968692.fig.004a
(a)
968692.fig.004b
(b)
968692.fig.004c
(c)
Figure 4: Ratio of volatile fatty acids to alkalinity for each pretreatment of rice straw. (a) 4% Ca(OH)2 pretreatment; (b) 8% Ca(OH)2 pretreatment; (c) 12% Ca(OH)2 pretreatment.