Cost Comparison Of Surface Flow Constructed Wetlands And Subsurface Flow Constructed Wetlands Based On Pollutants Removal Rate And Land Price

Constructed wetlands are divided into two types,Surface Flow Constructed Wetland(SFW)and Subsurface Flow Constructed Wetland(SSFW).Compared to SSFW,SFW requires higher land costs and lower infrastructure and operating costs for the same pollutants removal efficiency.This study estimated and compared the life-cycle costs of two constructed wetlands in the condition of specific land price and pollutants removal demand based on first-order dynamic model and the constructed wetland equation released by EPA.Main conclusions of the study are as follows:the economic cost of pollutants(NH3-N?TN?TP)removal grows exponentially as the land price and removal rate rise.SFW costs less than SSFW in removing NH3-N from water however the temperature and land price change.The temperature increment has no effect on the cost of removing TP,while costs of removing NH3-N and TP decrease.SFW economic cost is less than SSFW when land price and pollutant removal efficiency are low,but costs more than SSFW after land price and pollutant removal efficiency increased.This paper provides economic optimal advice on constructed wetlands,and will accelerate the process of widespread use and economic evaluation of constructed wetland treating low-polluted water.