The elemental composition, iodine value and methylene blue
value of the adsorbents are shown in Table 1.
Both the iodine value and the methylene blue value of B–SBA–K
were much higher than those of SBA. Though the iodine value of
Acid-B–SBA–K was lower than that of B–SBA–K, it was still beyond
the value of SBA. Besides, the methylene blue value of Acid-B–SBA–
K was twice that of SBA. These changes can be explained by the
pyrolysis activation and HNO3 oxidation. The surface of Acid-B–
SBA–K had been changed in both pore diameter and special func-
tional group due to HNO3 oxidation, which made Acid-B–SBA–K
totally different from B–SBA–K.