SUPPLEMENTARY DATA

Table I. Characterisation of the pure substrates mono- and co-digestion BMP assays

BMP composition

(mixture in VS-basis)

Mixture in

wet-basis (%)

(Ch/Pr/Li)

Mixture in

TS-basis (%)

(Ch/Pr/Li)

Mixture in

COD-basis (%)

(Ch/Pr/Li)

Initial TS conc.

(g TS L-1)

Initial VS conc.

(g VS L-1)

Initial COD conc.

(g CODt L-1)

Cellulose (Ch) 100/0/0 100/0/0 100/0/0 4.8 4.8 5.2

Casein (Pr) 0/100/0 0/100/0 0/100/0 4.9 4.8 7.4

Olive oil (Li) 0/0/100 0/0/100 0/0/100 4.8 4.8 13.9

50%Ch-50%Pr 50/50/0 50/50/0 41/59/0 4.9 4.8 6.2

50%Pr-50%Li 0/52/48 0/52/48 0/37/63 4.9 4.8 10.7

50%Ch-50%Li 52/0/48 52/0/48 29/0/71 4.8 4.8 9.5

33%Ch-33%Pr-33%Li 34/34/32 34/34/32 20/29/51 4.9 4.8 8.9

66%Ch-17%Pr-17%Li 67/17/16 67/17/16 51/18/31 4.8 4.8 7.5

17%Ch-66%Pr-17%Li 17/67/16 17/67/16 11/62/27 4.9 4.8 8.2

17%Ch-17%Pr-66%Li 18/18/64 18/18/64 8/12/80 4.8 4.8 11.5

Table II. Characterisation of the slaughterhouse waste mono- and co-digestion BMP assays

BMP composition

(mixture in VS-basis)

Mixture in

wet-basis (%)

(Ch/Pr/Li)

Mixture in

TS-basis (%)

(Ch/Pr/Li)

Mixture in

COD-basis (%)

(Ch/Pr/Li)

Initial TS

conc. (g TS L-1)

Initial VS conc.

(g VS L-1)

Initial COD conc.

(g CODt L-1)

