Table 3 The variance analysis of the fitting model.

From: Optimization pilot scale study on ammonia nitrogen removal by bio filter

Source

Sum of squares

DF

Mean square

F value

P value

Model

3110.26

9

345.58

45.00

 < 0.0001

X1

141.90

1

141.90

18.48

0.0016

X2

945.73

1

945.73

123.15

 < 0.0001

X3

3.56

1

3.56

0.46

0.5113

X1·X2

6.72

1

6.72

0.87

0.3717

X1·X3

37.95

1

37.95

4.94

0.0404

X2·X3

18.69

1

18.69

2.43

0.1498

X12

1024.40

1

1024.40

133.40

 < 0.0001

X22

879.00

1

879.00

114.46

 < 0.0001

X32

415.75

1

415.75

54.14

 < 0.0001

Residual

76.79

10

7.68

  

Lack of fit

62.37

5

12.47

4.32

0.0670

Pure error

14.43

5

2.89

  

Cor total

3187.05

19