HERAKLION 2019 International Conference on Sustainable Solid Waste - PowerPoint PPT Presentation

HERAKLION 2019 International Conference on Sustainable Solid Waste Management 26 – 29 June 2019 Application of semi-continuous pilot-scale AD tests to assess biochemical methane potential and hydrolysis rate constant of raw and pre-treated sludge G. Campo 1 , A. Cerutti 1 , M.C. Zanetti 1 , G. Scibilia 2 , E. Lorenzi 2 , B. Ruffjno 1 1 Department Environment, Land and Infrastructure Engineering, Politecnico di T orino, T orino, I-10129, Italy 2 Research Center, Società Metropolitana Acque T orino S.p.A., Viale Maestri del Lavoro, 4 – 10127 T orino, Italy http://www.wearwe.polito.it

Castiglione T orinese WWTP Municipal and industrial wastewater Capacity: 2,000,000 E.I. Average fmow rate: 7 m 3 /s

Pre-treatments Low thermal, alkali and low temperature thermo-alkali pretreatments Polito-Smat Low temperature thermo – alkali pre-treatment 4kg NaOH /100kg TS, 90 °C, 1.5h “Review of feedstock pretreatment strategies for improved anaerobic digestion: From lab-scale research to full-scale application” Carrere H., Antonopoulou G., Afges R., Passos, Battimelli A., Lyberatos G,Ferrer I. (2016) Review of feedstock pretreatment strategies for improved anaerobic digestion: From lab-scale research to full-scale application Bioresour. T echnol.Vol. 199, 386–397

Reactor Batch khyd Bo 0,5 0,5 B(t) 0,4 B(t) 0,4 0,3 0,3 0,2 0,2 0,1 0,1 0 0 5 10 15 20 25 30 35 40 0 0 5 10 15 20 25 30 35 40 t t CST Reactor

CSTR Digester Biogas ? VS b ? VS b ? VS nb VS nb NVS NVS

CSTR Digester Biogas VS b VS b VS nb VS nb NVS NVS

Pilot Anaerobic digestion tests Mesophilic Anaerobic Digestion (38°C) Secondary Sludge Primary Sludge

Experimental 0,04 0,04 0,03 0,03 Nm3 0,02 0,02 0,01 0,01 0,00 0 12 24 36 48 60 72 84 96 108 120 132 144 156 0,00 Days

Experimental Cumulative methane 3,5 production 3,0 2,5 Secondary Sludge 2,0 Nm3 1,5 1,0 Calibration 0,5 0,0 0 12 24 36 48 60 72 84 96 108 120 132 144 156 Days Daily methane production 0,040 0,035 1/3 0,030 0,025 Nm3/d 0,020 0,015 0,010 0,005 0,000 0 12 24 36 48 60 72 84 96 108 120 132 144 156 -0,005 Days

Model Experimental Cumulative methane 3,5 production 3,0 = 0.147 [Nm 3 /kgVS] 2,5 Secondary Sludge ] 2,0 Nm3 1,5 1,0 Calibration 0,5 0,0 0 12 24 36 48 60 72 84 96 108 120 132 144 156 Days Daily methane production 0,040 0,035 1/3 0,030 0,025 Nm3/d 0,020 0,015 0,010 0,005 0,000 0 12 24 36 48 60 72 84 96 108 120 132 144 156 -0,005 Days

Cumulative methane Model Experimental production 3,5 = 0.250 Nm 3 /kgSV 3,0 2,5 Secondary Sludge 2,0 Nm3 1,5 Pre-treatment: 90 °C - 1,5 h – 4g NaOH/100gST 1,0 Calibration 0,5 0,0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Daily methane production Days 0,100 0,090 0,080 2/3 0,070 0,060 Nm3 0,050 0,040 0,030 0,020 0,010 0,000 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Days

Cumulative methane Model Experimental production 3,5 = 0.250 Nm 3 /kgSV + 71% 3,0 2,5 + 447% Secondary Sludge 2,0 Nm3 1,5 Pre-treatment: 90 °C - 1,5 h – 4g NaOH/100gST 1,0 Calibration 0,5 0,0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Daily methane production Days 0,100 0,090 0,080 2/3 0,070 0,060 Nm3 0,050 0,040 0,030 0,020 0,010 0,000 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 Days

