Post on 17-May-2018
B.X. Thanh
1/40 B.X. Thanh - 10417314-Jan-09
Fin
al P
rese
nta
tion
Fouling Behavior & Nitrogen Removal in The Aerobic Granulation
Membrane Bioreactor
Bui Xuan Thanh
Prof. C. Visvanathan (Chairman)
Asian Institute of TechnologySchool of Environment, Resources & Development
Environmental Engineering & Management
Dr. Esa Viljakainen
Dr. Oleg V. Shipin
Examination Committee:
SBAR
MBR
Dr. Mathieu Spérandio
2/40 B.X. Thanh - 10417314-Jan-09
Answers For Examiner’s Comments
1. Author should give more precision for such a choice of OLR and NLR values. After
the reduction of NLR (but no information to justify this new choice)
- OLR of 2 kgCOD/m3.d is commonly highest designed for the CAS process in reality.
- NLR of 1 kg N/m3.d was the high loading to investigate the maximum SND of BG-MBR
without external C addition.
- NLR, then reduced to 0.5-0.6 N/m3.d to avoid effect of the pH fluctuation.
2. The time of aeration appears sufficient to remove C & ammonia but nitrates never
appeared in opposite with the appearance of nitrites. Discussion about these
phenomena according to size, granule structure and operation time.
- Nitrite-oxidizing bacteria is inhibited (high toxic nitrite) inhibit nitrate formation.
- Microorganisms (heterotrophs, ammonia-oxidizing, nitrite-oxidizing) exist in 200 µm
from surface. Nitrite-oxidizing bacteria is a minor population (Tsunenda et al., 2003).
(a, b) Yellow: ammonia oxidizing bacteria. Red: other bacteria(c) Yellow: nitrite-oxidizing bacteria. Red: other bacteria
3/40 B.X. Thanh - 10417314-Jan-09
Answers For Examiner’s Comments
3. Biomass concentration in SBAR reached 18 gVSS/L (it could be interesting to
differentiate active biomass from volatile biomass compounds
- This method measured volatile biomass (VSS) based on the TOC of mixed sludge
conversion factor (Tijhuis et al., 1994).
- VSS = active biomass + cell debris (biomass decay)
- In CAS, active biomass = 85-90% VSS.
- In granular sludge, it is probably lower (long retention of granule) further study.
4. Discuss the configuration in relation with performances and cost, could such a
system be relevant only with an immersion of membranes in a specific zone of setter.
- This solution could reduce number of unit processes and energy.
- Fouling rate of BG-MABR was found higher than that of BG-MBR (0.105 kPa/d and
0.027 kPa/d) (sludge concentration 2 g/L and 4 g/L for MBR and MABR).
- Specific energy was 0.1, 0.9 & 1.6 kWh/m3 for aerobic reactor, MBR & BG-MBR.
- OLR: MBR (< 8 kgCOD/m3.d) and BG-MBR (up to 15) kgCOD/m3.d.
4/40 B.X. Thanh - 10417314-Jan-09
Answers For Examiner’s Comments
- Proposed system is probably compact & less fouling potential compared to BG-MBR &
MG-MABR.
- Denitrification can be enhanced with a recirculation from membrane chamber to
settling chamber.
MBR chamber
Air supply
Permeate Effluent
SBAR
Setller-combined MBR
Up level
Down level
Sludge withdrawalSettlingchamber
Settler-combined MBR
Recirculation
5/40 B.X. Thanh - 10417314-Jan-09
Answers For Examiner’s Comments
5. To improve nitrogen removal & granular stability coupling to form a BG-MBR. This
combination induced a partial destruction of granules with appearance of fungi,
filaments & decreasing granular bed volume. Author attributes these phenomena to
the difficulty of control of optimal SRT (nevertheless, the quick variation of the
sludge composition did not correspond to the SRT).
- Granules disintegrated after a certain time of operation (about 300 days).
- Granule breakage occurred due to their long retention in SBAR (filaments & fungus).
