅ c S ,isources and sinks

c ... concentration in the solute phases ... concentration in the adsorbed phase

Simulation of Constructed Wetlands

Transport model (cont’d)

The multi-component reactive transport module CW2D

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Overview

R

R

j =1

j =1

 describes biochemical transformation and elimination processes for carbon,
nitrogen and phosphorusri = θ ⋅ ∑ν j ,i rc j + ρ ⋅ ∑ν j ,i rs j

 micro-organisms play the major role comprises 9 processes and 12 components
 is based on the mathematical structure of the Activated Sludge Models (Henze etal., 2000)

N = number of species ; i = 1..N
R = number of processes; j = 1..R
υj,i = stoichiometric factor for species i process j
rcj = zero-order reaction rate for process j (aqueous phase)
rsj = zero-order reaction rate for process j (adsorbed phase)
28.03.2008

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Fundamentals

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber is introduced into the variably-saturated water flow and solute transport program
HYDRUS-2D (finite-elements, Simunek et al., 1999)15Langergraber, G. (2003): Simulation of subsurface flow constructed wetlands - Results and further researchneeds. Water Science & Technology 48(5), 157-166.



Langergraber, G., Šimůnek, J. (2005): Modeling variably-saturated water flow and multi-component reactive
transport in constructed wetlands. Vadoze Zone Journal 4(4), 924-938.

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4

CW2D stoichiometric matrix

Material and methods

R

The multi-component reactive transport module CW2D

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Components

Processes

 dissolved oxygen [mg O2/l], readily and slowly biodegradable, and inert
OM [mg COD/l],
 ammonia, nitrite, nitrate, and N2 [mg N/l] inorganic phosphorus [mg P/l], heterotrophic MO [mg COD/l],
 autotrophic MO (Nitrosomonas andNitrobacter) [mg COD/l], Organic N and P are modelled as N and P
content of the COD.

 hydrolysis (slowly Î readily
biodegradable)

28.03.2008

Ncomponents
processes \ units

2
CR
gCOD

 anoxic growth of heterotrphic
MO using nitrate and nitrite(denitrification)

3
CS
gCOD

4
5
6
7
CI
XH XANs XANb
gCOD gCOD gCOD gCOD

8
NH4N
gN

9
NO2N
gN

Heterotrophic
organisms
The multi-component
reactive transport module CW2D
1-f Hyd,CI

1 hydrolysis
aerobic growth of
2 heterotrophs on readily
biodegradable COD

1 - 1/YH

NO3-growth of
3 heterotrophs on readily
biodegradable COD aerobic growth of heterotrphic
MO (degradation of OM)

ν1,N

fHyd,CI

-1

-1/YH

1

ν2,N

-1/YH

1

ν3,N

1

ν4,N

-1

ν5,N

NO2-growth of
4 heterotrophs on readily
biodegradable COD-1/YH

5 lysisf BM,CR

1-f BM,CR-f BM,CI

fBM,CI

10
11
12
NO3N
N2N
IP
gN
gN
gP
University of Natural Resources andApplied Life Sciences, Vienna
ν1,PDepartment of
Water, Atmosphere, and Environment
ν2,P-(1-YH)/2.86YH (1-YH)/2.86YH

ν3,P(1-YH)/1.71YH

ν4,P-(1-YH)/1.71YH

ν5,P

Nitrosomonas
6

aerobic growth ofN.somonas on NH4

 aerobic growth of Nitrosomonas
and Nitrobacter (nitrification)

7 lysis of N.somonas

 lysis (for heterotrophic andautotrophic MO)

8

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

1
O2
gO2

Simulation of Constructed Wetlands-(3.43-YANs)/YANs
f BM,CR

1-f BM,CR-f BM,CI

fBM,CIf BM,CR

1-f BM,CR-f BM,CI

fBM,CI1

iN,BM-1/YANs

-1

ν7,N

ν6,P

1/YANs

ν7,P

Nitrobacteraerobic growth ofN.bacter on NO2-(1.14-YANb)/YANb

9 lysis of N.bacter

17

1

ν8,N

-1

ν9,N

-1/YANb

1/YANb

ν9,PInstitute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

28.03.2008

ν8,P

18

CW2D reaction rates

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

HF constructed wetland (Spain) – Tracer experiments

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Constant flow rate
Artificial wastewater
Different plant species

Concentration Br- (mg/L)

12

10

Cexp
DPF
DTGD
HYDRUS-2D

8

6

4

2

0
0

5

10

15

Time (d)28.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

1928.03.2008

20

25

30

Comparison of experimental tracer concentrations
to simulation results for CW1 (planted withPhragmites australis) using different models(according to Mena, 2008).

