Changes in metal mobility assessed by EDTA kinetic extraction in three polluted soils after repeated phytoremediation using a cadmium/zinc hyperaccumulator.

Title Changes in metal mobility assessed by EDTA kinetic extraction in three polluted soils after repeated phytoremediation using a cadmium/zinc hyperaccumulator.
Authors Z. Li; L. Wu; Y. Luo; P. Christie
Journal Chemosphere
DOI 10.1016/j.chemosphere.2017.12.005
Abstract

Phytoextraction is one of the most promising technologies for the decontamination of metal-polluted agricultural soils. Effects of repeated phytoextraction by the cadmium (Cd)/zinc (Zn) hyperaccumulator Sedum plumbizincicola on metal (Cd, Zn, copper (Cu) and lead (Pb)) mobility were investigated in three contaminated soils with contrasting properties. EDTA kinetic extraction and the two first-order reactions model showed advantages in the assessment of soil metal mobility and clearly discriminated changes in metal fractions induced by phytoextraction. Repeated phytoextraction led to large decreases in readily labile (Q10) and less labile (Q20) fractions of Cd and Zn in all three soils with the sole exception of an increase in the Q20 of Zn in the highly polluted soil. However, Q10 fractions of soil Cu and Pb showed apparent increases with the sole exception of Pb in the acid polluted soil but showed a higher desorption rate constant (k1). Furthermore, S. plumbizincicola decreased the non-labile fraction (Q30) of all metals tested, indicating that the hyperaccumulator can redistribute soil metals from non-labile to labile fractions. This suggests that phytoextraction decreased the mobility of the metals hyperaccumulated by the plant (Cd and Zn) but increased the mobility of the metals not hyperaccumulated (Cu and Pb). Thus, phytoextraction of soils contaminated with mixtures of metals must be performed carefully because of potential increases in the mobility of non-hyperaccumulated metals in the soil and the consequent environmental risks.

Citation Z. Li; L. Wu; Y. Luo; P. Christie.Changes in metal mobility assessed by EDTA kinetic extraction in three polluted soils after repeated phytoremediation using a cadmium/zinc hyperaccumulator.. Chemosphere. 2018;194:432440. doi:10.1016/j.chemosphere.2017.12.005

Related Elements

Cadmium

See more Cadmium products. Cadmium (atomic symbol: Cd, atomic number: 48) is a Block D, Group 12, Period 5 element with an atomic weight of 112.411. Cadmium Bohr ModelThe number of electrons in each of Cadmium's shells is 2, 8, 18, 18, 2 and its electron configuration is [Kr]4d10 5s2. The cadmium atom has a radius of 151 pm and a Van der Waals radius of 230 pm. Cadmium was discovered and first isolated by Karl Samuel Leberecht Hermann and Friedrich Stromeyer in 1817. In its elemental form, cadmium has a silvery bluish gray metallic appearance. Cadmium makes up about 0.1 ppm of the earth's crust. Elemental CadmiumNo significant deposits of cadmium containing ores are known, however, it is sometimes found in its metallic form. It is a common impurity in zinc ores and is isolated during the production of zinc. Cadmium is a key component in battery production and particular pigments and coatings due to its distinct yellow color. Cadmium oxide is used in phosphors for television picture tubes. The name Cadmium originates from the Latin word 'cadmia' and the Greek word 'kadmeia'.

Zinc

See more Zinc products. Zinc (atomic symbol: Zn, atomic number: 30) is a Block D, Group 12, Period 4 element with an atomic weight of 65.38. The number of electrons in each of zinc's shells is 2, 8, 18, 2, and its electron configuration is [Ar] 3d10 4s2. Zinc Bohr ModelThe zinc atom has a radius of 134 pm and a Van der Waals radius of 210 pm. Zinc was discovered by Indian metallurgists prior to 1000 BC and first recognized as a unique element by Rasaratna Samuccaya in 800. Zinc was first isolated by Andreas Marggraf in 1746. In its elemental form, zinc has a silver-gray appearance. It is brittle at ordinary temperatures but malleable at 100 °C to 150 °C.Elemental Zinc It is a fair conductor of electricity, and burns in air at high red producing white clouds of the oxide. Zinc is mined from sulfidic ore deposits. It is the 24th most abundant element in the earth's crust and the fourth most common metal in use (after iron, aluminum, and copper). The name zinc originates from the German word "zin," meaning tin.