Extensions of the Benchmark Simulation Model no2 with ... · DTU Chemical Engineering, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header

Extensions of the Benchmark Simulation Model no2 with processes for nitrous oxide and side-stream partial nitritation/Anammox treatment CAPEC-PROCESS Research Center Riccardo Boiocchi Krist V. Gernaey Gürkan Sin

DTU Chemical Engineering, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header & Footer”

Outline •  Extension of the BSM2 with N2O production processes (the BSM2N)

•  Extension of the BSM2N with PN/A reactor (the BSM2NplusCANR)

•  Uncertainty analysis of BSM2N predictions

•  Sensitivity analysis of BSM2N predictions

•  Comparison between the BSM2N and the BSM2NplusCANR

•  Conclusions

•  Future perspectives

2 21 July 2015 Add Presentation Title in Footer via ”Insert”; ”Header & Footer”


Introduction

3 21 July 2015

BENCHMARKING OF CONTROL STRATEGIES FOR HIGH EFFLUENT QUALITY, ENERGY SAVINGS,……

Not for BENCHMARKING OF CONTROL STRAGIES FOR N2O emission MINIMIZATION and ENHANCEMENT SIDE-STREAM N REMOVAL

ASM1

Inclusion of N2O production and stripping processes

2 EXTENSIONS:

Inclusion of a PN/A reactor in the side stream


Extension of the Benchmark Simulation Model No2 with N2O dynamics- the BSM2N

4 21 July 2015

Activated Sludge Model for Greenhouse Gases no1 (ASMG1) by Guo and Vanrolleghem (2013)

N2O PRODUCTION PROCESSES (a) AUTOTROPHIC DENITRIFICATION

(b) HETEROTROPHIC DENITRIFICATION

N2O STRIPPING

ASM-to-ADM interface updated to include NO2

-, NO and N2O into the pool of electron acceptors used for organic carbon oxidation

Benchmark Simulation Model no2 for Nitrous oxide (BSM2N)


Extensions of the Benchmark Simulation Model No2 with side-stream N removal - the BSM2NplusCANR

5 21 July 2015

Complete Autotrophic Nitrogen Removal model (CANRM)

ü AOB

x  NOB

ü AnAOB ~ HB

by Vangsgaard et al. (2012)

NEW ASM- t o -CANRM INTERFACES developed

IMPLEMENTED AT THE BOTTOM OF THE DEWATERING UNIT of BSM2N

The Benchmark Simulation Model no2 for Nitrous oxide and Complete Autotrophic Nitrogen Removal (the BSM2NplusCANR)


Steady state predictions by BSM2N

6 21 July 2015

41.22%

13.4%

45.4%

0.01% 0.02%

41.19% NO N2O N2

TNIN TNeff

TNsludge

HOW THE UNCERTAINTY IN MODEL PARAMETERS AFFECT

THE PREDICTIONS?

ASMG1

UNCERTAINTY AND SENSITIVITY ANALYSES

19.5%

23.2%

0.13%

1.7%

0.9%

NO3-

N2

NORG

NPART,INORG

NH4+

[O2]AER1,2,3=2 mg.L-1

TNgas


Uncertainty and sensitivity analyses on BSM2N predictions

7 21 July 2015

PERTURBATION OF MODEL PARAMETERS

5% variation on GROWTH YIELDS

25% variation on GROWTH/DECAY RATES, N CONTENTS

50% variation on INHIBITION AND HALF-SATURATION PARAMETERS 100% variation on INHIBITION AND HALF-SATURATION PARAMETERS OF AOB-MEDIATED N2O-PRODUCTION PROCESSES STEADY-STATE SIMULATIONS OF THE BSM2N

[O2]AER1,2,3=2 mg.L-1

[TSS]AER3=4000 mg.L-1

PREDICTED TN FLUXES PREDICTED O2 CONSUMPTIONS

Effect on:

