Batch experiments using sediment mud liquors spiked with 17β estradiol (E2) were performed. The sediment mud liquors were prepared from the sliced surface (SL

0~2 cm)

middle (ML

14~16 cm) and bottom (BL

28~30 cm) layers of sediment cores collected in a lake

respectively. By measuring the concentration profiles of E2 and its biotransformation compound

estrone (E1)

the great dependency of E2’s degradation behavior upon the vertical position of the sediment and temperature was clearly demonstrated under both aerobic and anaerobic conditions: the degradation rate decreased with the increase of sediment depth and increased with higher temperature. In addition

by assuming a first order rate reaction

the disappearance rate constant (k) of E2 under the aerobic condition was estimated to in the range of 0002~0.120 h-1·g-1·L

while under the anaerobic condition in the range of 0.002~0.057 h-1·g-1·L. Because of microorganism domestication and competition reduction of organic compounds

k was increased by about 34% after re spiking E2. The addition of ammonia to the experiment under aerobic condition seemed to be responsible for promoting disappearance of E2 from solutions.