Cumulative methane Model Experimental 0,30 production 0,25 = 0.300 Primary 0,20 Nm 3 /kgSV Nm3 0,15 sludge 0,10 Calibration 0,05 0,00 0 12 24 36 48 60 72 84 96 108 120 132 144 156 Daily methane production Days 0,0040 0,0035 0,0030 3/3 0,0025 0,0020 Nm3 0,0015 0,0010 0,0005 0,0000 0 12 24 36 48 60 72 84 96 108 120 132 144 156 -0,0005 Days

90 °C - 1,5 h – 4g NaOH/100gST Validatio Secondary sludge Primary n sludge Cumulative methane production Sperimentale Daily methane production 4,50 0,0700 4,00 0,0600 3,50 0,0500 3,00 2,50 0,0400 Nm3 Nm3 2,00 0,0300 1,50 0,0200 1,00 0,0100 0,50 0,00 0,0000 0 12 24 36 48 60 72 84 96 0 12 24 36 48 60 72 84 96 Days Days

Validatio Secondary = 0.250 Nm 3 /kgVS sludge Primary n = 0.300 Nm 3 /kgVS sludge Modello Cumulative methane production Daily methane production Sperimentale 4,50 0,0700 4,00 0,0600 Error 1.1% 3,50 0,0500 3,00 2,50 0,0400 Nm3 Nm3 2,00 0,0300 1,50 0,0200 1,00 0,0100 0,50 0,00 0,0000 0 12 24 36 48 60 72 84 96 0 12 24 36 48 60 72 84 96 Days Days

WAS A.D. in WWTP Castiglione Torinese Present conditions WAS Mesophilic AD 38 °C k = 0.09 1/d B O = 0.147 Nm 3 /kg VS B 20d = 0.09 Nm 3 /kg VS

WAS A.D. in WWTP Castiglione Torinese Present conditions Scenario 1 WAS WAS Mesophilic AD 38 °C Pretreatment + AD 38°C NaOH 4g/100g TS 90 °C, 1,5h k = 0.09 1/d k = 0.46 1/d B O = 0.147 Nm 3 /kg B O = 0.250 Nm 3 /kg VS VS B 20d = 0.09 B 20d = 0.226 Nm 3 /kg VS Nm 3 /kg VS + 144 %

WAS A.D. in WWTP Castiglione Torinese Present conditions Scenario 2 Scenario 1 WAS WAS WAS Thermophilic AD 55 °C y Mesophilic AD 38 °C Pre-treatment + AD 38°C a NaOH 4g/100g TS d 90 °C, 1,5h r k = 0,380 1/d k = 0.09 1/d k = 0.46 1/d e B O = 0,218 Nm 3 /kg B O = 0.147 Nm 3 /kg B O = 0.250 Nm 3 /kg VS t s VS VS e Y B 20d = 0,193 B 20d = 0.09 B 20d = 0.226 Nm 3 /kg VS Nm 3 /kg VS Nm 3 /kg VS + 108 + 144 % %

Conclusions: • The proposed first order kinetic model can be used as a tool in order to obtain a good estimation of the couple of parameters Bo and k . • The thermo-alkali treatment improved the biomethane potential by 70.1 %; • The raw secondary sludge is slowly biodegradable (k =0.09 d -1 ) but the thermo-alkali treatment increased the hydrolysis constant by 447%;

HERAKLION 2019 International Conference on Sustainable Solid Waste Management 26 – 29 June 2019 Application of semi-continuous pilot-scale AD tests to assess biochemical methane potential and hydrolysis rate constant of raw and pre- treated sludge Thank you for your attention! G. Campo 1 , A.Cerutti 1 , M.C. Zanetti 1 , G. Scibilia 2 , E. Lorenzi 2 , B. Ruffjno 1 giuseppe.campo@polito.it http://www.wearwe.polito.it 1 Department Environment, Land and Infrastructure Engineering, Politecnico di T orino, 10129, T orino, Italy 2 Research Center, Società Metropolitana Acque T orino S.p.A., Viale Maestri del Lavoro, 4 – 10127 T orino, Italy