Università degli Studi di SalernoDipartimento di Ingegneria CivileDipartimento di Ingegneria Civile
Laurea in Ingegneria per l’Ambiente ed il Laurea in Ingegneria per l’Ambiente ed il Territorio in Territorio in Impianti di trattamento delle acque reflue IIImpianti di trattamento delle acque reflue II
ENHANCED BIOLOGICAL PHOSPHORUS ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL BY ANAEROBIC, AEROBIC/ANOXIC REMOVAL BY ANAEROBIC, AEROBIC/ANOXIC
PROCESSESPROCESSES
AllievoAllievoPaolo SianoPaolo SianoN.Mat. 06205-N.Mat. 06205-000160000160
Relatore:Relatore:Prof.Ing. Luigi RizzoProf.Ing. Luigi Rizzo
Correlatore:Correlatore:Prof.ssa. Maria Ascensão ReisProf.ssa. Maria Ascensão Reis
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : 29 April 2011
FrameworkFramework
Background Objectives Materials and methods
Wastewater sampling
Batch test
Chemical Analysis
ResultsPhosphorus in Beirolas WWTP
Anaerobic-Aerobic and Anaerobic/Anoxic batch tests
Conclusions
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : 29 April 2011
BackgroundBackground
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : 29 April 2011
World Resource institute (www.wri.org)
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : 29 April 2011
World Resource institute (www.wri.org)
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : 29 April 2011
Parameter Power plant in terms of population equivalent
D.E. 91/271/CEE
10,000 – 100,000 >100,000
Concentrazione
% di riduzione
Concentr. % di riduz.
Total P (P mg/l) ≤ 2 80 ≤ 1 80
Total N (N mg/l) ≤ 15 70-80 ≤ 10 70-80World Resource institute (www.wri.org)
Chemical Chemical RemovalRemovalChemical Chemical RemovalRemoval
Biological Biological RemovalRemoval
(EBPR)(EBPR)
Biological Biological RemovalRemoval
(EBPR)(EBPR)
PRECIPITATIONPRECIPITATION
ADDITION OF METAL SALTS
ENHANCEENHANCE
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ANAEROBIC/AEROBIC
PROCESSES
promoted byPoliphosphate Accumulating
Organisms(PAOs)
Much lower operating costs Reduced sludge production Reuse processed sludge
Phoredox [A/O]Phoredox [A/O]
ANAEROBIC CONDITIONSliquid phase
energy
O2
liquid phase
O2
AEROBIC CONDITIONS
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
energy
liquid phase
NO2
NO3
Phoredox 3-stage [A2/O]
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
energy
O2
University of Cape Town (UCT)
Bardenpho
Combined nitrogen and phosphorus removal schemes
Virginia Initiative Plant [VIP]
A2/O
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
BackgroundBackground
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Carvalho et. al. (2007) observed
difference in anoxic P-uptake and
proposed hypothesis that different
Accumulibacter clades have
different metabolic capabilities.
***
Flowers et al., (2009) confirmed
that two different clades have
affinities to nitrate: type I
Accumulibacter, hereafter refered
as PAOI, seems having the ability
to denitrify using nitrate, contrary
to Type II Accumulibacter,
hereafter PAOII. Although anoxic
conditions with nitrate seems to
favor PAOI over PAOII, they seem
be able to co-exist.
The aim of the study has been the optimization of the Enhanced Biological Phosphorus Removal
(EBPR) through:
ObjectivesObjectives
Reproduction of the EBPR
process at lab-scale and
evaluation process
efficiency;
Estimation of the
microbial composition of
Beirolas UWWTP through
chemical analysis,
according to the method
proposed by Meinhold et
al. (1999).
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ExperimentalExperimental
Materials and methods: wastewater Materials and methods: wastewater samplingsamplingActivated sludge was collected from
Beirolas UWWTP (Loures, Portugal)
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Beirolas UWWTP
Materials and methods: wastewater Materials and methods: wastewater samplingsampling"Barden-pho" BPR unit configuration based on 3-
stages
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
• Anaerobic zone
(4.3% of total);• Anoxic zone
(21.3% of total);
• Aerobic zone(74.4% volume total).
Materials and methods: wastewater Materials and methods: wastewater samplingsampling
5 L 5 L of sludge from aerobic tank of sludge from aerobic tank to arrange biological batch tests.to arrange biological batch tests.
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Materials and methods: wastewater Materials and methods: wastewater samplingsamplingAdditional samples from :Additional samples from : biological unitsbiological units (Anaerobic, anoxic and (Anaerobic, anoxic and aerobic tank);aerobic tank); primary and secondary settling. primary and secondary settling.
In order to characterize the plant.In order to characterize the plant.
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Materials and methods: batch testMaterials and methods: batch test
Batch test conditionsBatch test conditionsAcetate as carbon source
Temperature of 22°C (±2°C)
pH in the range 6.5÷7.5
ANAEROBICANAEROBICREACTORREACTOR
AEROBIC AEROBIC REACTORREACTOR
ANOXIC ANOXIC REACTOREACTO
RR
Volume 1.5 L
Volume 0.6 L
Volume 0.6 L
SPLITSPLIT
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Chemical AnalysisChemical Analysis
Phosphorus, Acetate, Nitrate Phosphorus, Acetate, Nitrate Hight Pressure Liquid Chromatography Hight Pressure Liquid Chromatography
(HPLC)(HPLC)IonPac® AS9-HCIonPac® AS9-HC
PhosporusPhosporusAscorbic acid methodAscorbic acid methodSkalar 5100Skalar 5100
AmmoniaAmmoniaAmmonia gas sensing combination electrode Ammonia gas sensing combination electrode Thermo Orion, NH4/95-12Thermo Orion, NH4/95-12
Total and Volatile Suspended Total and Volatile Suspended Solids Solids (TSS, VSS)(TSS, VSS)
Membrane Filtration MethodMembrane Filtration Method
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ANAEROBIC ANAEROBIC REACTORREACTOR
Time (min)Time (min)
Conc
. of P
Conc
. of P
~ ~ 120120 ~ ~ 360360
Max release of PMax release of P
anaer.anaer. aer./anox.aer./anox.
