Rerating capacity of a constructed wetland treatment system

The 482-hectare (ha) City of Orlando (Florida) Easterly Wetlands (OEW) was designed to reduce nutrient concentrations in 0.90 m3/s of wastewater from the Iron Bridge Regional Water Reclamation Facility. Design influent nutrient concentrations were 6 mg/L total nitrogen (TN) and 0.75 mg/L total phosphorus (TP). Actual TN and TP concentrations have been less than design, averaging 2.6 mg/L and 0.29 mg/L, respectively from January 1988 through December 1999. If influent concentrations remain at these levels, the OEW may have the potential to treat significantly higher flows since less than 20% of the total area was utilized for nutrient reduction. To test this theory, a capacity study was performed for approximately nine months in 1997 and 1998. Simulated flows of approximately 1.26 m3/s, 1.66 m3/s, and 1.93 m3/s were tested. It was found that approximately 15% of the area was utilized for nutrient reduction during the 1.26 m3/s simulation, 35% in the 1.66 m3/s, and 1.93 m3/s simulations. Based on these testing results, an application was submitted to the state in early 2000 to increase the permitted capacity to 1.57 m3/s.

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CONTAMINATION OF THE ROOT VEGETABLES WASH WATER AND ITS TREATMENT EFFICIENCY

Proccedings of International Scientific Conference "RURAL DEVELOPMENT 2017" ◽

10.15544/rd.2017.010 ◽

2018 ◽

Author(s):

Midona DAPKIENĖ ◽

Nomeda SABIENĖ ◽

Algirdas RADZEVIČIUS

Keyword(s):

Wastewater Treatment ◽

Total Nitrogen ◽

Total Phosphorus ◽

Constructed Wetland ◽

Suspended Solids ◽

Oxygen Demand ◽

Wash Water ◽

Treatment System ◽

Wastewater Treatment System ◽

Root Vegetables

Growing volume of washed vegetables in Europe and Lithuania means that more drinking water is consumed and more wastewater is produced. Farmers, who engage in washing vegetables, face the problems of wastewater treatment, wastewater storage and utilization. Wastewater released to the environment from their farms would meet hygiene and environmental protection criteria. The aim of the study was to assess the contamination of the root vegetable wash water and to evaluate the possiblity of cleaning of wastewater in the land-based treatment system consisting of one constructed wetland and two biological ponds. The contamination of wastewater, produced by washed root vegetables, in Lithuanian farms was measured according to suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen and total phosphorus. Pollution of the wash water and wastewater was evaluated comparing the mean values with legislative limit values and with typical sewage contamination values. In all farms wastewater of initial root vegetables washing was treated in settling basins. Wastewater of one carrots washing farm was treated in the land-based wastewater treatment system consisting of surface flow constructed wetland and two biological ponds. Efficiency of the wastewater treatment in this system was according to suspended solids 90%, BOD7 – 97%, CODCr – 92%, total nitrogen – 98% , total phosphorus – 97%. The result shows, that the natural wastewater treatment system is suitable for farms, that wash and produce vegetables, but before releasing wastewater to the environment, it has to be settled.

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Effect of hydraulic retention time on chemical oxygen demand and total nitrogen removal in intermittently aerated constructed wetlands

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2504 ◽

2020 ◽

Vol 15 (3) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Isabela Pires da Silva ◽

Gabriela Barbosa da Costa ◽

João Gabriel Thomaz Queluz ◽

Marcelo Loureiro Garcia

Keyword(s):

Chemical Oxygen Demand ◽

Constructed Wetlands ◽

Total Nitrogen ◽

Total Phosphorus ◽

Constructed Wetland ◽

Retention Time ◽

Hydraulic Retention Time ◽

Subsurface Flow ◽

Oxygen Demand ◽

Intermittent Aeration

This study evaluated the effect of hydraulic retention time on chemical oxygen demand (COD) and total nitrogen (TN) removal in an intermittently aerated constructed wetlands. Two horizontal subsurface-flow constructed wetlands were used: one without aeration and the other aerated intermittently (1 hour with aeration/7 hours without aeration). Both systems were evaluated treating domestic wastewater produced synthetically. The flow rate into the two CWs was 8.6 L day-1 having a hydraulic retention time of 3 days. The results show that the intermittently aerated constructed wetland were highly efficient in removing COD (98.25%), TN (83.60%) and total phosphorus (78.10%), while the non-aerated constructed wetland showed lower efficiencies in the removal of COD (93.89%), TN (48.60%) and total phosphorus (58.66). These results indicate, therefore, that intermittent aeration allows the simultaneous occurrence of nitrification and denitrification processes, improving the removal of TN in horizontal subsurface-flow constructed wetlands. In addition, the use of intermittent aeration also improves the performance of constructed wetlands in removing COD and total phosphorus.

