AnMBR technologies (CSTR and UASB type) 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
LAYOUT OF THE PRESENTATION - 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
Introduction: winery wastewater World wine production Wine production (·10 3 hL) France (source: International Organization of Vine and Wine ) Country 2010 2011 2012 Italy France France 44322 50757 41422 16% Rest of the Spain Italy 48525 42772 40060 world USA Spain 35353 33397 30392 Italy 32% USA 20887 19187 20517 16% China Chile China 13000 13200 14880 5% Australia Spain Australia 11420 11180 12660 12% Chile 8844 10464 12554 Chile Australia Rest of the world 81649 86043 79515 5% China USA Rest of the world 6% 8% Total 264000 267000 252000 Up to 4 L wastewater L -1 wine produced • High organic loads • Low nutrient content Intensive and compact Energy • Seasonal variability technologies: AnMBR recovery • Relatively small facilities 3
CSTR-MBR: Set up and winery wastewater Winery wastewater characteristics and CSTR-MBR set up Winery wastewater main characteristics pH 4.67 ± 0.42 tCOD (mg/L) 6752 ± 663 sCOD (mg/L) 4040 ± 692 NH 4 + -N (mg/L) 4.99 ± 1.66 PO 4 3 — P (mg/L) 4.55 ± 1.63 Orelis, Rayflow Module COD/N 1352 COD/P 1484 Anaerobic CSTR of 4L coupled to an external membrane unit Biogas counter: Peristaltic PVDF flat-sheet Ritter MGC-1 pump 30 L/h 0.25 µm pore size 100 cm 2 of area TMP = 0.2 bar Feed by pressure equilibrium 4
CSTR-MBR: Objectives and operational conditions 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 V c = 0.64 m/s 5
CSTR-MBR: Results 25ᵒC 15ᵒC 80% COD 70% COD removal removal COD removal VFA COD removal VFA 100 600 100 450 400 500 High VFA 80 350 75 COD removal (%) COD removal (%) VFA (mg L -1 ) 400 300 VFA (mg L -1 ) 60 High VFA 250 50 Acclimation 300 200 40 150 200 25 100 20 100 50 0 0 0 0 30 0,35 30 0,40 sOLR (kgCOD kg -1 MLSS d -1 ) 0,35 0,30 High sOLR 25 sOLR (kgCOD kg -1 MLSS d -1 ) High sOLR 25 0,30 0,25 20 20 Flux (LMH) 0,25 Flux (LMH) 0,20 15 0,20 15 0,15 0,15 10 10 After a cleaning, flux and sOLR increased 0,10 0,10 5 5 0,05 0,05 0 0,00 0 0,00 0 5 10 15 20 25 30 35 40 45 45 55 65 75 85 95 105 Time (d) Time (d) Flux Cleaning sOLR Flux Cleaning sOLR 6
CSTR-MBR: Results 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 Effluent COD higher COD effluent (g L -1 ) 0.39 ± 0.15 0.28 ± 0.14 0.14 ± 0.23 due to VFA %COD removal 71 ± 9 80 ± 9 96 ± 4 digester d -1 ) OLR (kgCOD m -3 0.29 ± 0.21 0.35 ± 0.19 1.32 ± 0.51 sOLR (kgCOD kg -1 MLSS 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 Higher degree of Flux decline (LMH d -1 ) 3.36 ± 1.03 2.14 ± 1.62 0.10 ± 0.04 fouling at similar fluxes 7
CSTR-MBR: Microbial populations FISH 25ᵒC 25ᵒC 15ᵒC Methanosaeta spp. Methanosarcina spp. High VFA in the digester 8
UASB-MBR: Objectives, set up and operational conditions 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 Objectives 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 9
UASB-MBR: Results: UASB Upflow anaerobic sludge blanket (UASB) Higher OLR up to 5.5 kgCOD m -3 d -1 Lower sOLR <0.06 kgCOD kgMLSS -1 d -1 COD removal of 80% SMP of 0.20 Nm 3 CH 4 kg -1 COD added MLSS around 40 g L -1 Effluent COD > 125 mg L -1 (effluent SS↑) 97% of methane in biogas Effluent sCOD < 125 mg L -1 Important wash out of solids in the Introduction of the effluent membrane: Good sCOD removal, not very good UASB-MBR total COD removal 10
UASB-MBR: Results: UASB-MBR UASB-MBR COD removal > 90% Minimise losses of SS in the effluent SMP of 0.17 Nm 3 CH 4 kg -1 COD added Accomplish discharge limits 95% of methane in biogas Effluent free of SS Avoid biomass wash-out Influent COD Permeate COD COD removal (%) Flux OLR 30 3,0 2,0 100% 25 2,5 OLR (kgCOD m -3 d -1 ) 80% 1,5 COD removal Flux (LMH) 20 2,0 COD (g L -1 ) 60% 15 1,5 1,0 40% 10 1,0 0,5 20% 5 0,5 0,0 0% 0 0,0 0 5 10 15 20 25 30 35 40 45 0 5 10 15 20 25 30 35 40 45 Time (d) Time (d) 11
UASB-MBR: Results: Microbial populations Microbial population (FISH) Archaea Bacteria Methanosaeta spp. Methanosaeta was the main methanogen 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 12
Conclusions CSTR-MBR and UASB-MBR were successfully treating winery wastewater at low temperatures. (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 winery wastewater (low load and low temperature in winter and high load and relatively high temperature in summer). Due to the VFA accumulation and the dissolved methane, a post-treatment of the effluent would be necessary to meet the legislation. On the other hand, after that post-treatment, the solids-free effluent would be appropriate for a potential reuse. Higher degree of fouling compared with mesophilic AnMBR was observed. This fouling level was similar in both CSTR-MBR and UASB-MBR. The microbial population in the CSTR-MBR shifted from Methanosaeta spp. to Methanosarcina spp. because the high VFA concentration favoured the development of acetotrophic methanogens with higher growth rate under high acetate concentration.
AnMBR technologies (CSTR and UASB type) for winery wastewater treatment at low temperatures Thank you for your attention
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