Kinetic extractions to assess mobilization of Zn, Pb, Cu, and Cd in a metal-contaminated soil: EDTA vs. citrate

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• 作者：Jé ; rô ; me Labanowski ; Fabrice Monna ; Alain Bermond ; Philippe Cambier ; Christelle Fern ; ez ; Isabelle Lamy ; Folkert van Oort
• 关键词：Kinetic extraction modeling ; Heavy metals ; EDTA ; Citrate ; Metal mobility ; Soils
• 刊名：Environmental Pollution
• 出版年：2008
• 出版时间：April 2008
• 年：2008
• 卷：152
• 期：3
• 页码：693-701
• 全文大小：402 K

文摘

Kinetic EDTA and citrate extractions were used to mimic metal mobilization in a soil contaminated by metallurgical fallout. Modeling of metal removal rates vs. time distinguished two metal pools: readily labile (Q_M1) and less labile (Q_M2). In citrate extractions, total extractability (Q_M1 + Q_M2) of Zn and Cd was proportionally higher than for Pb and Cu. Proportions of Pb and Cu extracted with EDTA were three times higher than when using citrate. We observed similar Q_M1/Q_M2 ratios for Zn and Cu regardless of the extractant, suggesting comparable binding energies to soil constituents. However, for Pb and Cd, more heterogeneous binding energies were hypothesized to explain different kinetic extraction behaviors. Proportions of citrate-labile metals were found consistent with their short-term, in-situ mobility assessed in the studied soil, i.e., metal amount released in the soil solution or extracted by cultivated plants. Kinetic EDTA extractions were hypothesized to be more predictive for long-term metal migration with depth.