Cold-climate constructed wetlands

Mæhlum, Trond; Jenssen, Petter D.; Warner, William S.

doi:10.2166/wst.1995.0130

Cited by 63 publications

(37 citation statements)

References 3 publications

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“…With the exception of system 18, these wetlands treat fecal coliform with efficiencies commensurate with results reported for similar systems with different designs (Bhamidimarri et al, 1991;Maehlum et al, 1995;Neralla et al, 2000). Detailed analyses of the data and observer notes for system 18 may imply that cell 2 is responsible for the failure of this system.…”

Section: Fecal Coliformsupporting

confidence: 65%

“…Nitrogen (ammonia and total nitrogen) and phosphorus are also mitigated but with widely varying efficiencies compared with other pathogens (Nichols, 1983;Mann, 1990;UrbancBercic and Bulc, 1995;Koottatep and Polprasert, 1997;Cronk and Fennessy, 2001). Seasonal changes in load reduction efficiency appear to be minimal (Maehlum et al, 1995;Wittgren and Maehlum, 1997).…”

Section: Introductionmentioning

confidence: 97%

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Efficiency of small constructed wetlands for subsurface treatment of single-family domestic effluent

Steer

Fraser

Boddy

et al. 2002

Ecological Engineering

124

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Single-family constructed wetland systems in Ohio, USA, are studied to evaluate their effectiveness in improving water quality. Twenty-one, three-cell systems (septic tank with two wetlands) are found to meet US Environmental Protection Agency (EPA) effluent load guidelines in 68% of the quarterly water quality samples collected from 1994 to 2001. These wetlands most frequently meet EPA standards for mitigation of biochemical oxygen demand (89% below 30 mg/l); total suspended solids (79% below 30 mg/l); and fecal coliform (74% below 1000 counts/100 ml). Phosphorus and ammonia discharge meet the guidelines less often (50% at 1 mg/l and 16% at 1.5 mg/l, respectively). These data also indicate that domestic treatment wetlands can reduce output of fecal coliform 88 9 27%, total suspended solids 56 953%, biochemical oxygen demand 70 948%, ammonia 56 931% and phosphorus 80 920%. Analysis of variance for these systems indicates that biochemical oxygen demand reduction is 10% less efficiently reduced during winter and ammonia was reduced 20% more efficiently in fall when compared with the other seasons. Phosphorus reductions display complex seasonal variations that imply that the least efficient phosphorus reduction occurs in winter and the most efficient reduction occurs in fall.

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Section: Fecal Coliformsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 97%

Efficiency of small constructed wetlands for subsurface treatment of single-family domestic effluent

Steer

Fraser

Boddy

et al. 2002

Ecological Engineering

124

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“…A number of studies in United States have also shown significant removal efficiency by the wetland system (Steer et al, 2005;Huang et al, 2000). Wetlands have been found suitable for tropical climates (Kantawanichkul et al, 1999), and many European countries have found that wetlands can perform reasonably even in cold climates (Maehlum and Stalnacke, 1999;Maehlum et al, 1995;Haberl et al, 1995). Other examples can be found in Sundaravadivel and Vigneswaran (2001) (1) Constructed wetlands (CW) for INDOT rest stop wastewater treatment.…”

Section: Background and Motivationmentioning

confidence: 99%

“…On the other hand, systems with vertical flow show high percentage of removal of NH 3 -N (Kantawanichkul, 1999). Studies have shown that a combination of both types of flow is better than only vertical flow or only horizontal flow systems (White, 1995;Maehlum et al, 1995;Platzer, 1999). This is because vertical flow systems provide aerobic environments to enhance nitrification and horizontal flow systems provide anaerobic subsurface flow environments for denitrification, and nitrogen removal requires both the processes.…”

