Controlling factors for water residence time and flow patterns in Ekeby treatment wetland, Sweden

Kjellin, Johan; Wörman, Anders; Johansson, Håkan; Lindahl, Anna

doi:10.1016/j.advwatres.2006.07.002

Cited by 64 publications

(45 citation statements)

References 12 publications

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“…The spatial distribution of the flow velocity was non-uniform and consistent with the results of previous tracer experiments [39]. The flow velocity ranged from 0.00005 m·s −1 to 0.0001 m·s −1 in the shallow-water area and from 0.00001 m·s −1 to 0.00008 m·s −1 in the deep-water area.…”

Section: Flow Hydrodynamics and Hydraulic Performancesupporting

confidence: 87%

Tracer Experiments and Hydraulic Performance Improvements in a Treatment Pond

Shih

Zeng

Lee

et al. 2017

Water

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Abstract:The treatment efficiency of a wetland constructed for nutrient removal depends strongly on the flow patterns and residence times of the wetland. In this study, a tracer experiment was performed to estimate the residence time distribution and the hydraulic efficiency of a treatment pond with shallow and deep-water areas. Rhodamine WT experiments revealed a non-uniform flow pattern in the deep-water area and an overall poor hydraulic efficiency in the wetland. To improve flow uniformity and hydraulic efficiency, several design options for different inlet-outlet configurations, flow rates, water depths, and emergent baffle additions were considered. The effects on hydraulic performance were investigated through mathematical model simulations. The results revealed that increasing the flow rate and decreasing the water depth slightly improved the hydraulic performance, whereas changing the positions of the inlet and outlet produced inconsistent effects. The most effective improvement involved installing emergent baffles, with the number of baffles presenting the largest positive effect, followed by the width and length of the baffles. Long and thin baffles resulted in a uniform flow velocity field, a meandering flow path, and greater residence times and effective volume ratios. The installation of two baffles increased the hydraulic efficiency to 1.00, indicating excellent hydraulic performance. The thin baffles occupied approximately 3.7%-6.3% of the deep-water area and 1.9%-3.2% of the entire pond, indicating the potential for their practical application in limited land use regions.

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Section: Flow Hydrodynamics and Hydraulic Performancesupporting

confidence: 87%

Tracer Experiments and Hydraulic Performance Improvements in a Treatment Pond

Shih

Zeng

Lee

et al. 2017

Water

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“…Several features, such as wetland shape (Persson, 2000;Wörman and Kronnäs, 2005), inlet and outlet location (Persson et al, 1999;Suliman et al, 2006), wetland bottom topography (Kjellin et al, 2007;Lightbody et al, 2007) and vegetation distribution (Persson et al, 1999;Dal Cin and Persson, 2000;Serra et al, 2004;Kjellin et al, 2007;Keefe et al, 2010), can affect hydraulic characteristics of FWS wetlands. Persson et al (1999) and Persson (2000) showed that an island located near the wetland inlet enhanced the distribution of incoming water and thus the hydraulics.…”

Section: Introductionmentioning

confidence: 99%

Tracer behaviour and analysis of hydraulics in experimental free water surface wetlands

Bodin

Mietto

Ehde

et al. 2012

Ecological Engineering

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“…Preferential flow paths in the subsurface, for instance, can lead to considerable variability in the HRT. The heterogeneity of the filtering media is due to multiple factors, including (i) changes in porosity and (ii) grain size distribution, (iii) presence of plant roots and rhizomes, (iv) biological, physical and chemical clogging and (v) variations induced by different packing and compaction of the bed (Persson et al, 1999;Rash and Liehr, 1999; 5 García et al, 2004;Małoszewski et al, 2006;Kjellin et al, 2007;Brovelli et al, 2009;Leverenz et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Design methodology accounting for the effects of porous medium heterogeneity on hydraulic residence time and biodegradation in horizontal subsurface flow constructed wetlands

Brovelli

Carranza-Díaz

Rossi

et al. 2011

Ecological Engineering

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Horizontal flow constructed wetlands are engineered systems capable of eliminating a wide range of pollutants from the aquatic environment. Nevertheless, poor hydrodynamic behavior is commonly found resulting in preferential pathways and variations in both (i) the hydraulic residence time distribution (HRTD) and, consequently, (ii) the wetland's treatment efficiency. The aim of this work was to outline a methodology for wetland design that accounts for the effect of heterogeneous hydraulic properties of the porous substrate on the HRTD and treatment efficiency. Biodegradation of benzene was used to illustrate the influence of hydraulic conductivity heterogeneity on wetland efficiency. Random, spatially correlated hydraulic conductivity fields following a log-normal distribution were generated

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Controlling factors for water residence time and flow patterns in Ekeby treatment wetland, Sweden

Cited by 64 publications

References 12 publications

Tracer Experiments and Hydraulic Performance Improvements in a Treatment Pond

Tracer Experiments and Hydraulic Performance Improvements in a Treatment Pond

Tracer behaviour and analysis of hydraulics in experimental free water surface wetlands

Design methodology accounting for the effects of porous medium heterogeneity on hydraulic residence time and biodegradation in horizontal subsurface flow constructed wetlands

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