title: Purification processes involved in sludge treatment by a vertical flow wetland system: focus on the role of the substrate and plants on N and P removal.
abstract: Vertical-flow wetland systems were tested for treatment of liquid waste activated sludge with high content of organic compounds from a soft drink factory. A mesocosm experiment was carried out on planted and unplanted systems to understand the relative importance of substrate and plants in purification processes and to compare three species: Phragmites australis Cav., Typha latifolia L., or Iris pseudacorus L. All planted mesocosms performed better than unplanted mesocosms and Phragmites showed the highest efficiencies, both in volumes and loads, closely followed by Typha. Removal efficiencies were very high in all cases, and physical filtration by the organic substrate was identified as the main processes for nutrient removal (>50%). We showed that plants played direct and indirect roles such as nutrients uptake (up to 23% of the N for Phragmites), evapotranspiration reducing outflow volumes; or improvement of filtration by the root systems and stimulation of microbial activities (respiration rate was double compared to unplanted mesocosms).
authors.affiliation: Aix-Marseille Université, IMEP - Institut Méditerranéen d'Ecologie et de Paléoécologie (UMR CNRS 6116) - Diversité Fonctionnelle des Communautés Végétales, Centre Saint Charles - case 4-3 place Victor Hugo, F-13331 Marseille, cedex 03, France. nathalie.korboulewsky@cemagref.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Korboulewsky
authors.forename: Runying
authors.initials: R
authors.lastname: Wang
authors.forename: Virginie
authors.initials: V
authors.lastname: Baldy
mesh_terms: D018533:Biomass; D001709:Biotechnology / Q000379:methods; D002244:Carbon / Q000737:chemistry; D004867:Equipment Design; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D007498:Iris / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D018521:Plant Physiological Phenomena; D018517:Plant Roots; D010944:Plants / Q000378:metabolism; D015203:Reproducibility of Results; D012119:Respiration; D012722:Sewage / Q000737:chemistry*; D032401:Typhaceae / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D012722:Sewage; D002244:Carbon; D009584:Nitrogen