Uptake and fixation of Zn, Pb, and Cd by Thlaspi caerulescens: application in the cases of old mines of Mibladen and Zaida (West of Morocco)

Abstract

Contaminated soils and mine tailings pose major environmental and agricultural problems worldwide. These problems may be partially solved by an emerging new technology: phytoremediation. This technique uses plants to extract soil contaminants from the ground. Thlaspi caerulescens is known to accumulate in their tissues several heavy metals from soil and aerial deposition. This study was conducted to screen plants growing on a contaminated site to determine their potential for metal accumulation. Seeds of T. caerulescens metallicolous have been collected in the vicinity of F.T. Laurent le Minier in the Pb-Zn mining district of les Malines (North of Montpellier, Southern France), and seeds of T. caerulescens nonmetallicolous were sampled on Larzac Plateau (North of Montpellier, Southern France). Soil substrates were collected from a mine site of Mibladen and Zaida (West, Morroco). Cultivated plant and surface soil samples were analyzed for zinc, lead, and cadmium concentrations by inductively coupled plasma mass spectrometry. A non-metallicolous (NM) ecotype of T. caerulescens and a metallicolous (M) ecotype are compared for Pb, Cd, and Zn accumulation in shoot and root in five metal-contaminated soils and one uncontaminated soil. The growth of individuals from uncontaminated soil was greater than that of individuals from metal-contaminated soils. The NM populations had markedly higher root/shoot ratio compared to M populations. The results indicate that both ecotypes of T.caerulescens are highly tolerant of zinc and Cd. Ecotype NM had constitutively higher Zn uptake capacity than the M ecotype. T. caerulescens species accumulate higher amount of Zn and Cd in their tissues in polluted soil and, in both of the two ecotypes, the root Pb concentrations were much greater than those of the shoot Pb contents. From both uncontaminated and metal-contaminated soils, we conclude that T. caerulescens are interesting material for phytoremediation of zinc and cadmium.

The long-term variation of Cd and Zn hyperaccumulation byNoccaea sppandArabidopsis halleriplants in both pot and field conditions

“…However, another species from the Noccaea genus, N. rotundifolia, is considered to be a Pb hyperaccumulator, with a maximum Pb level in shoots of 8200 mg kg -1 was reported by Reeves and Brooks (1983). However, the predominant Pb accumulation in the roots of both N. rotundifolia and N. caerulescens was shown in both soil and solution experiments (Huang and Cunningham 1996, El Kheir et al 2008, Banasova et al 2008. The potential estimation of the phytoextraction efficiency of the hyperaccumulating plants based on one-off nutrient solution experiments or soil pot experiments is questionnable.…”

Iron Heterogeneity in Soil and its Relation to its Uptake by Water Leaf (Talinum Triangulaire L.)

“…"Several terms have been used in different studies. In certain studies, concentration factor is also known as phytoextraction or bioaccumulation factor" [18,19]. "It is estimated as the ratio of trace metal concentrations in the aerial + below-ground part of plants and soil trace metal concentration (both expressed on a dry weight (DW) basis), and expressed mathematically" [15].…”

Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling

“…This is particularly clear for Zeida (Figure 5a). Iron hydroxides sorb lead onto strong (s) and weak (w) sorption sites, referred to as ≡Hfo_sOH and ≡Hfo_wOH, respectively: ≡Hfo_sOH + Pb 2+ ⇔ ≡Hfo_sOPb + + H + (12) ≡Hfo_wOH + Pb 2+ ⇔ ≡Hfo_wOPb + + H + (13) ≡Hfo_sOH ⇔ ≡Hfo_sO − + H + (14) ≡Hfo_wOH ⇔ ≡Hfo_wO − + H + (15) When present in the solid phase, iron hydroxides can sorb lead. Conversely, they release the sorbed lead when they dissolve.…”

“…They are also used as uncontrolled construction materials: finishing and surfacing mortar for residential walls [1,7,8]. After the cessation of operations, this mining waste significantly contaminated water resources and adjacent soils [9][10][11][12]. Indeed, in addition to the substantial contamination of surface waters and soils, the weathering of this waste triggers the release of some pollutants, including toxic trace metals, e.g., [13][14][15].…”