PREDICTED N2O EMISSIONS

+SEASONAL

EFFECT on N2O

T=12oC T=15oC T=20oC


Uncertainty of TN fluxes

8 21 July 2015

units µ σ σ/µ 95th

percentile overall TN stripped [%] 27.09 4.09 0.15 33.8

TN sludge [%] 16.35 2.07 0.13 19.7 TN reject [%] 23.56 2.03 0.09 27

TN removal efficiency [%] 0.64 0.05 0.07 0.7 NO3

- effluent [g.m-3] 16.06 2.07 0.13 19.3 NH4

+ effluent [g.m-3] 0.09 0.05 0.53 0.2

LOW UNCERTAINTY ON TOTAL NITROGEN FLUXES

T=15oC


Uncertainty of O2 consumptions

9 21 July 2015

units µ σ σ/µ 95th prcl specific O2 consumtpion [g O2,cons.g-1 TNrem] 11.65 1.03 0.09 13.4

O2 cons. by HB [kg O2,cons.d-1] 2847 225.4 0.08 3189 O2 cons. by AOB [kg O2,cons.d-1] 2974.1 61.1 0.02 3069 O2 cons. by NOB [kg O2,cons.d-1] 1116 116.2 0.10 1314

total O2 consumption [kg O2,cons.d-1] 6937 274 0.04 7419

LOW UNCERTAINTY ON OXYGEN CONSUMPTIONS

T=15oC


Uncertainty of N2O emissions

10 21 July 2015

T=15oC units μ σ σ/μ 95th prct

N2OANOX1 per N2Otot [gN2Otank1.g-‐1N2Otot] 0.05 0.02 0.45 0.09 N2OANOX2 per N2Otot [gN2Otank2. g-‐1N2Otot] 0.05 0.02 0.46 0.09 N2OAER1 per N2Otot [gN2Otank3. g-‐1N2Otot] 0.85 0.05 0.06 0.90 N2OAER2 per N2Otot [gN2Otank4. g-‐1N2Otot] 0.04 0.03 0.67 0.08 N2OAER3 per N2Otot [gN2Otank5. g-‐1N2Otot] 0.01 0.03 2.74 0.01





LOW UNCERTAINTY ON the N2O EMISSION distribution among the AS tanks

STRIPPING

MOST OF N2O IS EMITTED FROM THE FIRST AEROBIC TANK


Effect of temperature on N2O emissions

11 21 July 2015

units µ σ σ/µ 95th prct T=12oC T=15oC T=20oC T=12oC T=15oC T=20oC T=12oC T=15oC T=20oC T=12oC T=15oC T=20oC

N2O AER1 [g N.d-‐1] 719.1 1924.4 1963 2800 11871 12341 3.9 6.17 6.3 1500 1510.8 1437.3

THE UNCERTAINTY OF N2O INCREASES AS TEMPERATURE INCREASES

HIGH UNCERTAINTY IN N2O EMISSIONS

A GENERAL BEHAVIOUR OF N2O EMISSIONS WITH TEMPERATURE VARIATION CAN NOT BE IDENTIFIED


Sensitivity of TN fluxes

12 21 July 2015

Monte Carlo method

nh nY kh

TN effluent -0.56 0.38 -0.25

STANDARDIZED REGRESSION COEFFICIENTS

nh nY fP

TN stripped 0.53 -0.38 -0.32

iXP fP YH

TN sludge 0.83 0.51 0.15

iXB bH YH

TN reject 0.75 -0.49 0.33

hSS,ANOX

hnh

hNOx red. to N gases

hiXP

hsolids in AS unit

hiXB hN released during sludge stabilization

The key strategy to enhance ηTN is to prov ide HB w i th enough SS

hN rem. through sludge disposal

hQwastage

T=15oC

MODEL

LATIN HYPERCUBE SAMPLING PERTURBATION OF PARAMETERS ACCORDING TO

STARDARDIZED REGRESSION COEFFICIENTS


Sensitivity of O2 consumptions

13 21 July 2015

fP bH YH

O2 consumption by HB -0.58 0.55 -0.42

fP iXP iXB

O2 consumption by AOB -0.63 -0.42 0.4

KS2 ng2 KOH2

O2 consumption by NOB -0.42 0.25 0.23

nh nY fP

Tot. O2 consumption per unit of TN removed -0.56 0.3 -0.25

Monte Carlo method

STANDARDIZED REGRESSION COEFFICIENTS #fP

$SS from biomass decay $O2 cons. for SS oxid. by HB

#fP $XND from biomass decay

$SNH to be oxidized by AOB

#KS2

$NO3- to NO2

- reduction

$NO2- to be oxidized by NOB

#nh #SS in anoxic zone

hSS oxidation with NOX rather than with O2

NO3--to-NO2

- reduction is the key process

T=15oC


T=20oC µ(EEi)

