A Benchmark Simulation Model to
describe plant-wide phosphorus
transformations in WWTPs
Dr Ulf Jeppsson
Div. of Industrial Electrical Engineering and Automation (IEA)
Lund University, Sweden
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Acknowledgements
Industrial Electrical Engineering and Automation
To all co-authors:
–  Dr Xavier Flores-Alsina, Technical University of Denmark
–  Dr David Ikumi, Univ. of Cape Town, South Africa
–  Christian Kazadi-Mbamba, Univ. of Queensland, Australia
–  Kimberly Solon, Lund University, Sweden
–  Dr Stephan Tait, University of Queensland, Australia
–  Chris Brouckaert, Univ. of KwaZulu-Natal, South Africa
–  Dr George Ekama, Univ. of Cape Town, South Africa
–  Dr Damien Batstone, University of Queensland, Australia
–  Dr Krist Gernaey, Technical University of Denmark
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Outline
§  Introduction
§  Methodology
§  New and upgraded models
§  Model integration
§  Additional BSM modifications
§ 
§ 
§ 
§ 
Results
Discussion
Conclusions
Perspectives
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Introduction
§  BSM work started as part of an EU COST action in 1997
§  IWA Task Group on Benchmarking of Control Strategies
for WWTPs initiated in 2005
§  Today finalized versions of BSM1, BSM1_LT, BSM2, the
influent wastewater generator model, ADM1 with PCM
and more – available for free
§  IWA Scientific & Technical Report no. 23 (2014)
§  500+ publications related to BSM
§  Many ongoing BSM extension (GHG, P, S, X, PCM etc)
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Benchmark Simulation Models
BSM1
BSM1_LT
BSM2-P
BSM2
Schematic representation of the BSM2 plant (Gernaey et al., 2014).
Effluent Quality Index
Operational Cost Index
Risk Index
C, N removal
C, N, P removal
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
New/upgraded bio(chemical) models
Industrial Electrical Engineering and Automation
Activated Sludge Model No. 2d (ASM2d)
§  biomass decay rate are electron-acceptor
dependent
§  inorganic suspended solids added (XTSS)
§  chemical precipitation replaced
Physico-chemical Model (PCM)
§  pH model (Batstone et al., 2012;
Flores-Alsina et al., 2015))
§  ion speciation/pairing model (Solon
et al., 2015)
§  precipitation model (KazadiMbamba et al., 2014)
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
Anaerobic Digestion Model No. 1 (ADM1)
§  with bio-P (Ikumi et al., 2014)
§  XC is omitted –> towards ADM2
§  hydrolysis parameters are adjusted
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Model integration
Industrial Electrical Engineering and Automation
Activated Sludge Model No. 2d (ASM2d)
ASM – ADM
interface
ASM – PCM
interface
Physico-chemical Model (PCM)
ADM – PCM
interface
Anaerobic Digestion Model No. 1 (ADM1)
using continuity-based interfacing models (Vanrolleghem et al., 2005)
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Influent Generator
15
14
13
12
4
-3
11
PO
Industrial Electrical Engineering and Automation
New influent characteristics
10
9
8
7
6
5
0
1
2
3
4
t (days)
also reasonable dynamics of all anions and cations included
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
5
6
7
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
New BSM2-P plant layout
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
New/extended evaluation criteria
EQI
Effluent Quality Index
§  include phosphorus-related compounds
OCI
Operational Cost Index
§  account for use of chemicals and their
impact on sludge production
§  benefit of nutrient recovery (e.g.
struvite)
Risk Index
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
§  include P, S, pH - related issues (not done)
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Results
12
10
8
8
6
g m-3
10
TKN
SNO3
TKN
SNO3
TN
TN
NO3
NO3
6
4
4
2
2
0
0
0
0
20
5
5
4
4
g m-3
14
12
g m-3
14
g m-3
scenario 1
scenario 1
addition of Mg
3
2
1
20
40
40
60
60
80
80
100
100
120
0
120
TP
SIP
3
2
1
0
0
10
8
8
6
4
20
0
5
4
4
3
2
1
2
0
0.2 0 0.4 0.2 0.6 0.4 0.8 0.6 1 0.8 1.2 1 1.4 1.2 1.6 1.4 1.8 1.6 2 1.8
0
2
80
100
100
120
120
2
1
0
0
0.2 0 0.4 0.2 0.6 0.4 0.8 0.6 1 0.8 1.2 1 1.4 1.2 1.6 1.4 1.8 1.6 2 1.8
10
8
8
6
4
4
2
2
0
0
0
10
5
5
4
4
g m-3
10
3
2
1
21
32
43
54
internal recycle
internal recycle
(Q /Q (Q
)
intr
(e)
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
60
80
-1 3
additionaddition
of acetate
of acetate
(m3 day(m
) day-1)
(d)
(d)
g m-3
12
g m-3
14
12
g m-3
scenario 3
14
6
40
60
3
additionaddition
of acetate
of acetate
(m3 day-1
(m) 3 day-1)
(c)
(c)
manipulation of
internal recycle
flow rate
20
40
4
2
0
0
6
5
g m-3
10
IP
additionaddition
of Mg (kg
of day
Mg -1(kg
) day-1)
(b)
(b)
g m-3
12
g m-3
14
12
g m-3
scenario 2
scenario 2
addition of
carbon source
14
TP
SIP
IP
additionaddition
of Mg (kg
of day
Mg -1(kg
) day-1)
(a)
(a)
scenario 3
Industrial Electrical Engineering and Automation
Preliminary results of the BSM2-P prototype (steady state)
r
65
/Q )
intr
r
6
0
3
2
1
0
0
10
21
32
43
54
internal recycle
internal recycle
(Q /Q (Q
)
(e)
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
intr
(f)
(f)
r
65
/Q )
intr
r
6
2
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Discussion
Modelling requirements
to realistically describe P
§ 
§ 
§ 
§ 
Compositional analysis
Weak acid-base chemistry, pH estimation
Numerical issues to solve (for PCM)
Multiple mineral precipitation modelling
Development of control
strategies to recover
N and P
§ 
§ 
§ 
§ 
Plant layout modifications
Nutrient recovery processes
Sulfur and iron interactions
Agreement on evaluation criteria
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Conclusions
Industrial Electrical Engineering and Automation
Simultaneous C, N and P descriptions require
substantial model (ASM, ADM and PCM)
modifications/upgrades
Special attention must be placed on model
interfacing, particularly regarding to ASM-ADMASM and both ASM-ADM with PCM
Plant-wide P removal requires definition of state
variable empirical formulas plus elemental and
COD and charge continuity checking
As far as overall P removal is concerned, metallic
ions and pH in the AD play an important role
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Perspectives
§  BSM2-P free software available this year (Matlab)
§  ADM1 model extended with ion pairing, speciation and
activities available for download
§  Recovery processes should be added to plant layout
§  Processes related to sulfur need to be included
§  More collaboration between groups on plant-wide/
system-wide model development needed
§  Integration of C, N, P, S, X, GHG, PCM, precipitation?
§  Towards BSM3 – catchment, sewer, plant, recipient
§  IWA Working Group a suitable platform for collaboration?
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs
Watermatex2015, June 14-17, Surfers Paradise, Queensland, Australia
Industrial Electrical Engineering and Automation
Thank You for Your Attention!
Questions and comments?
(more BSM info at www.benchmarkwwtp.org)
Financially supported by:
EU projects PROTEUS (329349) and SANITAS (289193)
© Dr Ulf Jeppsson, 2015
Lund University, Sweden
A Benchmark Simulation Model to describe plantwide phosphorus transformations in WWTPs