Research Article
Performance Optimization of Chemical and Green Coagulants in Tannery Wastewater Treatment: A Response Surface Methodology Approach
Table 5
Analysis of variance for response surface model of %COD removal (
), %TSS removal (
), and SVI (
) with cassava starch and orange peel powder coagulants.
| Term | d.f | Cassava starch | Orange peel powder | F-value | value | F-value | value | | | | | | | | | | | | |
| Model | 5 | 12.3 | 10.1 | 223 | 0.002 | 0.004 | ≤0.001 | 15.5 | 17.4 | 1288 | ≤0.001 | ≤0.001 | ≤0.001 | | 1 | 46.4 | 0.22 | 64.9 | ≤0.001 | 0.653 | ≤0.001 | 16.9 | 0.94 | 4085 | 0.005 | 0.365 | ≤0.001 | | 1 | 3.15 | 43.6 | 308 | 0.119 | ≤0.001 | ≤0.001 | 1.68 | 25.1 | 918 | 0.237 | 0.002 | ≤0.001 | | 1 | 7.28 | 0.49 | 209 | 0.031 | 0.505 | <0.001 | 51.1 | 1.06 | 1336 | ≤0.001 | 0.337 | ≤0.001 | | 1 | 2.99 | 6.44 | 26.1 | 0.127 | 0.039 | ≤0.001 | 4.34 | 14.2 | 11.6 | 0.076 | 0.007 | 0.011 | | 1 | 0.06 | 0.10 | 523 | 0.821 | 0.760 | ≤0.001 | 6.65 | 46.4 | 97.5 | 0.037 | ≤0.001 | ≤0.001 | Lack-of-fit | 3 | 3.31 | 1.21 | 1.96 | 0.139 | 0.413 | 0.262 | 2.36 | 2.46 | 1.31 | 0.213 | 0.202 | 0.388 |
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