|   指标  |       
  |       C  |       F4  |       F8  |       F12  |       F16  |       F20  |       F24  |    
|   初始值 (mg·L−1)  |       N  |       1.65 ± 0.13  |       1.65 ± 0.13  |       1.65 ± 0.13  |       1.65 ± 0.13  |       1.65 ± 0.13  |       1.65 ± 0.13  |       1.65 ± 0.13  |    
|   P  |       0.14 ± 0.02  |       0.14 ± 0.02  |       0.14 ± 0.02  |       0.14 ± 0.02  |       0.14 ± 0.02  |       0.14 ± 0.02  |       0.14 ± 0.02  |    |
|   末值 (mg·L−1)  |       N  |       9.23 ± 1.41a  |       8.86 ± 1.21a  |       7.33 ± 1.01b  |       6.42 ± 0.98c  |       6.23 ± 1.10c  |       6.03 ± 1.22c  |       6.13 ± 1.41c  |    
|   P  |       0.65 ± 0.04a  |       0.62 ± 0.02a  |       0.53 ± 0.03b  |       0.47 ± 0.05bc  |       0.43 ± 0.02c  |       0.45 ± 0.05c  |       0.40 ± 0.03c  |