Mesophilic and Thermophilic anaerobic co digestion of winery wastewater sludge and wine lees: an integrated approach for wine industry

Mesophilic and Thermophilic anaerobic co digestion of winery wastewater sludge and wine lees: an integrated approach for wine industry C. Da Ros 1, C. Cavinato 1, P. Pavan 1, D. Bolzonella 2 1 Department of Environmental Sciences, Informatics and Statistics, University Ca Foscari of Venice, Calle Larga Santa Marta 3123 Venice, Italy. 2 Department of Biotechnology, University of Verona, Strade le Grazie 15, 37134 Verona, Italy. 1

Trends in world wine production: stable production of 27 millions hl per year in the last 15 years 2

214 wine production per country 3

214 wine production per country: Europe leads 4

Environmental impacts of wine production. Waste «pressure».. 5

Wastewater (and then sludge) 6

Wastewater (and then sludge) Grape pomace

Wastewater (and then sludge) Grape pomace Stalks 8

Wastewater (and then sludge) Grape pomace Stalks Lees 9

Winery Wastes Wastewater 2 4 l/hl of wine produced Organic waste: 4 6 kg/hl of wine produced Stalks 12% Lees 14% Wastewater sludge 12% Grape pomace 62% Ruggieri et al., 29 1

Integrated treatment of winery wastes by ANAEROBIC DIGESTION 11

Integrated treatment of winery wastes by ANAEROBIC DIGESTION 12

Integrated treatment of winery wastes by ANAEROBIC DIGESTION VINASSES (AFTER DISTILLATION) 13

Why anaerobic digestion?? 14

Why anaerobic digestion?? > 86 14, AD plants operating within EU Some 8, MW installed power Some 3 plants for biomethane upgrade 15

Why anaerobic digestion?? Digestate: a renewable fertilizer and carbon sequestrer 16

Mesophilic and Thermophilic anaerobic co digestion of winery waste and sludge A pilot scale trial 17

Substrates characteristics Parameter Unit Waste Activated Sludge Wine Lees average std.dev range average std.dev range TS gts/kg ww 158.9 49.3 22.7 267.8 62. 27.9 12.3 12. VS gvs/kg ww 143.5 41.6 2.7 237.3 33.6 15.1 1.3 73. VS/TS % 88% 3 79 93% 57% 13% 29 86% COD mg/g TS 868 69.4 749 18 559 151 312 919 scod g/l nd nd nd 167 45 111 24 TKN mg N NH 4+ /g TS 52.7 16.3 14.5 8.3 3.3 12.7 9.7 68.7 NH + 4 mg N NH 4+ /l nd nd nd 33.9 22.7 6.7 95.3 P tot mg P PO 3 4 /g TS 7.3 2. 2.5 1.7 6.2 2.9 2.6 14.3 Polyphenols mg HGal/l nd nd nd 1537 1189 26 3,98 18

Substrates characteristics Parameter Unit Waste Activated Sludge Wine Lees average std.dev range average std.dev range TS gts/kg ww 158.9 49.3 22.7 267.8 62. 27.9 12.3 12. VS gvs/kg ww 143.5 41.6 2.7 237.3 33.6 15.1 1.3 73. VS/TS % 88% 3 79 93% 57% 13% 29 86% COD mg/g TS 868 69.4 749 18 559 151 312 919 scod g/l nd nd nd 167 45 111 24 TKN mg N NH 4+ /g TS 52.7 16.3 14.5 8.3 3.3 12.7 9.7 68.7 NH + 4 mg N NH 4+ /l nd nd nd 33.9 22.7 6.7 95.3 P tot mg P PO 3 4 /g TS 7.3 2. 2.5 1.7 6.2 2.9 2.6 14.3 Polyphenols mg HGal/l nd nd nd 1537 1189 26 3,98 19

Pilot scale anaerobic reactors Two parallel CSTR reactors Volume reactors: 23 l Organic load: avg 3.2 kgcod/m 3 d HRT: avg 23 d Temperature: 37 C & 55 C 2

Mesophilic process N NH4+(mg/l) 7 6 5 4 3 2 1 N NH4+ ph 1 2 3 time(d) 9 8,5 8 7,5 7 6,5 6 5,5 5 4,5 4 ph Process 35 was stable: ph 7.46 3 25 N NH4+: 4 mg N NH4+ 2 TS, VS (g/kg) VFA < 2 mgcod/l 15 Total alkalinity: 2,248 mgcaco3/l 1 VS TS 5 1 2 3 time(d) Polyphenols (mghgal/l) 9 8 7 6 5 4 3 2 1 Polyphenols 1 2 3 time(d) SGP(m3/kgCOD)),5,45,4,35,3,25,2,15,1,5 SGP 1 2 3 time(d) 21

