Table 4 BBD for the optimization of the COD removal of the RSOW treated with T. fermentans
A Coding and levels of experiment factors | ||||
|---|---|---|---|---|
Factor | Symbol | Code level | ||
− 1 | 0 | 1 | ||
Temperature (°C) | X 1 | 20 | 25 | 30 |
Initial pH value | X 2 | 5 | 7 | 9 |
Inoculum concentration (% v/v) | X 3 | 2 | 5 | 8 |
B Box–Behnken design arrangement and responses | ||||
|---|---|---|---|---|
Run | X 1 | X 2 | X 30 | COD removal (%) |
1 | − 1 | 1 | 0 | 49.01 |
2 | 0 | 0 | 0 | 90.12 |
3 | 0 | − 1 | 1 | 87.16 |
4 | 1 | 0 | 1 | 92.49 |
5 | 0 | 0 | 0 | 90.26 |
6 | 0 | 0 | 0 | 91.57 |
7 | 0 | − 1 | − 1 | 86.71 |
8 | 1 | 0 | − 1 | 85.23 |
9 | 0 | 1 | − 1 | 45.45 |
10 | 0 | 1 | 1 | 50.99 |
11 | − 1 | − 1 | 0 | 85.92 |
12 | 0 | 0 | 0 | 91.83 |
13 | − 1 | 0 | 1 | 88.05 |
14 | − 1 | 0 | − 1 | 83.52 |
15 | 0 | 0 | 0 | 91.24 |
16 | 1 | − 1 | 0 | 88.54 |
17 | 1 | 1 | 0 | 51.17 |