Constructed rapid infiltration (CRI) system is one type of land-treatment technologies. The characteristics of CRI system are high hydraulic loading and less land area, which is stemmed from the applicability of fast infiltration media replaced the natural soil. From previous experiment, it concludes that the low nitrogen removal rate counteracted CRI system run. This article emphatically discusses the nitrogen removal performance of CRI system with the factors of the wet/dry ratio, hydraulic loa...