title: Accumulation and Distribution of Lead and Chromium in Laboratory-Scale Constructed Wetlands Inoculated with Metal-Tolerant Bacteria.
abstract: The accumulation and distribution of lead and chromium was tested in a laboratory-scale constructed wetland (CW) inoculated with metal-tolerant bacteria. Two non-inoculated systems also were evaluated, one planted and the other unplanted. Mass balances indicated that 57% of chromium input was accumulated into inoculated CW after 151 days of operation. The distribution was similar in support media and vegetation, in which 78% was transferred to aerial part. Similarly Pb was accumulated 29% in the support media and 39% in vegetation, which was distributed 52% in rhizome and 48% in aerial part. Significantly lower amounts of heavy metals were accumulated in non-inoculated systems than in the inoculated wetlands (p < 0.005). In addition, a markedly higher proportion of chromium in aerial vegetation and of lead in the suspended fraction of the effluent was exhibited, which raises a subsequent recovery of the metal by harvest and settling, respectively. Results indicate that CW inoculated with metal-tolerant bacteria might be a suitable option for treating wastewater with content of lead and chromium.
authors.affiliation: a Facultad de Química, Universidad Nacional Autónoma de México , Ciudad de México , D.F. , México.
authors.forename: Leonel E
authors.initials: LE
authors.lastname: Amabilis-Sosa
authors.forename: Christina
authors.initials: C
authors.lastname: Siebe
authors.forename: Gabriela
authors.initials: G
authors.lastname: Moeller-Chávez
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Durán-Domínguez-de-Bazúa
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D007854:Lead / Q000378:metabolism*; D059013:Microbial Consortia; D006109:Poaceae / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; D007854:Lead
keywords: Phragmites australis; biofilm; heavy metals; mass balance; support media