Batch tests were carried out to investigate the COD degradation of landfill leachate by using a moving-bed bioreactor (MBBR)，and a modified bio-kinetic model was established to describe the biological reaction.The experimental results showed that the model could describe the biodegradation of leachate

and the kinetic parameter K2 could be used as indicator of degradation rate and Sn could be used to estimate the biodegradability of leachate.The simulations under different initial leachate concentrations found that K2 and Sn were linear to the initial leachate concentration S0.The data of different bio-carrier volumes also perfectly conformed to the model and further proved that the kinetic parameters in the model were independent of the biomass.The continuous operation of two MBBR in series could effectively remove the landfill leachate

when the total hydraulic retention time(HRT)was 4 d，the average COD removal efficiency was 89.24% and the effluent COD was about 452.10 mg·L-1

which was similar to the predicted value by the model under the same initial concentration.The performance of two MBBR in series gave a direct proof of the reliability of the model that was used to estimate the biodegradability of leachate.