Table 6.

Analysis of variance for the quadratic polynomial model for removal of MG and AO.

Source	DF	MG				AO
		Sum of squares	Mean square	F-value	P-value	Sum of squares	Mean square	F-value	P-value
Model	20	12,040.00	602.00	329.35	< 0.0001	10,570.00	528.50	473.63	< 0.0001
A	1	1637.13	1637.13	895.65	< 0.0001	2399.00	2399.00	2149.93	< 0.0001
B	1	1585.03	1585.03	867.14	< 0.0001	2325.98	2325.98	2084.49	< 0.0001
C	1	1095.12	1095.12	599.12	< 0.0001	412.43	412.43	369.61	< 0.0001
D	1	1529.29	1529.29	836.65	< 0.0001	1019.34	1019.34	913.51	< 0.0001
E	1	989.19	989.19	541.17	< 0.0001	327.60	327.60	293.59	< 0.0001
AB	1	53.95	53.95	29.51	0.0002	98.75	98.75	88.50	< 0.0001
AC	1	0.20	0.20	0.11	0.7482	28.60	28.60	25.63	0.0004
AD	1	73.62	73.62	40.27	< 0.0001	27.80	27.80	24.91	0.0004
AE	1	127.24	127.24	69.61	< 0.0001	12.87	12.87	11.53	0.0060
BC	1	26.68	26.68	14.59	0.0028	103.07	103.07	92.37	< 0.0001
BD	1	692.74	692.74	378.99	< 0.0001	7.52	7.52	6.74	0.0249
BE	1	542.42	542.42	296.75	< 0.0001	30.61	30.61	27.43	0.0003
CD	1	69.89	69.89	38.24	< 0.0001	31.39	31.39	28.13	0.0003
CE	1	101.40	101.40	55.48	< 0.0001	303.89	303.89	272.34	< 0.0001
DE	1	230.28	230.28	125.98	< 0.0001	66.14	66.14	59.27	< 0.0001
A2	1	243.48	243.48	133.20	< 0.0001	1110.81	1110.81	995.48	< 0.0001
B2	1	2410.32	2410.32	1318.65	< 0.0001	2090.76	2090.76	1873.69	< 0.0001
C2	1	247.93	247.93	135.64	< 0.0001	177.15	177.15	158.76	< 0.0001
D2	1	862.43	862.43	471.82	< 0.0001	580.22	580.22	519.98	< 0.0001
E2	1	217.58	217.58	119.04	< 0.0001	201.74	201.74	180.79	< 0.0001
Residual	11	20.11	1.83			12.27	1.12
lack of fit	6	7.09	1.18	0.45	0.8180	4.29	0.71	0.45	0.8222
Pure error	5	13.02	2.60			7.99	1.60
Cor total	31	12,060.11				10,582.28

Model summary statistics
MG				AO
R2	Adj-R2	Pred-R2	Adequate precision	R2	Adj-R2	Pred-R2	Adequate precision
0.9983	0.9953	0.9832	65.69	0.9988	0.9967	0.9882	70.19

A: adsorbent dosage (mg), B: pH of the solution, C: MG concentration (mg L⁻¹), D: AO concentration (mg L⁻¹) and E: sonication time (min).