title: Uranium accumulation in aquatic macrophytes in an uraniferous region: Relevance to natural attenuation.
abstract: Phytoremediation potential of uranium (U) was investigated by submerged, free-floating and rooted emergent native aquatic macrophytes inhabiting along the streams of Horta da Vilariça, a uraniferous geochemical region of NE Portugal. The work has been undertaken with the following objectives: (i) to relate the U concentrations in water-sediment-plant system; and (ii) to identify the potentialities of aquatic plants to remediate U-contaminated waters based on accumulation pattern. A total of 25 plant species culminating 233 samples was collected from 15 study points along with surface water and contiguous sediments. Concentrations of U showed wide range of variations both in waters (0.61-5.56 μg L(-1), mean value 1.98 μg L(-1)) and sediments (124-23,910 μg kg(-1), mean value 3929 μg kg(-1)) and this is also reflected in plant species examined. The plant species exhibited the ability to accumulate U several orders of magnitude higher than the surrounding water. Maximum U concentrations was recorded in the bryophyte Scorpiurium deflexifolium (49,639 μg kg(-1)) followed by Fontinalis antipyretica (35,771 μg kg(-1)), shoots of Rorippa sylvestris (33,837 μg kg(-1)), roots of Oenanthe crocata (17,807 μg kg(-1)) as well as in Nasturtium officinale (10,995 μg kg(-1)). Scorpiurium deflexifolium displayed a high bioconcentration factor (BF) of ∼2.5 × 10(4) (mean value). The species Fontinalis antipyretica, Nasturtium officinale (roots) and Rorippa sylvestris (shoots) exhibited the mean BFs of 1.7 × 10(4), 5 × 10(3) and 4.8 × 10(3) respectively. Maximum translocation factor (TF) was very much pronounced in the rooted perennial herb Rorippa sylvestris showing extreme ability to transport U for the shoots and seems to be promising candidate to be used as bioindicator species.
authors.affiliation: MARE, Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517, Coimbra, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Cordeiro
authors.affiliation: MARE, Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517, Coimbra, Portugal; University of Trás-os-Montes e Alto Douro, UTAD, School of Life Sciences and the Environment, Quinta de Prados, 5000-801, Vila Real, Portugal. Electronic address: pjcf@utad.pt.
authors.forename: Paulo J C
authors.initials: PJC
authors.lastname: Favas
authors.affiliation: MARE, Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517, Coimbra, Portugal; University of Coimbra, Faculty of Sciences and Technology, Department of Earth Sciences, 3001-401, Coimbra, Portugal; Instituto de Geologia e Petróleo de Timor Leste, Timor Leste.
authors.forename: João
authors.initials: J
authors.lastname: Pratas
authors.affiliation: University of Calcutta, Department of Marine Science, 35, Ballygunge Circular Road, Calcutta, 700019, West Bengal, India.
authors.forename: Santosh Kumar
authors.initials: SK
authors.lastname: Sarkar
authors.affiliation: Periyar University, Department of Biotechnology, Salem, 636 011, TN, India.
authors.forename: Perumal
authors.initials: P
authors.lastname: Venkatachalam
mesh_terms: D001673:Biodegradation, Environmental; D044002:Bryophyta / Q000378:metabolism; D019068:Bryopsida / Q000378:metabolism; D004784:Environmental Monitoring; D031223:Nasturtium / Q000378:metabolism; D031050:Oenanthe / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D011174:Portugal; D045483:Rivers / Q000737:chemistry; D031225:Rorippa / Q000378:metabolism; D014501:Uranium / Q000032:analysis / Q000378:metabolism*; D014875:Water Pollutants, Radioactive / Q000032:analysis / Q000378:metabolism*
chemical_list: D014875:Water Pollutants, Radioactive; D014501:Uranium
keywords: Bioaccumulation; Horta da vilariça; Phytoextraction; Phytofiltration; Phytostabilization; Uranium biogeochemistry