Synthesis and Characterisation of Activated Carbon Obtained from Marula (Sclerocarya birrea) Nutshell

Table 2

Yield of activated carbon from H₃PO₄ treatment.

Acid (%)	Temperature (°C)				value
	200	400	500	600
Control	95.8 ± 0.01	NY	NY	NY	ns
20	73.6 ± 0.02^a	38.4 ± 0.02^b	45.1 ± 0.01^b	26.9 ± 0.02^c	<0.05
40	77.0 ± 0.01^a	52.9 ± 0.01^b	67.9 ± 0.01^c	45.8 ± 0.01^b	<0.05
60	68.4 ± 0.01^a	52.8 ± 0.02^b	66.6 ± 0.02^a	60.6 ± 0.02^a	<0.05

 = distilled water, NY = no yield; ns = not significant; mean ± standard deviations are reported. Means in a row with different superscripts (^a,b,c) are significantly different at .