It is focused on nitrogen removal and spacial distribution of enzymes in soil matrix.The results showed that: ①under 0.01m3·m-2·d-1 of hydraulic loading rate,nitrogenous and phosphorus substances were removed effectively with COD,NH3-N,TN and TP removals being greater than 90%;②a significant positive relationship could be found between the urease activities at middle or bottom layer and TN removal rate.Besides,a significant negative relationship existed between the nitrite-reductase(NIR) activity at bottom ...