Mesophilic process N NH4+(mg/l) 7 6 5 4 3 2 Improve of degradation efficiencies in the long period: Biomass acclimatation 1 N NH4+ ph 1 2 3 time(d) 9 8,5 8 7,5 7 6,5 6 5,5 5 4,5 4 ph TS, VS (g/kg) 35 3 25 2 15 1 5 VS TS 1 2 3 time(d) Polyphenols (mghgal/l) 9 8 7 6 5 4 3 2 1 Polyphenols 1 2 3 time(d) SGP(m3/kgCOD)),5,45,4,35,3,25,2,15,1,5 SGP 1 2 3 time(d) 22

Mesophilic process N NH4+(mg/l) 7 6 5 4 3 2 1 N NH4+ ph 1 2 3 time(d) 9 8,5 8 7,5 7 6,5 6 5,5 5 4,5 4 ph TS, VS (g/kg) 35 3 25 2 15 1 5 VS TS 1 2 3 time(d) Polyphenols (mghgal/l) 9 8 7 6 5 4 3 2 1 Polyphenols Average biogas producton:.39 m 3 /kgcod with 64 73% of methane 1 2 3 time(d) SGP(m3/kgCOD)),5,45,4,35,3,25,2,15,1,5 SGP 1 2 3 time(d) 23

Thermophilic process N NH4+(mg/l) 12 1 8 6 4 2 5 1 time(d) N NH4+ ph 9 8,5 8 7,5 7 6,5 6 5,5 5 4,5 4 ph SGP(m3/kgCOD),5,45,4,35,3,25,2,15,1,5 SGP 2 4 6 8 1 12 14 time(d) Volatile fatty acids accumulated (6 gcod/l) VFAs in the bulk were composed mainly by acetic and propionic acids (78% and 1% respectively) ph fell down to 5.3 Specific gas production and methane content reduced 24

Was methanogenic activity inhibited by missing trace elements? Takashimaiet al., 211 25

Different addition of trace elements in the feed mixture RUN RUN 1 RUN 2 RUN 3 RUN 4 Fe (mg/l) 4.3 3.1 2.15.86 Ni (mg/l).46.32.23.9 Co (mg/l).51.36.25.1 Values suggested by Takashima et al., 211 7% of 5% of 2% of REFERENCE VALUE REFERENCE VALUE REFERENCE REFERENCE VALUE VALUE 26

Specific biogas production SGP (m3/kgcod) 1,9,8,7,6,5,4,3,2,1 RUN 2 RUN1 RUN3 RUN2 RUN4 1 2 3 4 time (days) 55 C AVERAGE 37 C 27

Comparison of operational conditions 55 C Parameter Unit 37 C RUN RUN1 RUN2 RUN3 RUN4 Stability parameters ph 7.38 6.7 7.91 7.78 7.82 7.9 TA mg CaCO 3 /l 2287 3673 339 2439 362 323 N NH + 4 mg N NH 4+ /l 373 82 63 455 665 644 Digestate characteristics TS gts/kg ww 24.7 31.9 21.3 19.8 22.1 2.3 VS gvs/kg ww 14.3 19.5 12.1 13.3 11.6 11.5 VS/TS % 58 61 57 67 52 61 COD mg COD/gTS 614 671 613 68 62 556 scod mg COD/l 391 5394 852 74 87 882 TKN mg N NH 4+ /gts 37.9 4.4 32.8 35.9 37.6 33.1 P tot mg P PO 3 4 /gts 8 11.1 1.2 11.3 9.8 8.5 Polyphenols mg HGal/l 26 153 66 61 57 Yields SGP m 3 /kgcod.386.39.454.386.381.347 COD removal % 79% 88% 73% 7% 65% Stability parameter in the optimal range for anaerobic digestion Higher polyphenols removal with metals adition Highest dosage of metals improved biogas prodcution in comparison with mesophilic process 28

Digestate dewaterability: mesophilic & thermophilic with maximum metal augmentation 3 1 CST (s) 25 2 15 1 SRF (x112 m/kg) 1 1 5 2 4 6 8 1 conditioner dose (g/kgts) 1 2 4 6 8 1 conditioner dose (g/kgts) 37 C 55 c meccanically filtrable 37 C 55 C meccanically filtrable 29

Final remarks Winery waste sludge and wine lees could be easily co treated by mesophilic anaerobic digestion (SGP:.39 m 3 /kgcod) Thermophilic digestion showed instability, with accumulation of acetic and propionic acids and methanogenic inhibition Addition of trace elements (Fe, Co and Ni) in thermophilic reactor improved process stability Dewaterability tests showed that mesophilic digestate performed better Higher costs for metals and flocculants for thermo AD should be kept in mind! 3

Organised by the Specialist Group on Winery Waste Management of the International Water Assocition 31