Carbon comsuptionCarbon comsuption
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
AEROBIC REACTORAEROBIC REACTORMax release of PMax release of P
Max aerobic Max aerobic uptake of Puptake of P
Time (min)Time (min)
Conc
. of P
Conc
. of P
anaer.anaer.
~ ~ 120120 ~ ~ 360360
aer./anox.aer./anox.
Carbon comsuptionCarbon comsuption
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ANOXIC REACTORANOXIC REACTORMax release of PMax release of P
Max anoxic Max anoxic uptake of Puptake of P
Time (min)Time (min)
Conc
. of P
Conc
. of P
~ ~ 120120 ~ ~ 360360
anaer.anaer. aer./anox.aer./anox.
Carbon comsuptionCarbon comsuptionNitrate Nitrate
comsuptioncomsuption
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
Batch test for B4 samples. Initial Acetate concentration 25 ppm; Initial concentration of P 20ppm; Initial NO3 25ppm.
Anaerobic condition
Aerobic/Anoxic
condition
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
Batch test for B6 samples.Initial Acetate concentration 30 ppm; Initial concentration of P 20ppm; Initial NO3 25ppm.
Anaerobic condition
Aerobic/Anoxic
condition
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
Batch test for B7 samples. Initial Acetate concentration 40 ppm; Initial concentration of P 20ppm; Initial NO3 25ppm.
Spiking of P
Anaerobic condition
Aerobic/Anoxic
condition
Aerobic condition
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
Batch test for B8 samples.Initial Acetate concentration 40 ppm; Initial concentration of P 20ppm; Initial NO3 25ppm.
Anaerobic condition
Aerobic/Anoxic
condition
P Ae (on Ax)
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
Batch test for B5 samples.Initial Acetate concentration 50 ppm; Initial concentration of P 20ppm; Initial NO3 25ppm.
Anaerobic condition
Anoxiccondition
Aerobic condition
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Anaerobic-Aerobic and Anaerobic-Aerobic and Anaerobic/Anoxic batch testsAnaerobic/Anoxic batch tests
n° Batch
Initial
Hac
P-release rate
An. P/HAc ratio
Ae P-uptake
rate
Ax. P-uptake
rate
Ax/Ae P uptake
rate
[-] [mg/L][mgP/gVSS/
h][molP/
molHAc][mgP/gVSS/
h][mgP/gVSS/h] [%]
B4 25 9.73 0.37 7.40 3.68 36.45
B6 30 11.63 0.19 3.87 1.50 28.44
B7 40 6.68 0.18 8.57 3.55 45.34
B8 40 9.98 0.22 6.51 1.88 49.40
B5 50 8.61 0.22 n.r. n.r. n.r.avarage
>>9.33 0.23 6.59 2.65 39.91
stand.dev.>>
1.83 0.08 2.00 1.12 9.36
Summary of the anaerobic-aerobic-anoxic activity batch tests results carried out
According to other studies
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: Assessing PAO/DPAO activityAssessing PAO/DPAO activity
Time (min)Time (min)
Conc
. of P
Conc
. of P
~ ~ 120120 ~ ~ 360360
anaer.anaer. aer./anox.aer./anox.
Anoxic Anoxic uptakeuptake
Aerobic Aerobic uptakeuptake Anaerobic releaseAnaerobic release
Aerobic uptakeAerobic uptakeAnoxic uptakeAnoxic uptakeAcetate consuptionAcetate consuptionNitrate consuptionNitrate consuption
XDPAO
XPAO
DPax
DPox =
Relative activity of DPAO
in EBPR systems(Meinhold et al.,1999)
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
XDPAO
XPAO
DPax
DPox =
Relative activity of DPAO
in EBPR systems(Meinhold et al.,1999)
Results: Results: Assessing PAO/DPAO activityAssessing PAO/DPAO activity
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: phosphorus in Beirolas WWTPResults: phosphorus in Beirolas WWTP
Efficiency
92%
?“secondary”
P-release
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
Results: Results: WWTP & Batch testsWWTP & Batch tests
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ConclusionsConclusions
EBPR process at lab-scale was reproduced and typical trends of phosphorus, nitrate and acetate were observed;
The batch tests results obtained suggest that phosphorus removal is due to two type of PAOs: PAOs type I (also called DPAOs) that are likely to be able to reduce nitrate and PAO type II that cannot;
Relative chemical activity of PAOs and DPAOs was estimated, (Meinhold et al. 1999): DPAOs occurrence as high as 40% and PAOs occurrence as high as 60%;
Phosphorus removal efficiency at Beirolas UWWTP is quite variable, but under the investigated conditions a 92% removal was observed;
The higher the concentration of intracellular phosphorous in aerobic tank of UWWTP the higher the phosphorus release rate in the anaerobic phase of batch test.
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011
ConclusionsConclusions
The knowledge of the microbial composition and its efficiency
is key factor to perform good P and N removals.
: : Enhanced Biological Phosphorus Removal by anaerobic, aerobic/anoxic processes : : Presented on the 29 April 2011