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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5

Simulation Results

Simulation Results

HF constructed wetland (comparison with literature data)
Headley et al. (2005): Treatment at different depths and vertical mixing within a
1-m deep horizontal subsurface-flow wetland. Ecol Eng 25, 567–582.

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

HF constructed wetland (comparison with literature data)

Z

X

Z

X

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

28.03.2008

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Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

HF constructed wetland (comparison with literature data)
250

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

HF constructed wetland (comparison with literature data)
40

35

BottomMiddle

200

Top

30

NH4-N (mg/L)

COD (mg/L)

In/out sim
Headley - middle

150

Headley - top
Headley - bottom

100

25

20

BottomMiddle15TopIn/out sim

10

Headley - middle

50

Headley - top

5

0

1

2

3

4

0

5

Distance from the inlet (m)28.03.2008

Headley - bottom

00Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

1

2

3

4

5

Distance from the inlet (m)2328.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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6

Simulation Results

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

HF constructed wetland (comparison with literature data)
14

Pilot-scale subsurface VF CW for wastewater treatment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

BottomMiddle12TopHeadley - middle
Headley - top
8

6

60

Headley - bottom

main layer

15 10

NO3-N (mg/L)

INLET

In/out sim

10intermediate layer

42

OUTLETdrainage layer

0
0

1

2

3

4

5

Distance from the inlet (m)Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results

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Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Pilot-scale subsurface VF CW for wastewater treatment

Pilot-scale subsurface VF CW for wastewater treatment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Flow simulations

Materials:
Materials:
main layer (0/4mm)
gravelMaterials 4/8mm
gravel 4/8m m
intermediatesand 0/4mm layer (4/8mm)

Z

Y

28.03.2008Xs and 0/4m m

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber2728.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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7

Simulation Results

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Pilot-scale subsurface VF CW for wastewater treatment
Flow simulations

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Pilot-scale subsurface VF CW for wastewater treatment
Flow simulations

60
30%

Measured data
Measured ks + porosity

30%
simulated (2cm)

0-10cm25%

simulated (20cm)

20-30cm25%

simulated (5cm)

simulated (25cm)

40

30

20%

water content

simulated (10cm)

Langergraber (2003)

water content

Effluent rate (ml/min)50

measured (0-10cm)

15%
10%
5%

simulated (30cm)

20%

measured (20-30cm)

15%
10%
5%

20
0%

0%

0

1

2

3

4

5

6

0

1

time after feeding [h]

10

2

3

4

5

6

time after feeding [h]

0
0

1

2

3

4

5

6

Time (hours)
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results

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Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Pilot-scale subsurface VF CW for wastewater treatment
Single-solute transport simulations

Pilot-scale subsurface VF CW for wastewater treatment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Reactive transport simulations

Electrical conductivity (mS/cm)

840 litre/day (measured)

7

40 litre/day (simulated)
60 litre/day (measured)

6

60 litre/day (simulated)
5
4
3
2
1
0
0

1

2

3

4

5

Time after start of tracer experiment (days)
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8

Simulation Results
Pilot-scale subsurface VF CW for wastewater treatment

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Microbial biomass

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Pilot-scale subsurface VF CW for wastewater treatment
Microbial biomass

 CW2D is based on mass balances for COD Î also biomass concentrations are
expressed in terms of COD

Microbial biomass COD (mg/gDW)

7'000

 A number of methods exist to determine the COD of the microbial biomass in activatedsludge systems, however, no method exists for determining the COD of soil biomass.
 Measurements of the C and N content of the biomass and calculate the biomass COD
using conversion factors based on stoichiometry.
 A number of methods have been applied (Tietz et al., 2007), e.g. conversion ofbacterial abundance determined by microscopic direct counts into biomass bymeasurement of the cell volume, fumigation-extraction for biomass-C and -N, ATPmeasurements for biomass-C, and substrate induced respiration (SIR) for biomass-C.

