Using one filter stage of unsaturated/saturated vertical flow filters for nitrogen removal and footprint reduction of constructed wetlands

French vertical flow constructed wetlands (VFCW) treating raw wastewater have been developed successfully over the last 30 years. Nevertheless, the two-stage VFCWs require a total filtration area of 2-2.5 m2/P.E. Therefore, implementing a one-stage system in which treatment performances reach standa...

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Veröffentlicht in:Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 76(2017), 1-2 vom: 16. Juli, Seite 124-133
1. Verfasser: Morvannou, Ania (VerfasserIn)
Weitere Verfasser: Troesch, Stéphane, Esser, Dirk, Forquet, Nicolas, Petitjean, Alain, Molle, Pascal
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2017
Zugriff auf das übergeordnete Werk:Water science and technology : a journal of the International Association on Water Pollution Research
Schlagworte:Evaluation Study Journal Article Waste Water Nitrogen N762921K75
Beschreibung
Zusammenfassung:French vertical flow constructed wetlands (VFCW) treating raw wastewater have been developed successfully over the last 30 years. Nevertheless, the two-stage VFCWs require a total filtration area of 2-2.5 m2/P.E. Therefore, implementing a one-stage system in which treatment performances reach standard requirements is of interest. Biho-Filter® is one of the solutions developed in France by Epur Nature. Biho-Filter® is a vertical flow system with an unsaturated layer at the top and a saturated layer at the bottom. The aim of this study was to assess this new configuration and to optimize its design and operating conditions. The hydraulic functioning and pollutant removal efficiency of three different Biho-Filter® plants commissioned between 2011 and 2012 were studied. Outlet concentrations of the most efficient Biho-Filter® configuration are 70 mg/L, 15 mg/L, 15 mg/L and 25 mg/L for chemical oxygen demand (COD), 5-day biological oxygen demand (BOD5), total suspended solids (TSS) and total Kjeldahl nitrogen (TKN), respectively. Up to 60% of total nitrogen is removed. Nitrification efficiency is mainly influenced by the height of the unsaturated zone and the recirculation rate. The optimum recirculation rate was found to be 100%. Denitrification in the saturated zone works at best with an influent COD/NO3-N ratio at the inflet of this zone larger than 2 and a hydraulic retention time longer than 0.75 days
Beschreibung:Date Completed 11.01.2018
Date Revised 07.12.2022
published: Print
Citation Status MEDLINE
ISSN:0273-1223
DOI:10.2166/wst.2017.115