KS5 0.39

KS1 -0.27

KOH5 -0.25

ng2 0.17

ng4 -0.13

KNO2 -0.11

T=15oC µ(EE

i)

KS5 0.47

KN2O 0.42

KOH5 -0.34

ng5 -0.28

ng2 0.19

bH,KS3 -0.17

KO2,NOB 0.13

µNOB -0.1

Sensitivity of N2O emissions

14 21 July 2015

MODEL

Perturbation coefficient of the parameters

p is the number of levels of variation of θ

N2O emissions are non-linearizable Total N2O emitted

Monte Carlo method Morris screening method

Elementary effect of parameter θi in a point input-space θr

T=12oC µ(EEi)

µNOB -0.61

KS5 0.42

KN2O 0.41

KOH5 -0.26

KFNA 0.25

KS1 -0.23

KS3 -0.2

KNO2 -0.17

ng2 0.14

KS4 0.13

ng5 -0.13 HB denitritifcation plays a dominant role in determining N2O emissions at T=15oC and 20oC

EMERGING CONTRIBUTION BY NOB ACTIVITY ON N2O EMISSION FOR DECREASING TEMPERATURES


Steady state predictions by BSM2NplusCANR

15 21 July 2015

PN/A

35.5%

[O2]AER1,2,3=2 mg.L-1

13.4%

16.8%

34.3%

19.5%

12%

0.16%

1.7%

0.9%

NO3-

N2

NORG

NPART,INORG

NH4+

0.004% 0.01%

35.49% NO N2O N2

0.02% 41.22%

!N2O/TNstripped

due to lower stripping

23.2%

!NO3-

due to lower infl. NH4

+ load in AS unit


Conclusions •  novel benchmark simulation models for developement of control strategies for

N2O emissions (BSM2N) and for enhanced TN removal (BSM2NplusCANR) have been built up

16 21 July 2015

•  Uncertainty analysis show low uncertainty in the TN fluxes predictions but high uncertainty in N2O emissions

•  Sensitivity analysis indicates nh and nY as the most influencing parameters determining the plant TN removal efficiency

•  The most influencing parameter on N2O emissions at T=15oC and 20oC is the SS half saturation parameter for N2O-to-N2 reduction by HB (KS5)

•  Winter temperatures lead to emerging contribution by NOB activity on N2O emissions

•  The implementation of the PN/A reactor leads to a reduction of N2O emitted per unit of TN stripped from the AS unit and to a drastic reduction of NO3

- in the effluent


Future perspectives

•  Performing uncertainty and sensitivity analyses on BSM2NplusCANR predictions

17 21 July 2015

•  Including N2O production and emission processes in the side-stream PN/A reactor of BSM2NplusCANR

•  Developing control strategies for minimization of N2O emission from both mainstream and side-stream biological treatments

•  Validate the control strategy obtained in a real full-scale plant


THANK YOU FOR THE ATTENTION

18 21 July 2015


TN fluxes predicted by BSM2N vs BSM2NplusCANR

19 21 July 2015

TN stripped from AS 41.22 % 35.5% TN effluent 45.4 % 34.4% TN sludge 13.4 13.4

TN stripped from PN/A 0 16,8%

10 % MORE TN REMOVED BY INCLUSION OF CANR

TN removed 54.6 % 65.7 %

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Extensions of the Benchmark Simulation Model no2 with ... · DTU Chemical Engineering, Technical University of Denmark Add Presentation Title in Footer via ”Insert”; ”Header