Iron scraps enhance simultaneous nitrogen and phosphorus removal in subsurface flow constructed wetlands

In this study, plant growth and nitrogen and phosphorus removal efficiency in lab-scale CWs by five plants (H. vulgaris, N. peltatum, N. tetragona, N. pumilum, S. trifolia) in winter in Sichuan basin was evaluated. H. vulgaris and N. tetragona would well adapt to the winter wetland environment, and the relative growth at the end of the experiment was 89.83% and 66.85%, respectively. In winter, H. vulgaris kept growing with accumulated stems and leaves, while growth of N. tetragona was mainly caused by the growth of roots and stems underwater. In addition, during the winter, removal efficiencies were 66.29%, 57.47%, 54.78%, 55.47%, 41.66% of TN and 62.40%, 69.75%, 69.97%, 65.65%, 76.55% of TP for each planted CWs respectively. The results indicated that the removal of nitrogen and phosphorus from CWs was mainly achieved by substrate, while a small portion was attributed by plant. However, plants like H. vulgaris and N. tetragona, in the CWs in winter can play the role of landscaping. Thus, H. vulgaris could be considered as a suitable and effective nutrient removal plant for treatment of nitrogen and phosphorus water in winter wetlands in Sichuan basin.

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Subsurface-flow constructed wetlands treatment in the plains: five years of experience

Water Science & Technology ◽

10.2166/wst.2001.0854 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 375-380 ◽

Cited By ~ 21

Author(s):

M.F. Dahab ◽

R.Y. Surampalli

Keyword(s):

Constructed Wetlands ◽

Fecal Coliform ◽

Subsurface Flow ◽

Operating Conditions ◽

Cod Removal ◽

Variable Loading ◽

Nitrogen And Phosphorus ◽

Removal Rates ◽

Sand Filter ◽

Subsurface Flow Constructed Wetlands

This paper documents the performance of a subsurface-flow constructed wetlands system during its initial five years of operation under variable loading and operating conditions associated with a northern midwestern US climate. The results indicate that effective and sufficient CW seasonal removals of TSS, VSS, CBOD5, COD, and fecal coliform were achieved. Wastewater temperatures seemed to affect CBOD5 and COD removal rates. Nitrogen and phosphorus reductions were not as effective and varied seasonally, as well as with wastewater temperature. The addition of a sand filter, to aid in further nitrification and disinfection following CW treatment, markedly improved the performance of the wetlands system. After a few years of operation, the remarkable performance of the CW system was dampened by apparent clogging and subsequent eruption of wastewater at the head-end of the treatment cells. While clogging was partially caused by biomass build-up in the wetlands substrate, visual observations suggest that excessive vegetation coupled with relaxed maintenance may also be responsible for clogging.

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Comparison of measured and simulated distribution of microbial biomass in subsurface vertical flow constructed wetlands

Water Science & Technology ◽

10.2166/wst.2007.496 ◽

2007 ◽

Vol 56 (3) ◽

pp. 233-240 ◽

Cited By ~ 10

Author(s):

G. Langergraber ◽

A. Tietz ◽

R. Haberl

Keyword(s):

Microbial Biomass ◽

Constructed Wetlands ◽

Reactive Transport ◽

Municipal Wastewater ◽

Subsurface Flow ◽

Measured Data ◽

Model Parameters ◽

Nitrogen And Phosphorus ◽

Simulation Results ◽

Subsurface Flow Constructed Wetlands

The multi-component reactive transport module CW2D has been developed to model transport and reactions of the main constituents of municipal wastewater in subsurface flow constructed wetlands and is able to describe the biochemical elimination and transformation processes for organic matter, nitrogen and phosphorus. It has been shown that simulation results match the measured data when the flow model can be calibrated well. However, there is a need to develop experimental techniques for the measurement of CW2D model parameters to increase the quality of the simulation results. Over the last years methods to characterise the microbial biocoenosis in vertical subsurface flow constructed wetlands have been developed. The paper shows measured data for microbial biomass and their comparison with simulation results using different heterotrophic lysis rate constants.

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Simulation of subsurface flow constructed wetlands - results and further research needs

Water Science & Technology ◽

10.2166/wst.2003.0308 ◽

2003 ◽

Vol 48 (5) ◽

pp. 157-166 ◽

Cited By ~ 38

Author(s):

G. Langergraber

Keyword(s):

Constructed Wetlands ◽

Reactive Transport ◽

Transport Model ◽

Subsurface Flow ◽

Pilot Scale ◽

Research Needs ◽

Nitrogen And Phosphorus ◽

Surface Water Treatment ◽

Hydraulic Behaviour ◽

Subsurface Flow Constructed Wetlands

Simulation of constructed wetlands has two main tasks: to obtain a better understanding of the processes in constructed wetlands, and to check and optimise existing design criteria. This paper shows simulation results for two indoor pilot-scale constructed wetlands for wastewater and surface water treatment respectively. The results presented and discussed are mainly focussed on the hydraulic behaviour of the constructed wetland systems. In addition results of reactive transport simulations with CW2D are shown. The multi-component reactive transport model CW2D (Constructed Wetlands 2 Dimensional) was developed to model transport and reactions of the main constituents of wastewater (organic matter, nitrogen, and phosphorus) in subsurface flow constructed wetlands. For the pilot-scale constructed wetlands a calibration of the flow model was possible and therefore the results of the reactive transport simulations with CW2D fit the measured data well. The further research needs regarding the simulation of subsurface flow constructed wetlands are discussed.

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