Cellulose (Ch) 100/0/0 100/0/0 100/0/0 6.3 5.7 5.7

Casein (Pr) 0/100/0 0/100/0 0/100/0 6.2 5.9 8.7

Olive oil (Li) 0/0/100 0/0/100 0/0/100 6.0 5.9 17.7

50%Ch-50%Pr 63/37/0 51/49/0 40/60/0 6.3 5.8 7.3

50%Pr-50%Li 0/67/33 0/51/49 0/33/67 6.1 5.9 13.2

50%Ch-50%Li 77/0/33 52/0/48 25/0/75 6.4 5.9 12.0

33%Ch-33%Pr-33%Li 53/31/16 35/33/32 18/27/55 6.2 5.8 10.7

66%Ch-17%Pr-17%Li 82/12/6 68/16/16 47/18/35 6.1 5.8 8.0

17%Ch-66%Pr-17%Li 27/65/8 17/67/16 10/60/30 6.1 5.8 9.6

17%Ch-17%Pr-66%Li 36/21/43 18/17/65 7/10/83 5.9 5.8 13.6

Table III. Characterisation of the pure substrates

Parameter Units Cellulose Casein Olive oil

TS g kg-1 918 946 1000

VS g kg-1 915 913 1000

CODt g O2 kg-1 976 1401 2890

Table IV. Characterisation of the slaughterhouse wastes

Parameter Units Paunch Blood DAF sludge

TS g kg-1 117 187 360

VS g kg-1 106 178 353

CODt g O2 kg-1 106 266 1053

CODs g O2 kg-1 2.5 253 3.7

VFA g kg-1 0.64 1.86 0.52

- Acetic acid g kg-1 0.36 1.47 0.22

- Propionic acid g kg-1 0.18 0.19 0.27

- Butyric acid g kg-1 0.08 0.15 0.01

- Valeric acid g kg-1 0.03 0.05 0.02

Ethanol g kg-1 0.02 0.14 0.06

Oil and grease g kg-1 4.5 1.5 265

Total proteins g kg-1 10.2 129.5 11.8

Soluble proteins g kg-1 1.7 128.2 0.4

Total carbohydrates g kg-1 55.5 3.7 0.6

Soluble carbohydrates g kg-1 1.6 0.1 0.4

TKN g kg-1 0.60 26.7 1.2

TKP g kg-1 0.21 0.20 0.29

Chloride mg kg-1 147 2617 84

Ammonium mg N kg-1 143 391 49

Nitrite mg N kg-1 0.2 1.1 0.5

Nitrate mg N kg-1 0.05 0.97 0.01

Phosphate mg P kg-1 161 164 162

Sulphate mg S kg-1 9.3 38 19

Aluminium mg g-1 TS 0.86 n.d.* n.d.

Calcium mg g-1 TS 4.09 n.d. 7.48

Iron mg g-1 TS 0.84 0.25 0.29

Lead mg g-1 TS 0.003 0.004 0.011

Magnesium mg g-1 TS 0.46 n.d. n.d.

Phosphor mg g-1 TS 2.13 0.13 2.53

Potassium mg g-1 TS 1.39 n.d. 0.19

Silicium mg g-1 TS 0.24 0.001 0.20

Zinc mg g-1 TS 0.02 n.d. 0.01

*n.d. non-detected (< 0.001 mg g-1 TS)

Table V. Model parameters for pure substrates mono- and co-digestion (experimental versus simulation results at Fig. II and III of supplementary data)

fch* fpr

** fli*** khyd,ch khyd,pr khyd,li KI,li tdelay BMP composition

- - - day-1 day-1 day-1 g VS L-1 day

Single set of parameters for all BMPs

0.91±0.04 0.80±0.01 0.86±0.02 0.23±0.04 0.60±0.08 0.64±0.11 1.17±0.23 0.88±0.16

Parameters when each BMP had a different KI li and tdelay

0.90±0.02 0.81±0.01 0.85±0.01 0.23±0.02 0.44±0.05 0.61±0.06 ˅ ˅ < Common values

- 1.59±0.11 Cellulose (Ch)

- 0.95±0.11 Casein (Pr)

1.93±0.17 4.08±0.10 Olive oil (Li)

- 0.43±0.11 50%Ch-50%Pr

1.10±0.16 0.24±0.09 50%Pr-50%Li

1.17±0.16 1.00±0.11 50%Ch-50%Li

1.46±0.17 0.45±0.10 33%Ch-33%Pr-33%Li

2.56±0.15 1.09±0.10 66%Ch-17%Pr-17%Li

1.66±0.17 0.49±0.10 17%Ch-66%Pr-17%Li

1.33±0.16 1.23±0.11 17%Ch-17%Pr-66%Li

* Cellulose B0/f conversion factor is 373 mL CH4 g-1 VS

** Casein B0/f conversion factor is 537 mL CH4 g-1 VS

*** Olive oil B0/f conversion factor is 1012 mL CH4 g-1 VS

Table VI. Model parameters for slaughterhouse waste mono- and co-digestion (experimental versus simulation results at Fig. IV and V of supplementary data)

fch fpr fli khyd,ch khyd,pr khyd,li KI,li tdelay BMP composition

- - - day-1 day-1 day-1 g VS L-1 day

Single set of parameters for all BMPs

0.71 ± 0.07 0.76 ± 0.02 0.91 ± 0.02 0.11 ± 0.04 0.70 ± 0.10 0.80 ± 0.20 1.27 ± 0.34 0.66 ± 0.19

Parameters when each BMP had a different fch, fli, KI li and tdelay

0.77 ± 0.01 0.12 ± 0.02 0.35 ± 0.06 1.04 ± 0.12 ˅ ˅ < Common values

0.63 ± 0.04 - - 1.91 ± 0.09 Paunch (Ch)