- In granulation SBAR, the SRT was calculated by the conventional method as:
SRT = Sludge in reactor/sludge wasted out per day
- SRT calculated for granulation reactor is just a relative definition.
- Sludge washed out (< 10 m/h): light fraction (flocs, small granules, detached particles).
Granules retained in reactor
- Actual SRT = 10-15 d to avoid filaments Perform appropriate sludge removal
methods to control actual SRT to enhance granule stability. Periodical sludge
removal (a) mixed sludge; (b) top sludge; and (c) bottom sludge.6/40 B.X. Thanh - 104173
Answers For Examiner’s Comments
6. Result pointed out that the difficulty to achieve adequate nitrogen removal probably
link to the opposite conditions imposed by granulation and anoxic reduction of NOx
when NLR is too high. (A simulation with ASM model could indicate the adequate
time of aeration and non aeration to remove nitrogen and its conformity with
granular bed stability). Author should take some interest to ASM model to identify
the necessary time of aerobic/anoxic periods and the mass transfer through the
granule to remove nitrogen and compare the results to the optimal conditions to
maintain the structures of granule.
- For the proposed objectives, it needs to measure specific kinetic data, mass transfer
constants, mass transfer coefficients and active biomass for granule at various NLR,
OLR which have not planned in this research These objectives to be performed in
the future research.
7. Some corrections in chapter 3 has been corrected in the final version of Dissert.
B.X. Thanh
7/40 B.X. Thanh - 10417314-Jan-09
Background: Aerobic Granule
• Size: 0.5–9.0 mm Simultaneous nitrification/denitrification;
• Excellent settling ability (20-110 m/h, SVI = 18 mL/g)
• Tolerate temperature range (8-55oC) (De Kreuk et al., 2005);
• Microbial diversity;
• Remove phenol (3.8 kg/m3.day) (Tay et al., 2005)
and nitrilotriacetic (NTA) (Nancharaiah et al., 2006)
DO NO3-
CODNH4
+
Granule Bulk liquid
Anaerobic core
Aerobic layer
Carrier
8/40 B.X. Thanh - 10417314-Jan-09
Rationale: Aerobic Granulation MBR
Permeate
SBAR
MBR
AEROBIC GRANULE & MBR?
Aerobic Granule!
+Being popular due to cost reductionWater reuse and recycling; High SRT, MLSS & OLR less footprint;But fouling, sludge treatment, and oxygen transfer.
MBR
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Objectives of Study
1. Study on organic removal and simultaneous nitrification denitrification of aerobic granule and its stability in SBAR;
2. Characterize the fouling behavior of an external submergedMBR treating granulation SBAR effluent (BG-MBR) ;
3. Study on granule stability and fouling propensity of the Continuous Granulation MBR (CG-MBR) at various organic loading rate (OLR);
10/40 B.X. Thanh - 10417314-Jan-09
Overall Experimental Plan
Phase I a (AIT)
Batch granulation MBR(BG-MBR)
Aerobic Granulation MBR
Continuous granulation MBR(CG-MBR)
+ C, N removal+ Granule characterization+ Granule stability+ Fouling behavior
Phase I b (INSA)* Phase II (AIT)
SBAR
+ Effect of aeration rates(conventional vs granulation)
+ Effect of anoxic/aerobiccondition on sludge/effluentof SBAR
+ Granule stability;+ Effect of OLR on fouling,
N removal
*INSA = Institut National des Sciences Appliquées, Toulouse, France
SBAR
Settler
MBR
11/40 B.X. Thanh - 10417314-Jan-09
