title: Tracing sewage water by 15N in a mangrove ecosystem to test its bioremediation ability.
abstract: Mangrove forests could be a simple and effective alternative to conventional sewage treatment, particularly for island communities given its low cost and low maintenance. Due to their high adaptation capacity, these plants are able to tolerate and bioremediate the high levels of nutrients and pollutants found in sewage water. This solution could be applied to small tropical islands with high population density such as Mayotte in the Indian Ocean. This paper reports on a trial by stable isotopic (15)N tracing of such a bioremediation process on pre-treated wastewater near the village of Malamani, in the middle of the large coastal mangrove in the bay near Chirongui. The first results show a boost in the mangrove growth, but a longer period of observation is needed to confirm the beneficial effects, and also to clarify the role of the local crab population, whose engineering activities play an important part in the ecosystem. The exact denitrification process is not yet understood, and the mass balance equation also reveals loss of nitrogen-containing compounds, which needs to be analyzed more closely.
authors.affiliation: Université de Toulouse, INP, UPS, EcoLab, 118 route de Narbonne, 31062 Toulouse Cedex 9, France. lambs@cict.fr
authors.forename: Luc
authors.initials: L
authors.lastname: Lambs
authors.forename: Audrey
authors.initials: A
authors.lastname: Léopold
authors.forename: Bernd
authors.initials: B
authors.lastname: Zeller
authors.forename: Mélanie
authors.initials: M
authors.lastname: Herteman
authors.forename: Francois
authors.initials: F
authors.lastname: Fromard
mesh_terms: D001673:Biodegradation, Environmental; D017507:Comoros; D058440:Denitrification; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry; D006813:Humidity; D019156:Indian Ocean; D013058:Mass Spectrometry; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D009587:Nitrogen Isotopes / Q000032:analysis; D000644:Quaternary Ammonium Compounds; D043982:Rhizophoraceae / Q000378:metabolism*; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D009587:Nitrogen Isotopes; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D012987:Soil; D014867:Water; D009584:Nitrogen