Potential of constructed wetland in reducing total nitrogen loading into the Truckee River

Abstract

A pilot-scale wetland was constructed along Steamboat Creek (SBC) at the Truckee Meadows Water Reclamation Facility (TMWRF), Sparks, Nevada. SBC is a major non-point source of total nitrogen (TN) for the Truckee River. In this study, four (16.2 m 2 ) parallel wetland trains with two different experimental designs were utilized to assess seasonal variations in TN. The experimental designs included: (1) SBC water and SBC sediments (Configuration-1) and (2) TMWRF effluent and SBC sediments (Configuration-2). Over a period of 2 years, the TN in both designs was routinely monitored. TN was reduced by an average of 47% (0.60 mg/l) in Configuration-1 and an average of 24% (0.39 mg/l) in Configuration-2. Nitrogen speciation was an important factor influencing the effectiveness of nitrogen removal within the wetland system. Ammonia-N (NH 3 -N) and nitrate plus nitrite nitrogen ((NO 3 + NO 2 )-N) were removed more effectively than organic nitrogen. The results obtained from this pilot-scale wetland system suggest that a proposed large-scale constructed wetlands system along SBC would be expected to overall reduce TN loading into the Truckee River from 19 to 30% on an annual basis.

Nitrogen retention in natural Mediterranean wetland-streams affected by agricultural runoff

“…In fact, studies performed in these regions show that NO − 3 -N retention efficiency is controlled mainly by the temperature (Spieles and Mitsch, 2000;Chavan et al, 2008). In the studied wetland-streams, NO − 3 -N retention efficiency tended to increase in summer months although significant differences among seasons were only observed in the Taray wetland (the lack of statistical significance for Parra wetland may be explained by the absence of data from July to September 2007, during the drought period).…”

“…However, few studies have analyzed nutrient retention efficiencies in natural wetlands (Jordan et al, 2003;Vellidis et al, 2003;Fisher and Acreman, 2004;Knox et al, 2008), despite some studies demonstrating their utility in water quality control on the catchment scale (Mitsch, 1992;Mitsch et al, 2005;Chavan et al, 2008). Indeed, the European Framework Directive (2000/60/EC) emphasizes the role of wetlands as significant elements of the hydrological networks required to obtain a "good water status" for surface and ground waters (Wetlands Horizontal Guidance, 2003).…”

Nitrogen retention in natural Mediterranean wetlands affected by agricultural runoff

“…The retention capacity of wetlands varies seasonally, particularly in temperate regions where biological activity diminishes in winter (Howard-Williams, 1985;. In fact, studies performed in these regions show that NO − 3 -N retention efficiency is controlled mainly by the temperature (Spieles and Mitsch, 2000;Chavan et al, 2008). In the studied wetland-streams, NO − 3 -N retention efficiency tended to increase in summer months although significant differences among seasons were only observed in the Taray wetland (the lack of statistical significance for Parra wetland may be explained by the absence of data from July to September 2007, during the drought period).…”

“…2360 V. García-García et al: N retention in natural Mediterranean wetland-streams Nitrogen retention efficiency in constructed wetlands has been extensively studied for wetlands to be used in conjunction with agricultural drainage and wastewater treatment systems (Spieles and Mitsch, 2000). However, few studies have analyzed nutrient retention efficiencies in natural wetlands (Jordan et al, 2003;Vellidis et al, 2003;Fisher and Acreman, 2004;Knox et al, 2008), despite some studies demonstrating their utility in water quality control on the catchment scale (Mitsch, 1992;Mitsch et al, 2005;Chavan et al, 2008). Indeed, the European Framework Directive (2000/60/EC) emphasizes the role of wetlands as significant elements of the hydrological networks required to obtain a "good water status" for surface and ground waters (Wetlands Horizontal Guidance, 2003).…”

Transport and Fate of Nitrate in the Streambed of a Low-Gradient Stream

“…Nitrate concentrations are typically lowest during summer, when there is a limited source of NO 3 -N and there is increased uptake from growing plants [38,45]. The rate of denitrification, which is lowest during the winter months (November to March) and highest in early spring and summer (April to July), influences the seasonal variation of NO 3 -N concentrations in streams [4,47]. Moreover, the decrease in winter denitrification rates is attributed to a decrease in temperature and in microbial activity.…”