Relationships Between Loading Rates and Nitrogen Removal Effectiveness in Subsurface Constructed Wetlands
潜流人工湿地负荷变化对脱氮效果的影响研究

About forty kinds of nitrogen loading removal rate were studied in field in 15 months,inflow and outflow loading rules of reeds/Zizania caduciflora/mixing and no-plant bed were discussed in different inflow loading.The four kinds SFS inflow loading changed from 400 mg·(m2·d)-1 to(8000) mg·(m2·d)-1,while outflow loading is less than(7?000) mg·(m2·d)-1.Results show that outflow loading increase with the increase of inflow loading,linear relation is obvious.Total nitrogen removal rate has the same trend at low inflow loading.But in high inflow loading TN removal rate has much variation.The system had better run between(2 000) mg·(m2·d)-1 and(4 000) mg·(m2·d)-1 inflow loading.Average removal rate in between(1 062) mg·(m2·d)-1 and (2 007)(mg·(m2·d)-1).Plant SFS removal rate is better than no-plant SFS.TN removal rate of reed and zizania caduciflora bed is 63% and 27% higher than no-plant bed.Plant harvesting is unimportant and contributes less than 5% of TN removal loading,plant can improve system micro-enviroment and hydrology condition which could increase TN removal rate.The results provided deep insight to SFS nitrogen removal and reference to SFS design.