DESIGN AND OPTIMIZATION FOR HAZARDOUS JAROSITE WASTE RECYCLING IN ENVIRONMENTALLY SUITABLE COMPOSITE PRODUCTS USING RESPONSE SURFACE METHODOLOGY - Management of Hazardous Residues Containing Cd - page 73

Table 16. Lack of fit test for response water absorption

Source Sum of

Squares

DF Mean

Square

F Value Proc>F

Linear 8.67 7 1.24 3.66 0.1135

Quadratic 0.99 4 0.25 0.73 0.6151

Special Cubic 0.33 3 0.11 0.32 0.8104

Cubic 0.000 0

Pure Error 1.35 4 0.34

Table 17. Lack of fit test for response shrinkage

Source Sum of

Squares

DF Mean

Square

F Value Proc>F

Linear 448.49 7 64.07 98.00 0.0003

Quadratic 73.52 4 18.38 28.11 0.0035

Special Cubic 20.50 3 6.83 10.45 0.0231

Cubic 0.000 0

Pure Error 2.62 4 0.65

Table 18. Lack of fit test for response brick density

Source Sum of

Squares

DF Mean

Square

F Value Proc>F

Linear 0.054 7 7.671E-003 9.30 0.0239

Quadratic 1.849E-003 4 4.624E-004 0.56 0.7057

Special Cubic 1.768E-003 3 5.893E-004 0.71 0.5927

Cubic 0.000 0

Pure Error 3.300E-003 4 8.250E-004

Table 19. Lack of fit test for response Lead

Source Sum of

Squares

DF Mean

Square

F Value Prob > F

Mean 268.34 1 268.34

Linear 248.60 2 124.30 11.43 0.0021

Special Cubic 4.45 1 4.45 1.41 0.2742 suggested

Residual 0.019 4 4.728E-

003

Total 636.53 14 45.47