以植生復育法處理重金屬污染底泥之探討

Phytoextraction of Soil Metal Enhancing by Chelator

葉琮裕(T. Y. Yeh)

《臺灣鑛業》 63卷4期 (2011/12) Pp. 28-43

https://doi.org/10.30014/TMI.201112.0005

摘要

Growth and metal-accummulation of Vetiveria zizanioides exposed to Cu, Zn, Pb and Cr-contaminated sediment were examined and the effect of chelator addition including EDDS, citric acid, EDTA and humic acid on phytoextraction of metals were also investigated in the hydroponic and pot experiments. In the hydroponic test, citric acid and humic acid enhanced the Cu, Zn, Pb and Cr levels in the roots of vetiver compared to EDDS and EDTA. EDTA induced the significant toxic effect owing to EDTA has complex ability leading less free metal ions. Despite of the toxic effect, the aerial plant parts translocation was viable compared to control. In pot experiment, the sequential extraction results showed that the mobility of Cu and Zn were higher than Pb and Cr. After adding EDDS and EDTA, it increased the loosely bound metals relative to control that indicated that sediment Cu, Zn, Pb and Cr mobility were enhanced. And the citric acid could enhance the mobility of Cr to improve the bioavailable of heavy metals. Phytoremediation efficiency factor (PEF) of vetiver were Zn ＞ Cu ＞ Pb ＞ Cr. After adding EDDS, the PEF of Cu, Pb and Cr increased 23, 7.5 and 2 folds relative to the control. For Cu, Zn, Pb and Cr, EDTA was by 31, 3.7, 19, 3 times, compared to the control PEF value. And the citric acid could increase 2 and 3.4 folds relative to the control of Cu and Cr PEF value. Adding humic aicd could not improve the phytoextraction of vetiver grass, but it could enhance the accumulation of Pb in roots.

關鍵字

培地茅 ； 底泥 ； 植生復育法 ； 蟄何劑

並列摘要

Growth and metal-accummulation of Vetiveria zizanioides exposed to Cu, Zn, Pb and Cr-contaminated sediment were examined and the effect of chelator addition including EDDS, citric acid, EDTA and humic acid on phytoextraction of metals were also investigated in the hydroponic and pot experiments. In the hydroponic test, citric acid and humic acid enhanced the Cu, Zn, Pb and Cr levels in the roots of vetiver compared to EDDS and EDTA. EDTA induced the significant toxic effect owing to EDTA has complex ability leading less free metal ions. Despite of the toxic effect, the aerial plant parts translocation was viable compared to control. In pot experiment, the sequential extraction results showed that the mobility of Cu and Zn were higher than Pb and Cr. After adding EDDS and EDTA, it increased the loosely bound metals relative to control that indicated that sediment Cu, Zn, Pb and Cr mobility were enhanced. And the citric acid could enhance the mobility of Cr to improve the bioavailable of heavy metals. Phytoremediation efficiency factor (PEF) of vetiver were Zn ＞ Cu ＞ Pb ＞ Cr. After adding EDDS, the PEF of Cu, Pb and Cr increased 23, 7.5 and 2 folds relative to the control. For Cu, Zn, Pb and Cr, EDTA was by 31, 3.7, 19, 3 times, compared to the control PEF value. And the citric acid could increase 2 and 3.4 folds relative to the control of Cu and Cr PEF value. Adding humic aicd could not improve the phytoextraction of vetiver grass, but it could enhance the accumulation of Pb in roots.

並列關鍵字

vetiver grass (Vetiveria zizanioides) ； sediment ； phytoextraction ； chelator