Table 4 Results of the analysis of variance (ANOVA) for the response surface quadratic model.
Source | The concentration of H2S | pH | ORP | Utilization of SO42− | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
F-value | p-value | Results | F-value | p-value | Results | F-value | p-value | Results | F-value | p-value | Results | |
Model | 207.34 | < 0.0001 | Significant | 1346.99 | < 0.0001 | Significant | 45.36 | < 0.0001 | Significant | 133.09 | < 0.0001 | Significant |
A | 10.07 | 0.0156 | Significant | 150.68 | < 0.0001 | Significant | 20.45 | 0.0027 | Significant | 24.13 | 0.0017 | Significant |
B | 11.54 | 0.0115 | Significant | 4358.60 | < 0.0001 | Significant | 119.44 | < 0.0001 | Significant | 27.00 | 0.0013 | Significant |
C | 7.43 | 0.0295 | Significant | 35.66 | 0.0006 | Significant | 9.86 | 0.0164 | Significant | 7.51 | 0.0289 | Significant |
AB | 6.08 | 0.0431 | Significant | 1.98 | 0.2021 | Not significant | 10.23 | 0.0151 | Significant | 7.14 | 0.0319 | Significant |
AC | 0.000 | 1.0000 | Not significant | 0.000 | 1.0000 | Not significant | 3.16 | 0.1189 | Not significant | 0.00 | 1.0000 | Not significant |
BC | 0.0025 | 0.9514 | Not significant | 0.88 | 0.3793 | Not significant | 95.47 | < 0.0001 | Significant | 6.44 | 0.0388 | Significant |
A2 | 627.36 | < 0.0001 | Significant | 7565.95 | < 0.0001 | Significant | 33.38 | 0.0007 | Significant | 275.52 | < 0.0001 | Significant |
B2 | 957.84 | < 0.0001 | Significant | 40.99 | 0.0004 | Significant | 85.39 | < 0.0001 | Significant | 562.94 | < 0.0001 | Significant |
C2 | 89.91 | < 0.0001 | Significant | 47.38 | 0.0002 | Significant | 17.12 | 0.0044 | Significant | 177.14 | < 0.0001 | Significant |
Lack of Fit | 5.69 | 0.0632 | Not significant | 1.98 | 0.2593 | Not significant | 5.27 | 0.0711 | Not significant | 4.40 | 0.0931 | Not significant |
R2 | 0.9963 | 0.9994 | 0.9831 | 0.9942 | ||||||||
R2Adj | 0.9915 | 0.9987 | 0.9615 | 0.9867 | ||||||||
