Quality indices of activated carbons from cattle bone (CB), coconut-shell (CS) and wood carbon (WC)
as influenced by mode of activation (heat and acid) were studied using the non-activated carbon
samples as control. Preliminary investigation was carried out to determine optimum condition for
carbonization and activations. The iodine values, ash, bulk densities, moisture, hardness and porosity
analysis of the samples were evaluated using standard methods. Heat (H) activation was at 950°C for 3
h to produce heat activated bone carbon (HCB), and 850°C for 21
/2 h for heat activated coconut-shell
(HCS) and wood carbon (HWC) while concentrated phosphoric acid (1:4) carbon: acid (w/w) was at
600°C for 2 h to produce acid activated wood (AWC), acid activated coconut-shell (ACS) and acid
activated bone (ACB) samples. The activation yield for the acid activation ranged from 40.40 to 46.21%
while heat activation ranged from 36.30 to 41.10%. Iodine values for heat activated carbons ranged from
828.39 (HCB) to 995.38 (HWC) mg/g. That of acid activated carbons ranged from 834.94 (ACB) to 914.17
(AWC) mg/g as compared with 66.2 to 222.7 mg/g for non-activated carbons (controls). Hardness of heat
activated carbons ranged from 88.5 to 93.5% while that of acid activated carbons ranged from 62.0 to
89.5%. Bulk densities ranged from 0.40 to 0.79 g/cm3
. The moisture for heat activated carbons ranged
from 4.7 (HCB) to 8.4% (HWC) while that of acid activated carbons ranged from 5.0 (ACB) to 9.4%
(AWC). The volume activities for the activated carbon samples ranged from 228.7(HCB) to 324.9 (HWC).
The ash for bone carbons ranged from 80.6 to 85.9% while those of coconut shell and wood ranged
from 1.1 to 3.5%. The carbons presented Brunauer, Emmett and Teller (BET) surface areas between 718
and 1018 m
2
/g, and micropores and mesopores with volumes between 0.004 and 0.776 cm3
/g. This study
indicated that efficient activated carbons could be obtained from local raw materials by controlled