Abstract: Tea plant (Camellia sinensis L) was employed as a model plant to study fluoride (F) uptake kinetic using both the general depletion and modified depletion methods. General depletion was the method that put the tea into solution of a initial F concentration of 0.1 mg/L, 0.2 mg/L, 0.6 mg/L and sampled 2 ml of the solution every 12 h until 84 h. The absorptive quantity was calculated by the difference of F concentration. Modified depletion was the method that put the tea into solution of an initial F concentration of 0.1 mg/L, 0.2 mg/L, 0.4 mg/L, 0.6 mg/L, 0.8 mg/L, 1 mg/L, 2 mg/L and sampled 2 ml of the solution after 24 h. The absorptive rate was calculated by the difference of F concentration. The results on the kinetic parameter by using of the general depletion were different from those by using the modified depletion method. It is because of the initial F concentration. The modified depletion method was a preferable method and the parameters were much reasonable by using of the plotting method and Sigma Plot than the other method. Result showed that the method V_max was 2.605(µg/g*h DW) and 3.419(µg/g*h DW), and K_m was 0.385 mg/L and 0.541 mg/L respectively.

Key words: tea, fluoride, uptake kinetics, depletion