A phytogeochemical study of the Trás-os-Montes region (NE Portugal): Possible species for plant-based soil remediation technologies

• Published in: The Science of the total environment Vol. 354; no. 2; pp. 265 - 277
• Main Authors: Díez Lázaro, J., Kidd, P.S., Monterroso Martínez, C.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 01.02.2006; Elsevier Science
• Subjects: Alyssum; Applied sciences; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; Cistus ladanifer; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Geological Phenomena; Geology; Heavy metal accumulation; Industrial applications and implications. Economical aspects; Lavandula; Magnoliopsida - metabolism; Metal bioavailability; Metals, Heavy - analysis; Metals, Heavy - metabolism; Miscellaneous; Phytoremediation; Plant Leaves - chemistry; Plant Leaves - metabolism; Plant Roots - chemistry; Plant Roots - metabolism; Plant Stems - chemistry; Plant Stems - metabolism; Plantago; Pollution; Pollution, environment geology; Portugal; Soil and sediments pollution; Soil Pollutants - analysis; Soil Pollutants - metabolism; Thymus; Ultramafic soils; Portugal; Europe; Metal bioavailability; Ultramafic soils; Heavy metal accumulation; Phytoremediation; Interspecific comparison; Bioavailability; Soil pollution; Phytoextraction; Heavy metal; Decontamination; Hyperaccumulator; Bioremediation; Biological accumulation; Performance
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2005.01.001

Phytoremediation techniques are now considered to be promising alternatives to conventional techniques for the remediation of diffused or moderately contaminated soils. Despite their growing acceptance relatively few plant species have been studied for phytoremediation purposes. Further geobotanical surveys and plant screenings are necessary since these could lead to the identification of additional species with potential value for such applications. Serpentine areas could prove valuable sources of such plants. In this study heavy metal accumulation was determined in the flora associated with ultramafic and non-ultramafic soils of the Trás-os-Montes region of NE Portugal. Study sites were selected to represent a wide range of soil-forming rocks (serpentinized (S), ultrabasic (UB), basic (B) and acid (migmatite, M and schists, SC) rocks) and plant metal accumulation was related to soil metal bioavailability. Nine plant species (representing 7 families) were sampled including the Ni hyperaccumulator Alyssum serpyllifolium subsp. lusitanicum. The greatest metal accumulation, transport (leaf [metal]:root [metal]) and bioaccumulation (leaf [metal]/soil [metal]) was found in four of the non metal-hyperaccumulating species: Cistus ladanifer, Lavandula stoechas, Plantago subulata subsp. radicata and Thymus mastichina. Metal accumulation depended on both the plant species and the edaphic conditions at its provenance. While P. subulata is of less interest due to its low biomass the remaining three species could be of use in phytoremediation technologies such as phytoextraction, and particularly in soils contaminated with Cr, Mn and Zn. These three species are also of economic interest due to their oil and fragrance producing biomass.