| Time (year) | Sample Location | Degradation Dynamics Equation | Correlation Coefficient | Half-Life (d) |
| 2011 | Yangzhou | Ct = 0.1865e−0.1750t | 0.9812 | 3.96 |
| Jingzhou | Ct = 0.1937e−0.1791t | 0.9844 | 3.87 | |
| 2012 | Yangzhou | Ct = 0.2007e−0.1977t | 0.9865 | 3.51 |
| Jingzhou | Ct = 0.2106e−0.2021t | 0.9783 | 3.43 |