The washed and dried rice husks were submitted to
dierent types of chemical treatment. Acid leaching was erformed by reflux boiling in 3% (v/v) HCl and 10%
(v/v) H2SO4 for 2 h, at a ratio of 50 g husk/l. Alkaline
leaching used a 3% (v/v) NaOH solution for 24 h at
room temperature (approx. 25C), at a ratio of 50 g
husk/l. After leaching, the husk was thoroughly washed
with distilled water and then dried in an air oven at
110C.