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The Efficiency and Reliability of Pollutant Removal in a Hybrid Constructed Wetland with Common Reed, Manna Grass, and Virginia Mallow

Water ◽

10.3390/w10101445 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1445 ◽

Cited By ~ 8

Author(s):

Michał Marzec ◽

Krzysztof Jóźwiakowski ◽

Anna Dębska ◽

Magdalena Gizińska-Górna ◽

Aneta Pytka-Woszczyło ◽

...

Keyword(s):

Total Nitrogen ◽

Total Phosphorus ◽

Constructed Wetland ◽

Suspended Solids ◽

Treatment Plant ◽

Oxygen Demand ◽

Total Suspended Solids ◽

Common Reed ◽

Pollutant Removal ◽

Limit Values

In this paper, the pollutant removal efficiency and the reliability of a vertical and horizontal flow hybrid constructed wetland (CW) planted with common reed, manna grass, and Virginia mallow were analyzed. The wastewater treatment plant, located in south-eastern Poland, treated domestic sewage at an average flow rate of 2.5 m3/d. The tests were carried out during five years of its operation (2014–2018). The following parameters were measured: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids, total nitrogen, and total phosphorus. The results showed that more than 95% of BOD5, COD, and total phosphorus was removed in the tested CW system. The average effectiveness of removal of total suspended solids and total nitrogen exceeded 86%. A reliability analysis performed using the Weibull probability model showed that the removal reliability in the tested CW was very high for BOD5, COD, total suspended solids, and total phosphorus (100%). The probability that the total nitrogen concentration in the treated effluents would reach the limit value (30 mg/L) established for effluents discharged from a treatment plant of less than 2000 PE (population equivalent) to standing waters was 94%. The values of all the pollution indicators in wastewater discharged to the receiver were significantly lower than the limit values required in Poland. The investigated hybrid CW system with common reed, manna grass, and Virginia mallow guaranteed stable low values of BOD5, COD, total suspended solids, and total phosphorus in the treated wastewater, which meant it was highly likely to be positively evaluated in case of an inspection.

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Modelling constructed wetland treatment system performance

Ecological Modelling ◽

10.1016/j.ecolmodel.2007.02.030 ◽

2007 ◽

Vol 205 (3-4) ◽

pp. 355-364 ◽

Cited By ~ 46

Author(s):

Volodymyr Tomenko ◽

Sirajuddin Ahmed ◽

Viktor Popov

Keyword(s):

Constructed Wetland ◽

System Performance ◽

Treatment System ◽

Wetland Treatment

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Modeling nitrogen removal in a constructed wetland treatment system

Water Science & Technology ◽

10.2166/wst.2009.319 ◽

2009 ◽

Vol 60 (2) ◽

pp. 301-309 ◽

Cited By ~ 4

Author(s):

P. G. Sonavane ◽

G. R. Munavalli

Keyword(s):

Nitrogen Removal ◽

Constructed Wetland ◽

Kinetic Models ◽

Plant Uptake ◽

Field Experiments ◽

Treatment System ◽

Effective Control ◽

Distributed Parameter ◽

Distributed Parameter Model ◽

Wetland Treatment

A constructed wetland treatment system (CWTS) has been adopted for removal of nitrogen from wastewater. The design methodologies developed for CWTS in previous studies were based on thumb rules, and first order/Monod type kinetics models. The use of kinetic models is system/environment specific. There is scope to assess the potential of other reaction kinetic models for their usefulness and applicability. In the present study, lumped and distributed parameter models incorporated with various reactions kinetic were developed. The various processes were incorporated in distributed parameter model for nitrogen transformations. Laboratory/pilot-scale field experiments were carried out and used for verification and application of models developed. The reaction rate parameters were estimated using non-linear least square analysis. The results showed that the conditions within CWTS can be simulated by plug flow. The plant uptake rate was found to be higher than denitrification for nitrate removal. Nitrification and plant uptake are equally dominant for the removal of ammonia nitrogen. The relative contributions by various processes for nitrogen removal can be established using the distributed parameter model. The developed simulation model can be used as a CWTS planning and design tool for the effective control and treatment of nitrogen induced pollution.

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