Abstract:District, Langfang City, a combined process of zeolite biological filter and sponge iron/limestone filterwas constructed. The removal of COD and TP by the combined process and the optimal operation pa⁃rameters were investigated. The results show that the sponge iron/limestone filter is homogeneouslyfilled, and the volume ratio of sponge iron/limestone is 3 ∶ 7.With an influent COD concentration of 72± 11 mg/L, an influent TP concentraiton of 1.52 ± 0.53 mg / L, and HRT of 1.5 h, the average re⁃moval rates of COD and TP are 76.51% and 85.37%, respectively, by the combined process. Whenthe combined process was under the normal water quality conditions (COD=56 ± 10 mg/L, TP=0.65± 14 mg/L) and the HRT was 0.8 h, the average removal rates of COD and TP are 89.33% and 74.27%,and the effluent COD and TP concentrations meet the class IV water standard of surface water. Close-