Table 1.

Economic analysis of different processes in methane production and VS reduction.

Parameters		AD performance (CNY/L CH4)	VS reduction (CNY/g VS)
Ozonation (mmol O3/g VS)	0.1	0.38	0.08
	0.3	1.04	0.21
	0.5	1.46	0.33
Fe2+-S2O82−(mmol S2O82−/g VS)	0.1		0.03
	0.3		0.10
	0.5		0.22
F/T (cycle)	1	0.19	0.06

∗Gray area indicates the methane production in the pretreated sample was lower than that in the raw sludge.