Abstract
Two floating treatment wetlands (FTWs) in experimental tanks were compared in terms of their effectiveness on removing nutrients. The results showed that the FTWs were dominated by emergent wetland plants and were constructed to remove nutrients from simulated urban stormwater. Iris pseudacorus and Thalia dealbata wetland systems were effective in reducing the nutrient. T. dealbata FTWs showed higher nutrient removal performance than I. pseudacorus FTWs. Nitrogen (N) and phosphorous (P) removal rates in water by T. dealbata FTWs were 3.95 ± 0.19 and 0.15 ± 0.01 g/m2/day, respectively. For I. pseudacorus FTWs, the TN and TP removal rates were 3.07 ± 0.15 and 0.14 ± 0.01 g/m2/day, respectively. The maximum absolute growth rate for T. dealbata corresponded directly with the maximum mean nutrient removal efficiency during the 5th stage. At harvest, N and P uptak of T. dealbata was 23.354 ± 1.366 g and 1.489 ± 0.077 g per plant, respectively, approximate twice as high as by I. pseudacorus.
Highlights
To control the quality of urban stormwater and reduce pollutant mass loading prior to discharge into receiving water bodies, floating treatment wetlands (FTWs) as one emerging best management practices (BMPs) which restore receiving water using a variety of biological and physical processes, provide nutrients removal through simultaneously hydrological and biological controls relating to various hydrobiogeochemical processes in a multimedia pond environment[1, 5]
dissolved oxygen (DO), total nitrogen (TN) and total phosphorus (TP) levels in the effluent were significantly lower in T. dealbata FTWs than in I. pseudacorus FTWs (p < 0.05)
Differences in average nutrient removal efficiencies (REs) between T. dealbata and I. pseudacorus FTWs were significant over the study period (p < 0.05) (Table 1)
Summary
To control the quality of urban stormwater and reduce pollutant mass loading prior to discharge into receiving water bodies, floating treatment wetlands (FTWs) as one emerging best management practices (BMPs) which restore receiving water using a variety of biological and physical processes, provide nutrients removal through simultaneously hydrological and biological controls relating to various hydrobiogeochemical processes in a multimedia pond environment[1, 5]. In FTWs, plants are grown on floating mats and the root systems of the species are suspended in the water column rather than rooted in sediments, so FTWs offer great promise for rainfall-driven stormwater treatment applications as they are conducive to settling by reducing turbulence and wave mixing induced by wind and thermal factors[6,7,8]. These are the main key differences between FTWs and traditional wetland systems where the majority of pollutants are removed through the gravel matrix or sediment rather than the water column[9]. The influences of seasonal variation on FTWs, plant harvesting strategy, and the role of microorganisms in nutrient removal have not been well studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