- - - 0.45 ± 0.09 Blood (Pr)

- 0.82 ± 0.01 1.27 ± 0.18 4.37 ± 0.09 DAF sludge (Li)

0.71 ± 0.04 - - 0.21 ± 0.08 50%Ch-50%Pr

- 0.83 ± 0.01 1.58 ± 0.20 0.86 ± 0.09 50%Pr-50%Li

0.59 ± 0.03 0.99 ± 0.01 1.33 ± 0.19 1.99 ± 0.08 50%Ch-50%Li

0.71 ± 0.04 0.82 ± 0.01 1.19 ± 0.19 0.49 ± 0.09 33%Ch-33%Pr-33%Li

0.59 ± 0.03 0.99 ± 0.01 0.74 ± 0.20 0.39 ± 0.09 66%Ch-17%Pr-17%Li

0.70 ± 0.04 0.99 ± 0.01 1.07 ± 0.19 0.32 ± 0.09 17%Ch-66%Pr-17%Li

0.62 ± 0.04 0.99 ± 0.01 1.46 ± 0.19 1.39 ± 0.09 17%Ch-17%Pr-66%Li

* Paunch B0/f conversion factor is 350 mL CH4 g-1 VS

** Blood B0/f conversion factor is 523 mL CH4 g-1 VS

*** DAF sludge B0/f conversion factor is 1050 mL CH4 g-1 VS

 

Fig. I. Comparative of the cumulative methane production of pure and slaughterhouse substrate mono-digestion assays; cellulose (■), casein (●), olive oil (▲), paunch (□), blood (○), and DAF sludge (∆)

Cellulose  Casein 

   Olive oil  50% Ch - 50% Pr 

   

50% Pr - 50% Li  50% Ch - 50% Li 

   33% Ch – 33% Pr - 33% Li  66% Ch – 17% Pr - 17% Li 

   

17% Ch – 66% Pr - 17% Li  17% Ch – 17% Pr - 66% Li 

   

Fig. II. Cumulative methane production in the course of time of pure substrates when the 10 BMPs were simulated with a single set of parameters: cellulose (■), casein (▲), olive oil (●) and mixtures (×) and modelled profile of the mixture (solid line).

Cellulose  Casein 

 Olive oil  50% Ch - 50% Pr 

   50% Pr - 50% Li  50% Ch - 50% Li 

33% Ch – 33% Pr - 33% Li  66% Ch – 17% Pr - 17% Li 

   

17% Ch – 66% Pr - 17% Li  17% Ch – 17% Pr - 66% Li 

 

Fig. III. Cumulative methane production in the course of time of pure substrates when some variables (KI,li and tdelay) were different for each BMP: cellulose (■), casein (▲), olive oil (●) and mixtures (×) and modelled profile of the mixture (solid line).

Paunch  Blood 

   DAF sludge  50% Ch - 50% Pr 

   50% Pr - 50% Li  50% Ch - 50% Li 

   33% Ch – 33% Pr - 33% Li  66% Ch – 17% Pr - 17% Li 

   

17% Ch – 66% Pr - 17% Li  17% Ch – 17% Pr - 66% Li 

   

Fig. IV. Cumulative methane production in the course of time of SHW when the 10 BMPs were simulated with a single set of parameters: paunch (□), blood (∆), DAF sludge (○) and mixtures (×) and modelled profile of the mixture (solid line).

Paunch  Blood 

 DAF sludge  50% Ch - 50% Pr 

   50% Pr - 50% Li  50% Ch - 50% Li 

   33% Ch – 33% Pr - 33% Li  66% Ch – 17% Pr - 17% Li 

   

17% Ch – 66% Pr - 17% Li  17% Ch – 17% Pr - 66% Li 

   

Fig. V. Cumulative methane production in the course of time of when some variables (fch, fli

KI,li and tdelay) were different for each BMP: paunch (□), blood (∆), DAF sludge (○) and mixtures (×) and modelled profile of the mixture (solid line).