کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4424271 1619164 2016 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Changes in metal availability, desorption kinetics and speciation in contaminated soils during repeated phytoextraction with the Zn/Cd hyperaccumulator Sedum plumbizincicola
ترجمه فارسی عنوان
تغییرات در دسترسی فلزی، سینتیک جداسازی و گونه زایی در خاک های آلوده در طول استخراج گیاهی مکرر با plumbizincicola گل ناز Zn/Cd hyperaccumulator
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
چکیده انگلیسی


• Metal availability, desorption, and speciation were tested during phytoextraction.
• Metal availability showed an initial sharp decline then a slight change in acid soils.
• Metal availability changed little during phytoextraction in calcareous soils.
• Metal desorption rate constant showed a large decline, especially in calcareous soils.
• Non-available metal fractions can also be extracted by the hyperaccumulator.

Phytoextraction is one of the most promising technologies for the remediation of metal contaminated soils. Changes in soil metal availability during phytoremediation have direct effects on removal efficiency and can also illustrate the interactive mechanisms between hyperaccumulators and metal contaminated soils. In the present study the changes in metal availability, desorption kinetics and speciation in four metal-contaminated soils during repeated phytoextraction by the zinc/cadmium hyperaccumulator Sedum plumbizincicola (S. plumbizincicola) over three years were investigated by chemical extraction and the DGT-induced fluxes in soils (DIFS) model. The available metal fractions (i.e. metal in the soil solution extracted by CaCl2 and by EDTA) decreased greatly by >84% after phytoextraction in acid soils and the deceases were dramatic at the initial stages of phytoextraction. However, the decreases in metal extractable by CaCl2 and EDTA in calcareous soils were not significant or quite low. Large decreases in metal desorption rate constants evaluated by DIFS were found in calcareous soils. Sequential extraction indicated that the acid-soluble metal fraction was easily removed by S. plumbizincicola from acid soils but not from calcareous soils. Reducible and oxidisable metal fractions showed discernible decreases in acid and calcareous soils, indicating that S. plumbizincicola can mobilize non-labile metal for uptake but the residual metal cannot be removed. The results indicate that phytoextraction significantly decreases metal availability by reducing metal pool sizes and/or desorption rates and that S. plumbizincicola plays an important role in the mobilization of less active metal fractions during repeated phytoextraction.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Environmental Pollution - Volume 209, February 2016, Pages 123–131
نویسندگان
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