Long-term performance of constructed wetlands with horizontal sub-surface flow: Ten case studies from the Czech Republic

2011 ◽  
Vol 37 (1) ◽  
pp. 54-63 ◽  
Author(s):  
Jan Vymazal
Keyword(s):  
Czech Republic ◽  
Case Studies ◽  
Constructed Wetlands ◽  
Surface Flow ◽  
The Czech Republic ◽  
Long Term Performance ◽  
Term Performance

Using constructed wetlands to treat subsurface drainage from intensively grazed dairy pastures in New Zealand

2003 ◽  
Vol 48 (5) ◽  
pp. 207-213 ◽  
Author(s):  
C.C. Tanner ◽  
M. Long Nguyen ◽  
J.P.S. Sukias
Keyword(s):  
New Zealand ◽  
Constructed Wetlands ◽  
Subsurface Drainage ◽  
Organic N ◽  
Nutrient Concentrations ◽  
Start Up ◽  
Catchment Areas ◽  
Long Term Performance ◽  
Term Performance

Performance data, during the start-up period, are presented for constructed wetlands treating subsurface drainage from dairy pastures in Waikato (rain-fed) and Northland (irrigated), North Island, New Zealand. The wetlands comprised an estimated 1 and 2% of the drained catchment areas, respectively. Nitrate concentrations were high in the drainage inflows at both sites (medians 10 g m-3 at Waikato and 6.5 g m-3 at Northland), but organic N was also an important form of N at Waikato (37% of TN). Comparison of wetland inflow and outflow nutrient concentrations showed overall nutrient reductions during passage through the wetlands for NO3-N (34 and 94% for medians, respectively), TN (56 and 33%, respectively), and DRP (80%, Northland only). Median NH4-N (both sites) and DRP (Waikato) concentrations showed apparent increases between the wetland inlets and outlets. However, a mass balance calculated for the 3 month preliminary monitoring periods showed substantial mass removal of DRP (80%) and all measured forms of N (NO3-N 78%, NH4-N 41%, Org-N 99.8% and TN 96%) in the Waikato wetland. Monitoring of these systems needs to be continued through a range of seasons and years to fully assess their long-term performance.

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