6'000
Calculated from biomass C (SIR)
5'000
Simulated
4'000
3'000
2'000
1'000
0
0

5

10

15

20

25

30

Filter depth (cm)Langergraber (2007): Comparison of measured and simulated distribution of microbial biomass in subsurface vertical flow CWs. Wat.Sci.Technol., (acctepted).
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results
Pilot-scale subsurface VF CW for wastewater treatment

Langergraber (2007): Comparison of measured and simulated distribution of microbial biomass in subsurface vertical flow CWs. Wat.Sci.Technol., (acctepted).
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

28.03.2008

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Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Two-stage subsurface flow constructed wetland

Sensitivity analysis

45
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CHAMBER B
UPFLOW

geotextile

25

x A-1
x A-2
x A-3
x A-4

B-3 x

x A-5

B-2 x

x A-6

B-1 x

CHAMBER ADOWNFLOW

50

sand - gravel 0/4 mm

drainage layer - gravel 16/32 m m

CHAMBER ADOWNFLOW35

OUTLET

70
65
57.5
50
35
20

sand - gravel 0/4 mm

Δ10

25

45

55

15

INLET

top layer - gravel 4/8 mm

15

3Parameters
kaer,O2 ρ Θs α n KS YH bH Kh KX
DispL YANs YANb μH μDN bANs bAnb
Khet,CR KDN,CR fBM,CI
medium Θr μANs Khet,O2 KDN,O2 KDN,NO3N KANs,O2
KANs,NH4N fBM,CR iN,CR iN,BM
μAnb Khet,NH4N KDN,NO2N KDN,NH4N KANs,IP
KANb,O2 KANb,NO2N iN,CS iP,CR DO2,aq DO2,g
weak
DispT Khet,IP KDN,IP KANb,NH4N KANb,IP
iN,CI iP,CS iP,CI iP,BM Dorg,aq DIN,aq DIP,aq

20
35

Influence1strong2

CHAMBER B
UPFLOW

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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9

Simulation Results

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Two-stage subsurface flow constructed wetland

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Two-stage subsurface flow constructed wetland
1630

Top of the main layer

6
5
NH4N measured

20

Simulated conductivity(mobile/immobile water)

15

5

30

40

50

60

4

6

8

20

30

40

50

60

4

0

70

6

Simulated conductivity(only mobile water)

5

Simulated conductivity(mobile/immobile water)

4

Measured conductivity

70

2

37

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Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

10

12

14

16

18

20

effluent

7
6

Simulated conductivity(mobile/immobile water)

5

Measured conductivity

4
3
2

0
2

4

6

8

10

12

14

16

18

20

0

2

4

6

8

10

12

14

16

18

20

time [h]Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

38

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Outdoor CW (Ernsthofen, NÖ) for treatment of wastewater

Langergraber (2007): SciTotEnv., doi:10.1016/j.scitotenv.2006.10.030
28.03.2008

8

1

0

Simulation Results
Two-stage subsurface flow constructed wetland

6

Simulated conductivity(only mobile water)time [h]Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

4

time [h]3028.03.20082

8

B - 3 (50cm)

1

10

Measured conductivity

6

10

7

Vertical flow distance (cm)

0

8

0
2

8

0
20

Simulated conductivity(mobile/immobile water)time [h]110Simulated conductivity(only mobile water)

10

2

0

NO3N simulated

0

12

0

NH4N simulated

2

Measured conductivity

10

NO3N measured

3

Simulated conductivity(only mobile water)

conductivity [mS/cm]

4

conductivity [mS/cm]

NH4N, NO3N (mg/l)

7

A - 6 (20cm)

14

25

conductivity [mS/cm]

conductivity [mS/cm]

A - 4 (50cm)

8

39

28.03.2008

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

3 parallel beds
surface area 20 m² eachorganic loading of 20, 27, 40 g COD/(m².d)Î resp. 4, 3, 2 m²/PE

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

40

10

Simulation Results

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Outdoor CW (Ernsthofen, NÖ) for treatment of wastewater1000

Measured effluent flow
Simulated effluent flow
Measured cumulative effluent
Simulated cumulative effluent

800

60

600

40

400

20

200

0

0

NH4-N simulated

CSB, NH4-N (mg/l)

Effluent flow (L/h)

70
60

80

Cumulative effluent (L)100

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Outdoor CW (Ernsthofen, NÖ) for treatment of wastewater

50

COD simulated
NH4-N measured

40

COD measured

30
20
10
0
0

0

6

12

Time (h)18Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results
CW for treatment of combined sewer overflow

10

15

20

After adaptation of temperature dependencies for KANs,NH4 and KX

Langergraber (2007): SciTotEnv., doi:10.1016/j.scitotenv.2006.10.030
28.03.2008

5Temperature (°C)