Batch Granulation MBR (BG-MBR): Phase Ia
Supernatant
SBAR
Cycle (4 hrs) Feeding High Aeration Low Aeration Settling WithdrawalTime (min) 6 198 30 3 3
SBAR:High aeration: 1.7 cm/sLow Aeration: 0.1 cm/sNLR: 0.6-1 kgN/m3.dOLR: 2 kg/m3.dShell carrier
MBR:Air flow: 0.3 cm/sFlux: 2.8 L/m2.hHRT: 3.4 hSRT: 20 dSuction: 7on/3off
MBRHollow fibre, PE
membrane area 0.42 m2
Permeate P
Air supply
12/40 B.X. Thanh - 104173
MBR
Timer
PLC
Level controller
SBAR
Settler
Feed tank
Air flow meter
PG
Suction pump
BG-MBR: Lab Scale Systems
B.X. Thanh
13/40 B.X. Thanh - 10417314-Jan-09
MBR & Measured Parameters
Soluble parameters:• TOC, Nitrogen species• EPS (PS, PN)• UVA254, SUVA (= UVA254/DOC)• Size Exclusion Chromatography (SEC-EEM)• Hydrophobicity
Sludge parameters:• MLVSS/MLSS• SVI• Capillary Suction Time (CST)• Microscopic Observation• Specific oxygen uptake rate (SOUR)
Membrane fouling parameters:• Modified Fouling Index (MFI) (SS, CL, SL)• Trans-membrane pressure (TMP)• Critical flux• Particle Size Distribution (PSD)• Resistance/Resistance rate
Hollow FibreMembrane Module
External Submerged MBR
14/40 B.X. Thanh - 10417314-Jan-09
Effect of Aeration Rates and Anoxic growth on SBAR effluent– Phase I b
Operating conditions:- SBAR: V = 17 L,
H = 1.07 m, D = 0.15 m
- OLR: 2.0-2.3 kgCOD/m3.d;- Batch: 6 h; 8 L/batch;- Cycle: Feeding: 30 min;
Reaction: 4h30min;Settling: 30 min; Discharge: 30min
- SRT: automatic washout;
Days38 790
Run I Run II Run III
0.8
2.2
0.6
Aeration rate (cm/s)
121
Introduce N2 gas
174
15/40 B.X. Thanh - 10417314-Jan-09
Continuous Granulation MBR (CG-MBR): Phase II
MBRHollow fibre
membrane module 0.42 m2
Air supply
Airlift reactor
System stop each 4 hr, settling 1 min
sludge discharge
Permeate P
sludge discharge(440 mL/4 h)
CG-MBR:Air supply: 1.7 cm/s (airlift);
0.1 cm/s (MBR)HRT: 10 hSRT: dependsFlux: 2.9 L/m2.hSuction: 7on/3offVolume 10 L (airlift)
3.5 L (MBR)
16/40 B.X. Thanh - 10417314-Jan-09
Operating Conditions: CG-MBR
RUN 1:OLR 2 kg COD/m3.dNLR 0.6 kg N/m3.d
OLR
RUN 2:OLR 4 kg COD/m3.dNLR 0.6 kg N/m3.d
RUN 3:OLR 8 kg COD/m3.dNLR 0.6 kg N/m3.d
Days50 880 120
17/40 B.X. Thanh - 10417314-Jan-09
BG-MBR Performance: Phase Ia
Page 53
Page 53
050
100150200250300350
Influent Settler MBRsupernatant
Permeate
TOC
(mg/
L)
104070100130160190220
TN (m
g/L)TOC TN
-50
0
50
100
150
200
250
Influent Settler MBRsupernatant
Permeate
conc
entra
tion
(mg/
L)
NH4-NNO2-NNO3-NTNSBAR: Organic removal & Partial Nitrification;
MBR: Nitrification & filtration;
18/40 B.X. Thanh - 10417314-Jan-09
Granule Characteristics in SBAR (Phase Ia)
14-Jan-09
Good settling (AS: < 10 m/h);High density & compact
Settling velocity (m/h)
500420
340260
180100
Freq
uenc
y
100
80
60
40
20
0
Mean: 131 m/hSD: 131N: 482
Granule size (mm)
876543
Freq
uenc
y
200
100
0
Mean: 4.68 mmSD: 1.35N: 500
Page 54
Page 54
B.X. Thanh
19/40 B.X. Thanh - 10417314-Jan-09
SBAR Performance – Organic Removal
050
100150200250300350
0 30 60 90 120 150 180 210 240
time (min)
TOC
(mg/
L)
0123456789
DO (m
g/L)
; pH
TOC DO pH
pH = 8.0 ± 0.2; DO = 4.0 – 7.8 mg/L;Organic matters are removed fast in 30 min (97.7 ± 1.4 %);
Page 51
20/40 B.X. Thanh - 10417314-Jan-09
SBAR Performance – Nitrogen Removal
0
40
80
120
160
200
0 30 60 90 120 150 180 210 240
time, min
conc
, mg/
L
NH4-N NO2-N NO3-N TN
+ Dynamic balance: NH4-N reduces NO2, NO3 N2 generated!
