AnMBR technologies (CSTR and UASBtype) for winery wastewater treatment
at low temperatures
N. Basset*, M.E. de Arana-Sarabia**, C. Vidal*, A. Coll*, I. Fernández*, J. Dosta* and J. Mata-Álvarez*
*Department of Chemical Engineering and Analytical Chemistry, University of Barcelona
**Department of Engineering and Architecture, University of Trieste
- INTRODUCTION- Winery wastewater
- CSTR-MBR- Set up and winery wastewater
- Objectives and operational conditions
- Results
- Microbial populations
- UASB-MBR- Objectives, set up and operational conditions
- Results
- Microbial populations
- CONCLUSIONS
LAYOUT OF THE PRESENTATION
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France16%
Italy16%
Spain12%
USA8%
China6%
Australia5%
Chile5%
Rest of the world32%
France
Italy
Spain
USA
China
Australia
Chile
Rest of the world
Wine production (·103hL)(source: International Organization of Vine and Wine )
Country 2010 2011 2012France 44322 50757 41422
Italy 48525 42772 40060Spain 35353 33397 30392USA 20887 19187 20517
China 13000 13200 14880Australia 11420 11180 12660
Chile 8844 10464 12554
Rest of the world 81649 86043 79515
Total 264000 267000 252000
World wine production
Up to 4 L wastewater L-1 wine produced
• High organic loads
• Low nutrient content
• Seasonal variability
• Relatively small facilities
Intensive and compact technologies: AnMBR
Energy recovery
Introduction: winery wastewater
CSTR-MBR: Set up and winery wastewater
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Winery wastewater characteristics and CSTR-MBR set up
Anaerobic CSTR of 4L coupled to an external membrane unit
PVDF flat-sheet
0.25 µm pore size
100 cm2 of area
TMP = 0.2 bar
Biogas counter:
Ritter MGC-1
Feed by pressure equilibrium
Peristaltic
pump 30 L/h
Winery wastewater main characteristics
pH 4.67 ± 0.42
tCOD (mg/L) 6752 ± 663
sCOD (mg/L) 4040 ± 692
NH4+-N (mg/L) 4.99 ± 1.66
PO43—P (mg/L) 4.55 ± 1.63
COD/N 1352
COD/P 1484
Orelis, Rayflow Module
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Objectives
Test the AnMBR at low temperatures of 25ᵒC and 15ᵒC
• COD removal
• Biogas production
• Fouling
• Microbial population
Operational conditions
HRT = 4 days
SRT = 500 days
Influent COD = 1-1.5g/L
MLSS = 2.7 g/L
Alkalinity = 900 mg/L
TMP = 0.2 bar
Vc = 0.64 m/s
CSTR-MBR: Objectives and operational conditions
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25ᵒC
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VFA
(m
g L-1
)
CO
D r
em
ova
l (%
)
COD removal VFA
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sOLR
(kg
CO
D k
g-1M
LSS
d-1
)
Flu
x (L
MH
)
Time (d)
Flux Cleaning sOLR
15ᵒC
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MH
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Flux Cleaning sOLR
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VFA
(m
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CO
D r
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ova
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)
COD removal VFA
High VFA
High sOLR
Acclimation
High VFA
High sOLR
After a cleaning, flux and sOLR increased
80% COD removal
70% COD removal
CSTR-MBR: Results
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Results summary and comparison
Operational parameters
Temperature 15ᵒC 25ᵒC 35ᵒC
COD influent (g L-1) 1.10±0.30 1.41±0.39 2.92±1.05
COD effluent (g L-1) 0.39±0.15 0.28±0.14 0.14±0.23
%COD removal 71±9 80±9 96±4
OLR (kgCOD m-3digester d-1 ) 0.29±0.21 0.35±0.19 1.32±0.51
sOLR (kgCOD kg-1MLSS d-1 ) 0.11±0.07 0.13±0.09 0.22±0.09
Membrane performance
Flux (LMH) 13.8±6.8 12.2±4.4 16.0±3.9
Flux decline (LMH d-1) 3.36±1.03 2.14±1.62 0.10±0.04
Effluent COD higher due to VFA
Higher degree of fouling at similar
fluxes
CSTR-MBR: Results
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FISH
15ᵒCMethanosaeta spp.
Methanosarcina spp. High VFA in the digester
CSTR-MBR: Microbial populations
25ᵒC 25ᵒC
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Objectives
The Upflow Anaerobic Sludge Blanket (UASB) is one of the most used configuration
Interesting to apply at low temperature anaerobic digestion, higher biomass concentration
Improve the subsequent filtration step due to low SS in the clarified effluent
Winery wastewater treatment at room temperature (20 ᵒC)
• UASB without membrane
• UASB-MBR
Volume = 1.5 L
HRT = 16 h
H/D = 3
MLSS = 30-40 g/L
Upflow velocity = 1 m/h
UASB-MBR: Objectives, set up and operational conditions
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Higher OLR up to 5.5 kgCOD m-3 d-1
Lower sOLR <0.06 kgCOD kgMLSS-1 d-1
MLSS around 40 g L-1
Effluent COD > 125 mg L-1 (effluent SS↑)Effluent sCOD < 125 mg L-1
Upflow anaerobic sludge blanket (UASB)
COD removal of 80%SMP of 0.20 Nm3CH4 kg-1CODadded
97% of methane in biogas
UASB-MBR: Results: UASB
Important wash out of solids in the effluent
Good sCOD removal, not very good total COD removal
Introduction of the membrane: UASB-MBR
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UASB-MBRCOD removal > 90%
SMP of 0.17 Nm3CH4 kg-1CODadded
95% of methane in biogasEffluent free of SS
Minimise losses of SS in the effluent
Accomplish discharge limits
Avoid biomass wash-out
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D r
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CO
D (
g L-1
)
Time (d)
Influent COD Permeate COD COD removal (%)
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OLR
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Dm
-3d
-1)
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x (L
MH
)
Time (d)
Flux OLR
UASB-MBR: Results: UASB-MBR
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Microbial population (FISH)
Methanosaeta was the main methanogen
Methanosaeta spp.
Archaea
Bacteria
Although VFA were present in the effluent, Methanosarcina spp. was not detected
Granules protect methanogens so VFA concentration may be lower in the inner layers
UASB-MBR: Results: Microbial populations
CSTR-MBR and UASB-MBR were successfully treating winery wastewater at lowtemperatures. (COD removal: 71% CSTR-MBR at 15 °C, 80% CSTR-MBR at 25 °C, 92%UASB-MBR at 22 °C)
Both reactors showed acclimation to the typical seasonal variability of the winerywastewater (low load and low temperature in winter and high load and relativelyhigh temperature in summer).
Due to the VFA accumulation and the dissolved methane, a post-treatment of theeffluent would be necessary to meet the legislation. On the other hand, after thatpost-treatment, the solids-free effluent would be appropriate for a potential reuse.
Higher degree of fouling compared with mesophilic AnMBR was observed. Thisfouling level was similar in both CSTR-MBR and UASB-MBR.
The microbial population in the CSTR-MBR shifted from Methanosaeta spp. toMethanosarcina spp. because the high VFA concentration favoured the developmentof acetotrophic methanogens with higher growth rate under high acetateconcentration.
Conclusions
AnMBR technologies (CSTR and UASBtype) for winery wastewater treatment
at low temperatures
Thank you for your attention