Section: Previous Workmentioning

confidence: 99%

The I-70 Greenfield Rest Area Wetland Projectss

Kao¹,

Chang²,

Sultana³

2009

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Prepared in cooperation with the Indiana Department of Transportation and Federal Highway Administration. AbstractOn-site treatment of wastewater at highway rest areas poses some unique and difficult challenges because of the rural locale, high variability in wastewater flow rate and strength, and lack of knowledgeable personnel on-site. As a potential alternative, a constructed subsurface wetland system was built at the I-70 rest stop nearby Greenfield, Indiana, in 2003. This wetland system, mainly composed of three wetland cells, also includes draw-and-fill and recirculation mechanisms to increase oxygen transfer to the wastewater and improve the overall treatment performance. Special considerations for highway rest areas have been emphasized. A dynamic hydraulic model was developed to help characterize the flows in the system and estimate the hydraulic retention time. The size of the Greenfield wetland was found to be sufficient in providing pretreatment that could help avoid potential surcharge from the local treatment plant, but was inadequate for direct onsite discharge. Though the draw-and-fill and recirculation mechanisms provided some treatment benefits, they raised the construction costs and maintenance needs. Constructed wetlands have been described as low-maintenance systems compared to other conventional wastewater treatment approaches, but proper maintenance of the wetland facilities was found to be a key factor in achieving good performance. Since wetland systems in highway rest areas have not been studied, this study provided useful information for possible future implementation of such systems. Key WordsWastewater treatment, wetlands, highway rest areas, recirculation system. Distribution StatementNo restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161 ACKNOWLEDGEMENTS Gratitude is expressed to the Joint Transportation Research Program (JTRP) at PurdueUniversity for providing the funds to conduct the research described here. Numerous people have been involved with this project in various capacities, and they have been listed below. Their help in this effort is acknowledged. SUMMARYOn-site treatment of wastewater at highway rest areas poses some unique and different challenges. As a potential alternative, a constructed subsurface wetland system was built at the I-70 rest stop nearby Greenfield, Indiana in 2003. This wetland system, mainly composing of three wetland cells, also includes special cyclic draw-and-fill and recirculation mechanisms to increase oxygen transfer to the wastewater and improve the overall treatment performance. Additionally, a sand mound biofield was also included to test the applicability of final treatment and subsurface discharge.After several years of system operation, this final report summarizes the overall project experience. The size of Greenfield wetland was found to be sufficient in providing pretreatment that could help avoid potential surcharge from the local treatment plant, bu...

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“…The LWA-or Filtralite-P-based hybrid CWs combined from VSSF and HSSF filters in series and treating domestic wastewater show equally high long-term efficiency in both summer and winter [3,[37][38][39][40]. Likewise, hybrid subsurface flow CWs used for landfill leachate treatment [41], as well as single or 2-stage VSSF and HSSF filters treating municipal effluents [42,43] show equally high performance in summer and winter.…”

Section: Introductionmentioning

confidence: 99%

The effects of flow regime and temperature on the wastewater purification efficiency of a pilot hybrid constructed wetland

Zaytsev¹,

Nurk²,

Põldvere³

et al. 2007

WIT Transactions on Ecology and the Environment, Vol 103

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A pilot scale experimental hybrid constructed wetland (CW) was established in 2005 for the treatment of mixed effluents from municipal sources and food processing plants in a small village in southern Estonia. The aim was to find optimal operating regimes (varying hydraulic loading rates, loading intervals, recirculation regimes and regimes of hydraulic retention time) for the use of analogous CWs in cold climates. The hybrid wetland system consists of two parallel systems designed on the same principle: a vertical subsurface flow (VSSF) filter followed by a horizontal subsurface flow (HSSF) filter. The VSSF filter of one system (the left filter) is filled with crushed limestone, while the other (right) is filled with light weight aggregates (LWA). Both HSSF filters are filled with LWA. From December 2005 until December 2006, water samples from the outlet of the septic tank and the outlet of both VSSF and HSSF filters were taken once a week. In both systems, a combination of decreasing hydraulic load (from 52 to 14 mm d-1) and increasing recirculation rate (from 34 to 300%) caused a significant increase in the purification efficiency of BOD7 (from 58 to 99%), N tot (from 11 to 82%), and NH4-N (from -16 to 83%). In both systems, the removal efficiency of P tot did not show any significant correlation with hydraulic load, whereas in the right (LWA) system, the increasing recirculation rate significantly increased P tot removal. The dynamics of the COD value was analogous to that of the BOD7 value, but no significant differences were found between the removal efficiency of total suspended solids (TSS) of different flow regimes. Likewise, water temperature did not show a significant correlation between the purification efficiency of all of the studied water quality indicators. For the successful functioning of hybrid CWs in a cold climate, optimal hydraulic load should be ≤20 mm d-1 with a recirculation rate of 150-300%.

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Cold-climate constructed wetlands

Cited by 63 publications

References 3 publications

Efficiency of small constructed wetlands for subsurface treatment of single-family domestic effluent

Efficiency of small constructed wetlands for subsurface treatment of single-family domestic effluent

The I-70 Greenfield Rest Area Wetland Projectss

The effects of flow regime and temperature on the wastewater purification efficiency of a pilot hybrid constructed wetland

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