+TN removal 59% (SND= 47%, 22.2 mgN/L.h or 1.76 gN/gVSS.h);
SBARTNinf = 100%(190 mg/L)
TNeff = 41%(78 mg/L)
TNSND = 47%(89 mg/L)
Assimilation = 12%(23 mg/L)
TNremoved = 59% (112 mg/L)
Page 51
Page 52
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Membrane Fouling Behavior: Phase Ia
Fouling propensity of sludge fractions: Suspended Solids (SS), Colloids (CL) & Solutes (SL)
012
3456
78
0 25 50 75 100 125 150 175 200V, mL
t/V, s
/mL
SS-CL-SL CL-SLSL
Fouling potential of SS, CL & SL were 12%, 39% & 49%;Resistance percentage of SS, CL & SL were 2, 12 & 86 %;
Soluble matters is the major fouling contributor
Page 58
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Membrane Fouling – Soluble Fractions
0
5
10
15
20
settler MBR Permeate
conc
entr
atio
n (m
g/L)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
soluble PS soluble PNPS/EPS ratio
• Soluble PS increased in MBR (cell lysis, deflocculation)• PS/EPS > 0.8;• Soluble PS & PN deposited on membrane (11 mgPS/L.m2 & 8 mgPN/L.m2);• Soluble EPS extracted from membrane fibres: 20 µg/cm2 (after 78 days)
Release Deposition
Page 60
23/40 B.X. Thanh - 10417314-Jan-09
0
50
100
150
200
250
0 30 60 90 120 150 180day
SV
I (m
l/g)
0
2
4
6
8
10
MLS
S (g
/L)
SVI30 MLSS0.8 cm/s 2.2 cm/s 0.6 cm/s
N2 introduced
• Biomass conc. & settling ability increased impressively (SVI = 44 mL/g);• Anoxic growth improves aggregate density & promote aggregation;• Average effluent SS from SBAR reduced at Run III (200 to 50 mg/L).
Sludge characteristics
Effect of Aeration Rates & Anoxic growth on SBAR Effluent– Phase I b
200 µm200 µm
Page 68
24/40 B.X. Thanh - 10417314-Jan-09
Rt = ∆P/(J*µ)
0.00E+00
1.00E+12
2.00E+12
3.00E+12
4.00E+12
5.00E+12
0 40 80 120 160 200 240 280V (mL)
Rm
+Rf (
1/m
)
0.0E+00
4.0E+08
8.0E+08
1.2E+09
1.6E+09
0 0.25 0.5 0.75 1 1.25 1.5Pressure (bar)
dR/d
V (m
-1*s
-1)
Resistance Rate Calculation– Phase I b
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0.0E+00
5.0E+12
1.0E+13
1.5E+13
2.0E+13
0 0.25 0.5 0.75 1 1.25 1.5
dR/d
V (1
/m.L
)
SS-CL-SLCL-SLSL
0.0E+00
5.0E+12
1.0E+13
1.5E+13
2.0E+13
0 0.25 0.5 0.75 1 1.25 1.5
dR/d
V (1
/m.L
)
0.0E+00
5.0E+12
1.0E+13
1.5E+13
2.0E+13
0 0.25 0.5 0.75 1 1.25 1.5Pressure (bar)
dR/d
V (1
/m.L
)
0.8 cm/s 2.2 cm/s
0.6 cm/s + Anoxic/aerobic • At low aeration rate (0.8-0.6 cm/s):Resistance rates (SS, CL, SL) same order of magnitude;
• At high aeration rate (2.2 cm/s): resistance rates increases & resistance of SS plays a significant role release of small particles & SMPs.
