2.2. Pretreatment of corncob
Corncob was pretreated by the different methods described in
Fig. 1.
2.2.1. Soaking in aqueous ammonia (SAA)
Oven-dried corncob was placed in a screw-capped laboratory
bottle (Pyrex glass) and then mixed with 15 wt% aqueous ammonia
at a ratio of 1 g solid per 6 mL liquid. The solid/liquid slurry was
incubated in a water bath at 60 C for 12 h, with no agitation. After
SAA, the solids were separated by filtering and washed with distilled
water until neutral pH was attained. The solid residue was
dried in a forced-air oven at 105 C.