Study On Nitrogen Removal Of Sewage In Rural Area By Integrated Flow Constructed Rapid Infiltration And Ecological Field System

With the rapid development of small towns, the problem of water pollution and water shortage is serious. In order to solve this problem, we carry out a progress to deal with the sewage the by using integrated flows constructed rapid infiltration and ecological field system.This study relys on the Twelfth Five-Year Guideline which is about the small town’s technology development.The study of integrated flows constructed rapid infiltration and ecological field system is basically in the early stages in China, and we should strengthen the basic theory and the optimization of process parameters. This study is mainly about the process operating parameters of the vadose zone and the saturation zone、the factors and strengthening means of denitrification in the Integrated flows constructed rapid infiltration and ecological field system, meanwhile the system’s kinetic and the removing of nitrogen are studied. This study concludes two parts: column reactor test, tank reactor test.The first part of the study is vadose zone reoxygenation in the integrated flows constructed rapid infiltration and ecological field system. It studies the effect of vadose zone of nitrification. The effect factors include the ratio of wet and dry, hydraulic load cycle, spray reoxygenation, layered natural ventilation reoxygenation, plant root complex oxygen. The results shows that the average removal rate increases first and then decreased in the five kinds of wet and dry ratio. The maximum of remove rate of the stratified column reactor (ventilation) is twice to the non-hierarchical ammonia column reactor (no ventilation). Selecting five kinds of hydraulic load cycle,when HLC=6 h, ammonia nitrogen removal rate of column reactor is best. Spray measures can improve dissolved oxygen and strengthen biological nitrification When the flow rate Q=2 L/min and spraying height H=0.2 m, removal rate of ammonia is the best. efficiency. Plant roots can improve the permeability of percolation medium, form oxidized zones near the roots,and improve biological nitrification effect. In the tank reactor testing stage, the influence of denitrification carbon source(maize cob) on is studied.denitrification,mainly including the ability to release carbon in maize cob and the permeability of the saturation zone. The results shows that maize cob is available for denitrification for 89 days. The permeability of top percolation media is better than the middle layer and the low layer. This study also examined the kinetics of denitrification characteristics of groove in the reactor, the results shows that the removal of nitrate nitrogen accord kinetics of reaction, which belongs to the first order reaction.The study of integrated flows constructed rapid infiltration and ecological field system relies on the flooding drying reoxygenation method to reach a steady remove rate of nitrogen. Suitable wet and dry ratio, hydraulic loading cycle, spray reoxygenation, layered filler and ventilation can increase the rate of nitrification in the vadose zone. The treated sewage can reach the first A level of discharge standard on TN.