Design Model for COD Removal in Constructed Wetlands Based on Biofilm Activity

This paper documents the performance of a subsurface-flow constructed wetlands system during its initial five years of operation under variable loading and operating conditions associated with a northern midwestern US climate. The results indicate that effective and sufficient CW seasonal removals of TSS, VSS, CBOD5, COD, and fecal coliform were achieved. Wastewater temperatures seemed to affect CBOD5 and COD removal rates. Nitrogen and phosphorus reductions were not as effective and varied seasonally, as well as with wastewater temperature. The addition of a sand filter, to aid in further nitrification and disinfection following CW treatment, markedly improved the performance of the wetlands system. After a few years of operation, the remarkable performance of the CW system was dampened by apparent clogging and subsequent eruption of wastewater at the head-end of the treatment cells. While clogging was partially caused by biomass build-up in the wetlands substrate, visual observations suggest that excessive vegetation coupled with relaxed maintenance may also be responsible for clogging.

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Methane oxidation in vertical flow constructed wetlands and its effect on denitrification and COD removal

Ecological Engineering ◽

10.1016/j.ecoleng.2018.12.029 ◽

2019 ◽

Vol 128 ◽

pp. 77-88 ◽

Cited By ~ 1

Author(s):

Thomas Schalk ◽

Johannes Effenberger ◽

Alexander Jehmlich ◽

Jens Nowak ◽

Heribert Rustige ◽

...

Keyword(s):

Methane Oxidation ◽

Constructed Wetlands ◽

Cod Removal ◽

Vertical Flow ◽

Vertical Flow Constructed Wetlands

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An artificial neural network model and design equations for BOD and COD removal prediction in horizontal subsurface flow constructed wetlands

Chemical Engineering Journal ◽

10.1016/j.cej.2007.12.029 ◽

2008 ◽

Vol 143 (1-3) ◽

pp. 96-110 ◽

Cited By ~ 73

Author(s):

Christos S. Akratos ◽

John N.E. Papaspyros ◽

Vassilios A. Tsihrintzis

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Constructed Wetlands ◽

Network Model ◽

Neural Network Model ◽

Artificial Neural Network Model ◽

Subsurface Flow ◽

Cod Removal ◽

Artificial Neural ◽

Horizontal Subsurface Flow

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Nitrogen and COD Removal from Domestic and Synthetic Wastewater in Subsurface-Flow Constructed Wetlands

Water Environment Research ◽

10.2175/106143013x13736496909022 ◽

2013 ◽

Vol 85 (9) ◽

pp. 855-862 ◽

Cited By ~ 5

Author(s):

R. S. Collison ◽

M. E. Grismer

Keyword(s):

Constructed Wetlands ◽

Subsurface Flow ◽

Cod Removal ◽

Synthetic Wastewater ◽

Subsurface Flow Constructed Wetlands

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Enhancement of COD removal in constructed wetlands treating saline wastewater: Intertidal wetland sediment as a novel inoculation

Journal of Environmental Management ◽

10.1016/j.jenvman.2019.109398 ◽

2019 ◽

Vol 249 ◽

pp. 109398 ◽

Cited By ~ 7

Author(s):

Qian Wang ◽

Zhenfeng Cao ◽

Qian Liu ◽

Jinyong Zhang ◽

Yanbiao Hu ◽

...

Keyword(s):

Constructed Wetlands ◽

Cod Removal ◽

Wetland Sediment ◽

Saline Wastewater ◽

Intertidal Wetland

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Winery and distillery wastewater treatment by constructed wetland with shorter retention time

Water Science & Technology ◽

10.2166/wst.2010.206 ◽

2010 ◽

Vol 61 (10) ◽

pp. 2611-2615 ◽

Cited By ~ 19

Author(s):

A. R. Mulidzi

Keyword(s):

Constructed Wetlands ◽

Constructed Wetland ◽

Retention Time ◽

Gradual Increase ◽

Oxygen Demand ◽

Cod Removal ◽

Secondary Treatment ◽

Sodium Magnesium ◽

Distillery Wastewater ◽

The Impact

The rationale for using constructed wetlands for treating wastewater is that wetlands are naturally among the most biological active ecosystem on earth. The aim of the study was to determine the impact of shorter retention time on the performance of constructed wetland in terms of Chemical Oxygen Demand (COD) and other elements removal. The application of wastewater with retention time of seven days as well as the evaluation of water quality after treatment at Goudini experimental wetland was carried out throughout the year. The results had shown an overall average COD removal of 60% throughout the year. Results also showed reasonable removal of other elements namely; potassium, pH, nitrogen, electrical conductivity, calcium, sodium, magnesium and boron from the wastewater by constructed wetlands. The results showed low COD removal during July until September after which it improved tremendously. The reason for low COD removal during first three months could be attributed to the fact that there was no gradual increase of wastewater application to the wetlands i.e. from 4,050 litres per day to 8,100 litres per day. The results had showed that constructed wetland as a secondary treatment system is effective in terms of COD and other elements removal from winery and distillery wastewater. COD removal throughout the year was 60% with seven days retention time. When compared with previous studies that showed 80% COD removal within 14 days retention time, therefore the 60% removal is very critical to wine industries as more wastewater will be applied to the system.

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