• With anoxic: resistance slightly increases.
SS = 334 mg/L SS = 474 mg/L
SS = 97 mg/L
Resistance Rate in SBAR Effluent: Phase I b
Page 69
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0.0E+00
4.0E+11
8.0E+11
1.2E+12
Res
ista
nce
(1/m
)
0.0E+00
4.0E+11
8.0E+11
1.2E+12
Res
ista
nce
(1/m
)
0.0E+00
4.0E+11
8.0E+11
1.2E+12
Rf Rir Rrev
Res
ista
nce
(1/m
)
SS = 334 mg/L SS = 474 mg/L
SS = 97 mg/L Same trend as fouling rate;
• High aeration rate increasesirreversible fouling;
• Anoxic growth also increases irreversible fouling (due to soluble)
0.8 cm/s
2.2 cm/s
0.6 cm/s + Anoxic/aerobic
Irreversible/Reversible Resistance in SBAR Effluent: Phase I b
Reduction of aeration and improvement of denitrification leads to lower irreversible fouling
Page 70
27/40 B.X. Thanh - 10417314-Jan-09
Source SBAR Effluent SBAR Sludge
Aeration rate 0.8 cm/s 2.2 cm/s 0.6 cm/s + ano/aero 2.2 cm/s 0.6 cm/s C (kgSS/m3) 0.334 0.474 0.097 3.160 4.750Specific cake resistance - α(1012 m/kg) 27.2 20.1 214.0 7.5 1.6
An inverse trend for “Sludge” & “Effluent” behavior during filtration:
- Anoxic growth seems to have a negative impact on effluent (SMP)but a positive role on sludge filtration (aggregate densification).
- Specific cake resistance (α ) is always lower for Sludge than Effluent (due to particles properties and role of soluble)
Comparison of Specific cake resistance of Effluent & Sludge: Phase I b
Page 71
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Size exclusion chromatography (SEC) shows :
• Macromolecules (40-600 kDa) are increasingly produced at high aeration rate (2.2 cm/s),
• Compounds from 5.7- 6.2 kDa were especially released during denitrificationintensification (anoxic growth) and granular sludge formation
Characterization of soluble compounds by Chromatography
Hydrophobic Interaction Chromatography (HIC) shows :
• At high aeration rate, Supernatant in effluent contained larger (60%)hydrophobic fraction with low hydrophobic intensity;
• At low aeration rate with anoxic growth, supernatant in effluent contained lesshydrophobic fraction (20%) with high hydrophobic intensity.
Soluble Matters Characteristics: Phase I b
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Continuous Granulation MBR (CG-MBR): Phase II
0
20
40
60
80
100
0 20 40 60 80 100 120Day
Rem
oval
effi
cien
cy (%
)
0
1
2
3
4
5
OLR
(kgT
OC
/m3.
d)
TNDOCLoading
0
10
20
30
40
50
0 20 40 60 80 100 120Day
NO
2-N
and
NH
4-N
(mg/
L)
0
40
80
120
160
200
NO
3-N
(mg/
L)
NH4-N NO2-N NO3-N
+ Granule disintegrate CG-MBR=conventional MBR;+ TOC removal: 97.8, 99.0 & 99.4 % at OLR 2, 4, 8;+ TN removal: 20, 30 & 53%;+ Granule breakage TN removal reduced;
+ NO3 reduced, NO2, NH3increased at OLR 8;
+ Nitrifying activity ↓ at high OLR not compete with heterotrophs
Granule break
Page 75
Page 75
30/40 B.X. Thanh - 104173
0
20
40
60
0 10 20 30 40 50 60Day
TMP
(kPa
)
OLR 2OLR 4OLR 8
14-Jan-09
Fouling Propensity of CG-MBR: Phase II
+ Cake build-up TMP “jump”+ Cake resistance > 87.5 %
Fouling rate (kPa/d)
Cake build up
Page 78
y = 4.67x2 - 7.94x + 3.47R2 = 1.00
y = 3.03x - 1.50R2 = 0.94
y = 8.15x - 4.06R2 = 0.97
0.0
0.5
1.0
1.5
2.0
2.5
0 0.5 1 1.5 2F/M (1/d)
Foul
ing
rate
(kPa
/d)
0
2
4
6
8
10
Load
ing
rate
(kg/
m3.
