Statistical Optimization of Operational Parameters for Enhanced Naphthalene Degradation by TiO_𝟐/Fe_𝟑O_𝟒-SiO_𝟐 Photocatalyst

Table 3

Analysis of variance (ANOVA) for the model regression representing degradation rate.

Source	Sum of squares	df	Mean square	F value	P value (Prob > 𝐹)
Model	3557.63	9	395.29	551.40	<0.0001
𝑥1	1707.76	1	1707.76	2382.18	<0.0001
𝑥2	21.57	1	21.57	30.09	0.0004
𝑥3	774.28	1	774.28	1080.06	<0.0001
𝑥1𝑥2	2.49	1	2.49	3.47	0.0955
𝑥1𝑥3	52.33	1	52.33	72.99	<0.0001
𝑥2𝑥3	7.64	1	7.64	10.66	0.0098
𝑥1^2	638.82	1	638.82	891.10	<0.0001
𝑥2^2	197.46	1	197.46	275.44	<0.0001
𝑥3^2	332.13	1	332.13	463.30	<0.0001
Residual	6.45	9	0.72
Lack of fit	5.84	5	1.17	7.64	0.036
Cor total	3565.48	19