2428.03.2008

Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

42

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

CW for treatment of combined sewer overflow

Characteristics
 loading is stochastic and not regularly Î long dry periods
 different composition of CSO compared to wastewater
ColumnDrainage
Filtration rate (m/h)
Effluent flow (litre/h)Treatment goals
 detention and reduction of peak flows (throttles)
 reduction of suspended solids
 reduction of soluble and particulate pollutants by adsorption and biologicaldegradation
HYDRUS-2D/CW2D had to be modified to model a throttled effluent (constant filter velocity) and impoundage (storage volume)
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

C 3/4
throttled
0.180
5

C 5/6
free
-

Lab-scale filter column

Dittmer, U., Meyer, D., Langergraber, G. (2005): Simulation of a Subsurface Vertical Flow CW for CSO Treatment. Wat.Sci.Technol. 51(9), 225-232.
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C 1/2
throttled
0.036
1

Dittmer, U., Meyer, D., Langergraber, G. (2005): Simulation of a Subsurface Vertical Flow CW for CSO Treatment. Wat.Sci.Technol. 51(9), 225-232.
43

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Simulation Results

Simulation Results
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

CW for treatment of combined sewer overflow

CW for treatment of combined sewer overflow

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Dittmer, U., Meyer, D., Langergraber, G. (2005): Simulation of a Subsurface Vertical Flow CW for CSO Treatment. Wat.Sci.Technol. 51(9), 225-232.
Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

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Simulation Results
0

Flow

25

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

20

0.02

15

0.03

10

0.04

5

0.05

0
15

20

25

30

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University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

9 investigation of plant uptake models,
9 numerical simulations of outdoor constructed wetland systems,
 detailed hydraulic investigations of full-scale constructed wetlands,
 development of experimental techniques for the measurement of the CW2D model
parameters, and improving the simulation tool by including a model that is able to describe substrate
clogging processes.

0.06
10

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Research needs

0.01

Total COD

outflow qdr [l/(m²*s)]

effluent concentration [mg/l]30

5Institute of Sanitary Engineering and Water Pollution Control I Günter Langergraber

Simulation of SSFCWs for WWT

CW for treatment of combined sewer overflow

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time [h]O2CSB
NH4-N measured
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CR
NH4N
qdr

CS
NO3N

CI
COD measured

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Simulation of SSF CWs

Simulation of SSF CWs
University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

Summary and Conclusions

Summary and Conclusions

 overview of applications of the multi-component reactive transport module CW2D for
HYDRUS (Langergraber and Šimůnek, 2005).
- different types of CWs have been simulated: VF and HF beds, hybrid systems
and a two-stage down- and upflow CWs- CWs for different applications have been simulated : treatment of municipal
wastewater, polishing the effluent of a wastewater treatment plant for reuse
purposes and treatment of combined sewer overflow.
- CWs with different sizes from lab-scale columns over pilot-scale systems tobigger outdoor systems have been simulated.

 In general, results using CW2D showed that water flow, single-solute transport andreactive transport simulations resulted in good agreements with measured data.
 The practical applications have shown that simulation results match the measured
data when the hydraulic behavior of the system can be described well. A good
match of experimental data to reactive transport simulations can then be obtained for
CWs treating municipal wastewater using the values for the CW2D model parameters
as given by Langergraber and Šimůnek (2005).
 Therefore it is advisable to measure at least the porosity and saturated hydraulicconductivity of the filter material to obtain reasonable simulation results for water flow
(Langergraber, 2008).

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Contact

Announcement
2-day workshop on CW modelling @ IOBB2008

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

CW2D
Modelling Software for Subsurface Flow CWs

Dr. Guenter Langergraber

University of Natural Resources andApplied Life Sciences, Vienna
Department of
Water, Atmosphere, and Environment

University of Natural Resources and Applied Life Sciences, Vienna (BOKU)
Department of Water, Atmosphere and Environment
Institute of Sanitary Engineering and Water Pollution Control

Instructor: Dr Guenter Langergraber,
University of Natural Resources and Applied Life Sciences, Vienna (BOKU).

Muthgasse 18, A-1190 Vienna, Austria
Tel.: +43 (0)1 36006-5814, Fax: +43 (0)1 368 99 49
Email: guenter.langergraber@boku.ac.at
http://www.wau.boku.ac.at/sig.html

Date & location
10&11 July 2008
Murdoch University
Perth, Western Australia
Information: http://www.etc.murdoch.edu.au/IOBB2008/workshop.html
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