Characterization of biochars produced from oil palm and rice husks and their adsorption capacities for heavy metals|
Samsuri, A. W.; Sadegh-Zadeh, F. & Seh-Bardan, B. J.
The objectives of this study were to determine
the selected physicochemical properties of two biochars,
one commercially produced from rice husks and the other
from oil palm empty fruit bunches, and to evaluate their
adsorption capacities for Zn, Cu, and Pb using a batch
equilibrium method. The results showed that there was no
significant difference between the carbon content of biochars
formed from empty fruit bunches (EFBB) and rice
husks (RHB). However, the EFBB did present higher
quantities of O, H, S, N, and K, compared to the RHB.
Although the EFBB had a much lower surface area than the
RHB, the former adsorbed much more Zn, Cu, and Pb than
the RHB. The higher adsorption capacity of the EFBB over
the RHB was a result of the EFBB having higher amounts of
oxygen-containing functional groups, a higher molar ratio of
O/C, and a higher polarity index [(O+N)/C]. This suggests
that the biochar’s chemical properties were more important
than its surface area in the adsorption of Zn, Cu, and Pb.
Heavy metals; Adsorption; Functional groups; Surface area