d)Fouling rate
TOC loading
COD loadingPage 78
+ Fouling rate proportional to F/M ratio (2rd order); OLRs (1st order);+ Membrane contacts with high amount of organic matters fouling.
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0
10
20
30
40
0 20 40 60 80 100 12Day
Perm
eate
(mg/
L)
PSPNDOC
Behavior of Soluble Matters in CG-MBR
0
10
20
30
40
0 20 40 60 80 100 120Day
Supe
rnat
ant (
mg/
L)
PSPNDOC
+ Soluble matters (DOC, Polysaccharides, Protein): (Supernatant > Permeate!) deposited on membrane ;
Deposition rates (mg/L.m2
membrane)OLR (kgCOD/m3.d)
2 4 8DOC 16.3 18.2 17.2sPS 13.1 11.3 13.7sPN 5.6 5.0 6.7sEPS 18.7 16.3 20.5
Page 79 Page 79
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Comparison: BG-MBR vs CG-MBR
0
20
40
60
BG-MBR CG-MBR
TN re
mov
al (%
)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Foul
ing
rate
(kPa
/d) &
F/M
(1/d
)
TN removalFouling rateF/M
+ Granule was instable in CG-MBR higher F/M, higher fouling and lower N removal.
+ Granule stuck on the membrane fibres (lack shear stress) Flatsheet module is suitable for granulation MBR!
Page 80
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Comparison: Treatment Systems
Items Anaerobic reactor Submerged MBR BG-MBROperating temp. (oC) 30-55 25-35 8-55Energy requirement (kWh/m3)
0.1 0.9 1.6
Sludge failure Possible - Possible Shock load resistance Possible - YesStart-up time (days) 100 10 30MLSS (g/L) 2-60 (depends) 8-15 Up to 18 g/L (2-4 g/L: MBR)SRT (day) 10-300 15-30 10-100*SVI (mL/g) 10-280 120-250 mL/g 10-40 mL/gSettling velocity (m/h) < 10 < 10 20-100 (higher for granule)Particle size (µm) 0.5-8.0 mm (granule)
0.3-200 (flocs)1-250 (flocs) 0.5-9.0 mm (granules)
0.3-301.7 (flocs in MBR)OLR (kg COD/m3.d) Up to 40 < 8 2-30SND No Possible Good (1.76 mgTN/gVSS.h)Fouling potential - High (0.168 kPa/d) Less (0.027 kPa/d)
BG-MBR shows the potential application for high strength C, N wastewater
Page 82
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Conclusions
+ BG-MBR system:
+ Ability for C & N removal. The SND at OLR of 2 kgCOD/m3.d was 47% or 22 mgTN/L.h (1.76 mgTN/gVSS.h).
+ Aerobic granules disintegrated under anaerobic condition and long SRT.
+ Release of soluble matters in MBR depends on the HRT which influences the fouling propensity & supernatant quality. SMPs are the main cause for fouling where polysaccharides were dominant (11 mg/L.m2 & 8 mg/L.m2
for sPS & sPN).
+ The disintegration of granules resulted in the release of SMPs that increased the fouling propensity of the BG-MBR system
CG-MBR system:+ Granule is disintegrated in continuous operation mode (CG-MBR);
+ Fouling rate showed 2rd order increment with F/M ratio & 1st order with OLR.
+ SMPs deposited on membrane.
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Conclusions (cont’d)
Effect of aeration rates:
+ The anoxic/aerobic conditions enhanced the biomass retention, settling ability, denitrification & filterability.
