Denitrification in constructed free-water surface wetlands: II. Effects of vegetation and temperature

Bachand, Philip A.M.; Horne, Alexander J.

doi:10.1016/s0925-8574(99)00017-8

Cited by 264 publications

(164 citation statements)

References 34 publications

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“…Biological denitrification is highly depended on temperature [1,25,31,36,43], and it was reported to slow down below 15˚C and nearly cease below 5˚C due to the drastically dropped activities of denitrifying bacteria [11]. In our experiment, the sharp decrease of NO À 3 -N removal rate observed in January ( Fig.…”

Section: Low Temperaturesupporting

confidence: 46%

“…Conventional wastewater treatment plants with activated sludge are usually effective in removing Chemical oxygen demand (COD) and ammonia in wastewaters, but the effluent, so-called tail water, is usually characterized by high nitrate concentrations [1][2][3][4]. In addition, nitrate is the predominant form of nitrogen pollutants in nonpoint drainage from fertile agricultural fields [5,6] and groundwater [7,8].…”

Section: Introductionmentioning

confidence: 99%

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Nitrate removal from tail water by integrated vertical-flow constructed wetlands at a high hydraulic loading rate

Chang¹,

Wu²,

Dai³

et al. 2013

Desalination and Water Treatment

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A B S T R A C TNitrate removal rates of two pilot-scale integrated vertical-flow constructed wetlands (IVCWs) treating tail water, under a hydraulic loading rate (HLR) of 250 mm/d with a mean influent NO À 3 -N concentration of 24.4 mg·L À1 , were evaluated. Mean NO À 3 -N removal efficiencies of 15.5 and 18.5% with mass removal rates of 1.01 g·m À2 ·d À1 and 1.16 g·m À2 ·d À1 for IVCW 1 (planted with Canna indica and Pontederia cordata) and 2 (planted with Typha orientalis and Arundo donax var. versicolor), respectively, were achieved. The removal rate constants as fitted by the first-order area-based model averaged 0.046 and 0.055 m·d À1 , respectively. Since NO À 3 -N was the dominant nitrogen form in the effluent, denitrification was the limiting step in nitrogen removal despite of favorable pH and anaerobic conditions in the wetland beds. Low availability of carbon source, high HLR, and low temperature could be the probable influencing factors for the observed low NO À 3 -N removal efficiencies. However, IVCW could be used to treat tail water for nitrate removal at a comparable high loading rate.

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Section: Low Temperaturesupporting

confidence: 46%

Section: Introductionmentioning

confidence: 99%

Nitrate removal from tail water by integrated vertical-flow constructed wetlands at a high hydraulic loading rate

Chang¹,

Wu²,

Dai³

et al. 2013

Desalination and Water Treatment

View full text Add to dashboard Cite

show abstract

“…Interestingly, when analyzed at time scales on the order of days, the carbon supply in these systems appears as near steady-state and may produce apparent zero and first-order denitrification kinetics. These experiments suggest that the typically large annual variations and site-to-site variations in apparent zero-order denitrification rate constants at the field scale [10] may in part reflect plant carbon colimitation with NO 3 À . In full-scale wetlands that receive treated wastewater, high in dissolved NO 3 À and low in DOC, the supply of plant carbon may limit denitrification rates [25].…”

Section: Total Carbon Limitation In Constructed Wetlandsmentioning

confidence: 83%

“…In addition to such controlling factors as dissolved oxygen, temperature and pH, high rates of denitrification depend upon a readily available source of electron rich carbon [7,30]. Although aquatic plants provide the largest supply of readily oxidized carbon in wetlands, the wide site-to-site variation in apparent denitrification rates (i.e., 200 to over 5000 mg N m À2 d À1 ) in constructed wetlands [3,10] cannot be explained easily by plant species or the factors above.…”

Section: Introductionmentioning

confidence: 99%

Plant carbohydrate limitation on nitrate reduction in wetland microcosms

2002

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“…Possible reasons include (inter alia) less biological activity in winter, vegetation dormancy, temperature-dependent bio-chemical treatment processes, higher pollutant concentration and/or road salt in snowmelt/winter runoff (Kadlec and Reddy 2001;Weis and Weis 2004). Cold temperatures especially can affect the temperature-dependent nitrogen removal mechanisms (Bachand and Horne 1999). The daily mean air temperatures during the sampled events were 11°C ± 3°C, 15°C ± 3°C, 11°C ± 3°C and 1°C ± 0.1°C in spring, summer, autumn, and winter, respectively.…”

Section: Seasonal Performance Of the Csw For Pollutant Removalmentioning

confidence: 99%

Effectiveness of a 19-Year Old Combined Pond-Wetland System in Removing Particulate and Dissolved Pollutants

et al. 2017

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This study monitored the stormwater runoff quantity and quality treatment performance of a 6.8 ha 19-year old combined pond-wetland system, located in south Sweden, over one year. The mean volume reductions for 53 storm events for the pond and wetland were 40% and 28%, respectively, while the mean flow reductions were 60% and 76%, respectively. Pollutant concentrations in the influent to the wetland were highly variable. The pond-wetland system could efficiently remove an average of 91%, 80%, 94%, 91%, 83% and 92% of TSS, TP, particulate Cd, Cu, Pb, and Zn, respectively, whereas the removal of particulate and dissolved Ni was highly variable with an average of 67% ± 62% and −5% ± 41%, respectively. The removal of TN, NH 4 -N and NO 3 + NO 2 -N was highly variable with an average of 45% ± 27%, 12% ± 96% and 45% ± 43%, respectively. These removal percentages are high in comparison to other studies and underline that relatively old systems can also provide efficient treatment. Although the pond accounted for a substantial reduction of pollutant concentration, the wetland significantly enhanced both the treatment performance and the peak flow reduction. This underlines that a combined pond/wetland system is a more beneficial solution than a pond only. The pollutant removal efficiency was significantly influenced by some factors including Antecedent Dry Days, seasonal variations, air temperature, retention times, rainfall depth and duration, and peak rainfall intensity.

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Denitrification in constructed free-water surface wetlands: II. Effects of vegetation and temperature

Cited by 264 publications

References 34 publications

Nitrate removal from tail water by integrated vertical-flow constructed wetlands at a high hydraulic loading rate

Nitrate removal from tail water by integrated vertical-flow constructed wetlands at a high hydraulic loading rate

Plant carbohydrate limitation on nitrate reduction in wetland microcosms

Effectiveness of a 19-Year Old Combined Pond-Wetland System in Removing Particulate and Dissolved Pollutants

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