Meanwhile nitrogen removal and phosphorus removalwere observed in this study. 3) The sludge concentrations of the low, middle and top of the packings were 14876mg/L,4218mg/L and 291mg/L respectively.

• 系统内填料层下部、中部和上部的平均污泥浓度分别为14876mg/L、4218mg/L和291mg/L，生物膜含量从下到上逐渐减少，污泥床污泥已部分颗粒化，形成沉降性能良好的颗粒污泥；