| Item | SS Reduction (%) | VSS Reduction (%) | Growth rate of earthworm weight (%) | Increase rate of earthworm density (%) | Increase rate of earthworm biomass (%) | Filter’s maximum sludge capability (g/L) |
| R3 | 34.95 | 43.01 | 25.56 | 5.65 | 35.65 | 10.95 |
| R4 | 45.21 | 53.89 | 32.21 | 6.59 | 44.11 | 10.18 |
| Variation ratio | 29.36% | 25.30% | 25.78% | 17.86% | 23.53% | −7.03% |
| Effect | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ |