From: Using the properties of soil to speed up the start-up process, enhance process stability, and improve the methane content and yield of solid-state anaerobic digestion of alkaline-pretreated poplar processing residues
Control
5 : 1
2.5 : 1
1 : 1
Pretreatment
18 ± 3
18 ± 2
16 ± 2
No pretreatment
20 ± 2
18 ± 1
18 ± 4
20 ± 1