df Sum of Square Mean Square F-value P-value
PFS Regression 5 45.141 9.028 9.85 0.005
Total error 7 6.414 0.916    
Lack of fit 3 3.032 1.011 1.20 0.418
Pure error 4 3.381 0.845    
PFPD1 Regression 5 61.019 12.204 18.45 0.001
Total error 7 4.630 0.6614    
Lack of fit 3 2.717 0.906 1.89 0.272
Pure error 4 1.913 0.478    
PFPD2 Regression 5 234.890 46.978 13.68 0.002
Total error 7 24.040 3.434    
Lack of fit 3 16.537 5.512 2.94 0.162
Pure error 4 7.503 1.876    
PFPD3 Regression 5 238.020 47.604 43.68 0.000
Total error 7 7.628 1.090    
Lack of fit 3 6.041 2.014 5.07 0.075
Pure error 4 1.587 0397    
Table 6: ANOVA results for COD removal efficiency.