Screening of factors that influence the preparation of Dialium guineense pods active carbon for use in methylene blue adsorption: a full factorial experimental design

Bulletin of the National Research Centre

Table 3 ANOVA for the yield and adsorption capacity of DGPAC

Source	DF	Adj SS	Adj MS	F-value	P-value
Yield of DGPAC
Model	3	406.78	135.595	30.45	0.001
A: [Activating agent]	1	292.58	292.578	65.71	0.000
B: Activation time (min)	1	85.02	85.021	19.09	0.005
AB	1	29.18	29.185	6.55	0.043
Curvature	1	11.69	11.686	3.89	0.106
Error	6	26.72	4.453
Total	9	433.50
S: 2.11010, R²: 93.84%, R²(adj): 90.76%, R²(pred): 86.11%

Source	DF	Adj SS	Adj MS	F-value	P-value
Adsorption capacity of DGPAC for methylene blue
Model	7	71.5369	10.2196	1493.55	0.001
A: [Activating agent]	1	45.5371	45.5371	6655.07	< 0.001
B: Activation time (min)	1	0.0241	0.0241	3.52	0.202
C: Activating agent	1	13.3789	13.3789	1955.27	0.001
AB	1	1.6247	1.6247	237.44	0.004
AC	1	2.1878	2.1878	319.74	0.003
BC	1	0.9438	0.9438	137.93	0.007
Curvature	1	7.8406	7.8406	1145.87	0.001
Error	2	0.0137	0.0068
Total	9	71.5506
S: 0.0827193, R²: 99.98%, R²(adj): 99.91%, R²(pred): 99.72%

DF, degrees of freedom; Adj.SS, adjusted sum of squares; Adj MS, adjusted mean of squares; F-value, Fisher’s test value; P-value, probability value