Nitrogen Removal along Vertical direction by Plant Biological Membrane System

Abstract

Based on the equipment of integrated constructed wetlands (ICWs) with independent intellectual property rights. Plant biological membrane system (PBMS) was constructed to purify nitrogen of sanitary sewage. PBMS includes palm silk, non-woven and floating plant (Trifolium repens L.). Total nitrogen (TN), ammonia nitrogen (NH3-N) was investigated to evaluate the effects of the layered purification and resistance to the outside impact. The results showed that layered purification occurred along the flowing vertical direction. The average removal rate of TN, NH3-N and total dissolved solids was 65.6%, 60.7% and 38.7%, respectively. The TN and NH3-N removal load of the lower, middle and upper layer were 1.0, 0.8, 0.7g/ (m2.d) and 0.8, 0.8, 0.3g/ (m2.d), respectively. The higher concentration of inflow the stronger resists impact load capability. The TN and NH3-N average removal load of the lower, middle and upper layer were 4.1, 1.88, 1.57 times and 3.13, 1.25, 1 time than those of the stable phase, respectively.