Investigation of flow dynamics of wastewater in a pilot-scale constructed wetland using radiotracer technique

The aim of this study was to characterize the efficiency of an intensified process of vertical flow constructed wetland having the following particularities: (i) biological pretreatment by trickling filter, (ii) FeCl3 injection for dissolved phosphorus removal and (iii) succession of different levels of redox conditions along the process line. A pilot-scale set-up designed to simulate a real-scale plant was constructed and operated using real wastewater. The influences of FeCl3 injection and water saturation level within the vertical flow constructed wetland stage on treatment performances were studied. Three different water saturation levels were compared by monitoring: suspended solids (SS), total phosphorus (TP), dissolved chemical oxygen demand (COD), ammonium, nitrate, phosphate, iron, and manganese. The results confirmed the good overall efficiency of the process and the contribution of the trickling filter pretreatment to COD removal and nitrification. The effects of water saturation level and FeCl3 injection on phosphorus removal were evaluated by analysis of the correlations between the variables. Under unsaturated conditions, good nitrification and no denitrification were observed. Under partly saturated conditions, both nitrification and denitrification were obtained, along with a good retention of SSs. Finally, under saturated conditions, the performance was decreased for almost all parameters.

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Potential use of mangrove plantation as constructed wetland for municipal wastewater treatment

Water Science & Technology ◽

10.2166/wst.2003.0331 ◽

2003 ◽

Vol 48 (5) ◽

pp. 257-266 ◽

Cited By ~ 21

Author(s):

K. Boonsong ◽

S. Piyatiratitivorakul ◽

P. Patanaponpaiboon

Keyword(s):

Wastewater Treatment ◽

Constructed Wetland ◽

Municipal Wastewater ◽

Free Water ◽

Avicennia Marina ◽

Pilot Scale ◽

Natural Forest ◽

Municipal Wastewater Treatment ◽

Detention Time ◽

Bruguiera Cylindrica

The study evaluated the possibility of using mangrove plantation to treat municipal wastewater. Two types of pilot scale (100 × 150 m2) free water surface constructed wetland were set up. One system was a natural Avicennia marina dominated forest system. The other system was a newly planted system in which seedlings of Rhizophora spp., A. marina, Bruguiera cylindrica and Ceriops tagal were planted in 4 strips. Municipal wastewater was retained within the systems for 7 and 3 days, respectively. The results indicated that the average removal percentage of TSS, BOD, NO3-N, NH4-N, TN, PO4-P and TP in the newly planted system were 27.6-77.1, 43.9-53.9, 37.6-47.5, 81.1-85.9, 44.8-54.4, 24.7-76.8 and 22.6-65.3, respectively. Whereas the removal percentage of those parameters in the natural forest system were 17.1-65.9, 49.5-51.1, 44.0-60.9, 51.1-83.5, 43.4-50.4, 28.7-58.9 and 28.3-48.0, respectively. Generally, the removal percentages within the newly planted system and the natural forest system were not significantly different. However, when the removal percentages were compared with detention time, TSS, PO4-P and TP percentages removed were significantly higher in the 7-day detention time treatment. Even though the removal percentages were highly varied and temporally dependent, the overall results showed that mangrove plantation could be used as constructed wetland for municipal wastewater treatment in a similar way to the natural mangrove system.

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Treatment of oil sands process-affected waters using a pilot-scale hybrid constructed wetland

Ecological Engineering ◽

10.1016/j.ecoleng.2018.02.009 ◽

2018 ◽

Vol 115 ◽

pp. 45-57 ◽

Cited By ~ 7

Author(s):

Maas Hendrikse ◽

Daniel P. Gaspari ◽

Andrew D. McQueen ◽

Ciera M. Kinley ◽

Alyssa J. Calomeni ◽

...

Keyword(s):

Constructed Wetland ◽

Oil Sands ◽

Pilot Scale

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Pollutant removal and growth dynamics of macrophyte species for faecal sludge treatment with constructed wetland technology

Water Science & Technology ◽

10.2166/wst.2019.354 ◽

2019 ◽

Vol 80 (6) ◽

pp. 1145-1154

Author(s):

Agyemang Richard Osei ◽

Yacouba Konate ◽

Felix Kofi Abagale

Keyword(s):

Constructed Wetland ◽

Growth Parameters ◽

Oxygen Demand ◽

Growth Dynamics ◽

Pilot Scale ◽

Pollutant Removal ◽

Local Context ◽

Organic Chemical ◽

Bambusa Vulgaris ◽

Faecal Sludge

Abstract Constructed wetland technology is an innovative engineering technique for faecal sludge (FS) management. The presence of emergent macrophytes enhances the important processes of evapotranspiration, sludge mineralisation, and contaminant reduction. Consequently, selecting a species that can withstand the difficult sludge contaminated conditions within a local context is vital. This study monitored the pollutant removal potentials and growth dynamics of Bambusa vulgaris and Cymbopogon nardus as promising macrophytes for the constructed wetland technology in the Sudano-Sahelian context. The experiment, at pilot scale, consisted of plastic reactors (27 litre) filled with filter media of sand and fine gravels at the base, and planted with the selected species. Pollutant removal efficiencies were evaluated based on differences between influent and effluent concentrations, and physiological growth parameters of plant height, number of leaves and number of plants were monitored monthly. Total annual sludge loading rate of 31.4 and 103.4 kg TS/(m2·yr) (TS: total solids) were determined for FS + wastewater (acclimatisation phase) and FS load respectively. Both species recorded appreciable pollutant removal efficiency >80% for the organic (chemical oxygen demand), nutrients (PO43_P and NH4-N) and solid (total suspended solids and total volatile solids) contents. The species thus demonstrated satisfactory performance of resistance for faecal polluted wetland conditions.

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