Lead phytoextraction from contaminated soil with high-biomass plant species.

In this study, cabbage [Brassica rapa L. subsp. chinensis (L.) Hanelt cv. Xinza No 1], mung bean [Vigna radiata (L.) R. Wilczek var. radiata cv. VC-3762], and wheat (Triticum aestivum L. cv. Altas 66) were grown in Pb-contaminated soils. Application of ethylenediaminetetraacetic acid (EDTA) (3.0 mmol of EDTA/kg soil) to the soil significantly increased the concentrations of Pb in the shoots and roots of all the plants. Lead concentrations in the cabbage shoots reached 5010 and 4620 mg/kg dry matter on Days 7 and 14 after EDTA application, respectively. EDTA was the best in solubilizing soil-bound Pb and enhancing Pb accumulation in the cabbage shoots among various chelates (EDTA, diethylenetriaminepentaacetic acid [DTPA], hydroxyethylenediaminetriacetic acid [HEDTA], nitrilotriacetic acid [NTA], and citric acid). Results of the sequential chemical extraction of soil samples showed that the Pb concentrations in the carbonate-specifically adsorbed and Fe-Mn oxide phases were significantly decreased after EDTA treatment. The results indicated that EDTA solubilized Pb mainly from these two phases in the soil. The relative efficiency of EDTA enhancing Pb accumulation in shoots (defined as the ratio of shoot Pb concentration to EDTA concentration applied) was highest when 1.5 or 3.0 mmol EDTA/kg soil was used. Application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.

[1]  S. McGrath,et al.  Uptake and transport of zinc in the hyperaccumulator Thlaspi caerulescens and the non‐hyperaccumulator Thlaspi ochroleucum , 1997 .

[2]  S. K. Gupta,et al.  Enhancement of phytoextraction of Zn, Cd, and Cu from calcareous soil: The use of NTA and sulfur amendments , 2000 .

[3]  R. Chaney,et al.  Free metal activity and total metal concentrations as indices of micronutrient availability to barley [Hordeum vulgare (L.) ‘Klages’] , 2004, Plant and Soil.

[4]  B. Jones,et al.  Distribution and speciation of heavy metals in surficial sediments from the Tees Estuary, north-east England , 1997 .

[5]  S. D. Cunningham,et al.  Chelate-Assisted Pb Phytoextraction: Pb Availability, Uptake, and Translocation Constraints , 1999 .

[6]  I. Thornton,et al.  Chemical partitioning of trace and major elements in soils contaminated by mining and smelting activities , 2001 .

[7]  B. Ensley,et al.  Phytoremediation of Uranium-Contaminated Soils: Role of Organic Acids in Triggering Uranium Hyperaccumulation in Plants , 1998 .

[8]  R. Kamath,et al.  Use of isotopic dilution techniques to assess the mobilization of nonlabile Cd by chelating agents in phytoremediation. , 2000 .

[9]  Ilya Raskin,et al.  Phytoextraction: the use of plants to remove heavy metals from soils. , 1995, Environmental science & technology.

[10]  M. McBride.  Environmental Chemistry of Soils , 1994 .

[11]  W. Norwood,et al.  EDTA toxicity and background concentrations of copper and zinc in Hyalella azteca , 1995 .

[12]  B. Clothier,et al.  Soil Amendments Affecting Nickel and Cobalt Uptake by Berkheya coddii : Potential Use for Phytomining and Phytoremediation , 1999 .

[13]  D. Crerar,et al.  Relative degradation rates of NTA, EDTA and DTPA and environmental implications , 1980 .

[14]  Sally Brown,et al.  Phytoremediation of soil metals. , 1997, Current opinion in biotechnology.

[15]  T. E. Staley,et al.  A Rapid Centrifugation Method for Obtaining Soil Solution , 1987 .

[16]  A. Tessier,et al.  Sequential extraction procedure for the speciation of particulate trace metals , 1979 .

[17]  Stephen D. Ebbs,et al.  Phytoextraction of Zinc by Oat (Avena sativa), Barley (Hordeum vulgare), and Indian Mustard (Brassica juncea) , 1998 .

[18]  H. F. Mayland,et al.  Selenium uptake by plants from soils amended with inorganic and organic materials , 1998 .

[19]  Ilya Raskin,et al.  Enhanced Accumulation of Pb in Indian Mustard by Soil-Applied Chelating Agents , 1997 .

[20]  S. McGrath,et al.  Comparison of three wet digestion methods for the determination of plant sulphur by inductively coupled plasma atomic emission spectroscopy (ICP‐AES) , 1994 .

[21]  S. D. Cunningham,et al.  Lead phytoextraction: species variation in lead uptake and translocation , 1996 .

[22]  I. Raskin,et al.  Bioconcentration of heavy metals by plants , 1994 .

[23]  D. Kinniburgh,et al.  Adsorption of alkaline earth transition and heavy metal cations by hydrous oxide gels of iron and aluminum , 1976 .

[24]  B. Nörtemann.  Biodegradation of EDTA , 1999, Applied Microbiology and Biotechnology.

[25]  V. Ramachandran,et al.  Influence of chelating agents on plant uptake of 51Cr, 210Pb and 210Po , 1995 .

[26]  Scott D. Cunningham,et al.  Phytoremediation of Lead-Contaminated Soils: Role of Synthetic Chelates in Lead Phytoextraction , 1997 .

[27]  Raskin,et al.  The role of EDTA in lead transport and accumulation by indian mustard , 1998, Plant physiology.

[28]  Uri Yermiyahu,et al.  EDTA and Pb—EDTA accumulation in Brassica juncea grown in Pb—amended soil , 1999, Plant and Soil.

[29]  L. Ramos,et al.  Sequential Fractionation of Copper, Lead, Cadmium and Zinc in Soils from or near Doñana National Park , 1994 .

[30]  R. Rubio,et al.  Trace metal partitioning in marine sediments and sludges deposited off the coast of Barcelona (Spain) , 1996 .

[31]  Michael H. Ramsey,et al.  Sequential extraction of soils for multielement analysis by ICP-AES , 1995 .

[32]  B. Kos,et al.  EDTA enhanced heavy metal phytoextraction: metal accumulation, leaching and toxicity , 2001, Plant and Soil.

[33]  L. Ma,et al.  CHEMICAL FRACTIONATION OF CADMIUM, COPPER, NICKEL, AND ZINC IN CONTAMINATED SOILS , 1997 .

[34]  Yuncong C. Li,et al.  Chemical Association of Cu, Zn, Mn, and pb in Selected Sandy Citrus Soils , 1997 .

[35]  A. K. Davis,et al.  Micromineralogy of mine wastes in relation to lead bioavailability, Butte, Montana , 1993 .

[36]  S. McGrath,et al.  The Potential for the Use of Metal-Accumulating Plants for the in Situ Decontamination of Metal-Polluted Soils , 1993 .

[37]  V. Römheld,et al.  Effect of Fe stress on utilization of Fe chelates by efficient and inefficient plant species , 1981 .

[38]  Peter E. Body M. App. Sc.,et al.  Environmental lead: A review , 1991 .

[39]  B. Mackey,et al.  Evaluation of different plant species used for phytoremediation of high soil selenium , 1997 .

[40]  L. Kochian,et al.  Molecular physiology of zinc transport in the Zn hyperaccumulator Thlaspi caerulescens. , 2000, Journal of experimental botany.