84
AD was from 110 to 120 days. Average biogas yield was 600 L kg
−1
ODM fermented. Some constraints of this technology are the pH value dropping due to the
cumulative total of volatile fatty acids (TVFAs), short-retention time due to accumulated rice straw inside the digester, and limited skill of management that may
cause biogas leaking and environmental harm.
0
100
200
300
400
Soaking in biogas effluent
Soaking in anoxic sediment
Soaking in ditch water
Soaking in tap water
Untreated rice straw
Biogas liquid waste (190 oC, 30 min)
Untreated pretreatment
Fungus (Chaetomium globosporum)
Untreated pretreatment
Methane yield (L.kgVS added )
Biological pre-treatment methods
Fig. 5.6 Biological pretreatment methods of rice straw for biogas production
Fig. 5.7 Continuous farm-scale AD: (a) isometric cut-away view; (b) as practices in Vietnam
N. V. C. Ngan et al.
AD was from 110 to 120 days. Average biogas yield was 600 L kg
−1
ODM fermented. Some constraints of this technology are the pH value dropping due to the
cumulative total of volatile fatty acids (TVFAs), short-retention time due to accumulated rice straw inside the digester, and limited skill of management that may
cause biogas leaking and environmental harm.
0
100
200
300
400
Soaking in biogas effluent
Soaking in anoxic sediment
Soaking in ditch water
Soaking in tap water
Untreated rice straw
Biogas liquid waste (190 oC, 30 min)
Untreated pretreatment
Fungus (Chaetomium globosporum)
Untreated pretreatment
Methane yield (L.kgVS added )
Biological pre-treatment methods
Fig. 5.6 Biological pretreatment methods of rice straw for biogas production
Fig. 5.7 Continuous farm-scale AD: (a) isometric cut-away view; (b) as practices in Vietnam
N. V. C. Ngan et al.