+ Resistance rate & specific cake resistance of SBAR effluent were higher than that of sludge in anoxic/aerobic operation despite higher SS.
+ Resistance & irreversible resistance of SBAR effluent were increased at high aeration rate (2.2 cm/s) due to release of macromolecules (30-50 kDa) & small particles while SMPs were released at lower aeration rate (0.8 cm/s).
+ At high aeration rate (2.2 cm/s), 60% of the hydrophobic fraction was found in the soluble fraction of SBAR effluent with low hydrophobic intensity. While at the low aeration rate (0.6 cm/s + anoxic growth), 20% of the hydrophobic fraction was found with high hydrophobic intensity.
+ BG-MBR showed better operational performance than CG-MBR (granule stability, N removal & fouling propensity).
+ Higher biomass retention in BG- MBR compared to CG-MBR lower F/M lower fouling.
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Recommendations
+ Study on the granule stability at various SRT & sludge removal methods (mixed sludge, top sludge, & bottom sludge).
+ To accelerate and stabilize the granulation process, methods namely support media addition, bridging polymer addition, aeration rates, cycle length, etc should be investigated and optimized.
+ In BG-MBR, HRT of MBR affects the release of SMPs relates fouling Investigate fouling and sludge characteristics at various HRT.
+ Study on the possibility of granulation and fouling characteristics in sequencing batch MBR in which membrane functions as an ideal decanter in a SBR. The light fraction of sludge is removed periodically (feast/famine).
+ SMPs played an important role in fouling of granulation MBR study on the quality and quantity of soluble fraction through SEC-EEM-DOC for understanding the nature of foulants at certain operating conditions
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Recommendations (Cont’d):Proposed Batch Granulation-MBR
Air supply
Permeate Effluent
SBAR
Setller-combined MBR
Up level
Down level
Sludge withdrawalSettlingchamber
MBR chamber
Settler-combined MBR
Recirculation
+ Investigate compacted BG-MBR which membrane is integrated in an aerated zone of settler.
+ Recirculation ratio from aeration zone to settling zone can improve further N removal.
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Recommendations (Cont’d):Proposed CG-MBR
+ Study on the application of flat-sheet membrane in CG-MBR. This semi-continuous system can maintain granule stability
(Sludge discharge interval 1-4 h,to control feast-famine condition).
P
Sludge discharge pump (each 4 h)
Influent pump (continuous)
Permeate pump (on/off cycle)
Flatsheet membrane
module
Air scouring
Air supply
Level sensor
Granules
Remark: Granulation Membrane Airlift BioreactorEach 4 h, system stops and sludge settling for 1-2 minute
sludge discharge
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Publications
Thanh, B.X., Visvanathan, C., Spérandio, M., Ben Aim, R. (2008). Fouling characterization in aerobic granulation coupled MBR, Journal of Membrane Science, 318 (1-2), 334-339.
Thanh, B.X., Visvanathan, C., Ben Aim, R. (2009). Characterization of aerobic granules at various organic loading rates, Process Biochemistry, 44, 242-245.
Thanh, B.X., Visvanathan, C., Ben Aim, R. (Submitted). Fouling behavior in external submerged MBR treating granulation effluent, Separation Purification and Technology.
Thanh, B.X., Sperandio, M., Guigui, C., Ben Aim, R., Wan, J.F., Visvanathan, C. (2008). Coupling SBAR and membrane filtration: Influence of nitrate removal on sludge characteristics, effluent quality and filterability, Conference on Membranes in Drinking Water Production and Wastewater Treatment, Oct 20th-22nd, 2008, Toulouse, France.
Jegatheesan, V., Shu, L., Visvanathan, C., Thanh, B.X. (2008). Aerobic Environmental Process: Chapter 23 in Advances in Fermentation Technology, Ed. Pandey et al., pp. 622-654, Asiatech Press, New Delhi. ISBN: 81-87680-18-0.
Journal Publications:
Book chapter:
IWA International Conferences:
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Thank you for your attention!