Table 1.
Decolorization of RBBR Determined by Three-factor and Three-level Experiments.
| Treat No. | Temperature (°C) | pH | Dye Concentration (ppm) | Decolorization Percentage (%) |
|---|---|---|---|---|
| 1 | 25 | 4.0 | 100 | 39.20 ± 0.34 d |
| 2 | 25 | 4.5 | 150 | 44.00 ± 0.85 c |
| 3 | 25 | 5.0 | 200 | 35.41 ± 0.08 e |
| 4 | 30 | 4.0 | 150 | 47.65 ± 0.84 b |
| 5 | 30 | 4.5 | 200 | 49.95 ± 0.86 a |
| 6 | 30 | 5.0 | 100 | 26.78 ± 1.00 f |
| 7 | 35 | 4.0 | 200 | 50.34 ± 0.30 a |
| 8 | 35 | 4.5 | 100 | 40.88 ± 0.58 d |
| 9 | 35 | 5.0 | 150 | 45.49 ± 1.23 bc |
The bold font is the optimal decolorization condition. Different letters (a, b, c, d, e, f) indicate statistically significant differences between groups according to one-way ANOVA (n = 3, p < 0.05; refer in-text for test specifics and test statistics).