Abstract:To effectively improve the C/N and increase the biodegradability of the landfill leachate, fly ash was chosen as sorbent to treating ammonia-nitrogen in leachate. The effect of dosage, temperature and pH on adsorption of NH3-N onto fly ash were separately studied, kinetics analysis was used for the adsorption process in the optimum adsorption conditions. Experiment results showed that fly ash had the better adsorption ability of treating ammonia-nitrogen in leachate, the adsorption equilibrium time was 180min, then the removal rate of ammonia-nitrogen was 63.44%, the equilibrium adsorption capacity was 8.7428mg/g. Linearizations of the different kinetic equations showed that adsorption process in line with the pseudo-secondary kinetic equation; Moving boundary model analysis showed that the adsorption rate of ammonia-nitrogen was mainly governed by liquid film diffusion; With the linearization of Dünwald-Wagner formula, estimated the effective diffusion coefficient(Dc) was 3.058×10-9cm2/s.