Table 3.

Parameters of modified Gompertz model fitting experimental data

Bottles	Measured CH4 yield, mL CH4/g VS	Calculated values from the model
		CH4 yield, mL CH4/g VS	max CH4 rate, mL CH4/g VS/day	Lag phase, day	R 2a	RMSEa
Untreated + 0%	81 ± 7	79 ± 6	4.2 ± 1	2.20 ± 0.66	0.9892	3.52
Pretreated + 0%	179 ± 7	177 ± 6	9.9 ± 2	8.00 ± 0.32	0.9899	8.11
Pretreated + 2%	197 ± 9	197 ± 8	15.5 ± 3	8.19 ± 1.14	0.9896	9.52
Pretreated + 5%	196 ± 5	196 ± 5	13.3 ± 4	7.25 ± 2.05	0.9902	8.89
Pretreated + 10%	189 ± 2	189 ± 2	13.2 ± 2	6.47 ± 1.22	0.9896	8.87
Pretreated + 15%	188 ± 8	188 ± 7	13.9 ± 2	7.26 ± 0.72	0.9878	9.66

^aR² and RMSE were calculated from the average values of the measured methane production during 50 days and the one calculated using the model