The CLFT theory can be used to explain the extended defluorination incubation period in treating 200 µL AFFF. The Z0 of 200 µL AFFF was calculated to be 7.5 µm. According to the exsitu heating tests (Figure ), the volume reduction at 4, 6, and 8 h is projected to be 38, 56, and 75%, corresponding to Z values of 4.6, 3.3, and 1.9 µm, respectively. Only Z of 1.9 μm is less than CLFT, which explains the sharp increase of DeF at 8 h (Figure ).