不同螯合劑對促進蕹菜吸收污染土壤中鎘、鉛效率的比較

Efficiency of different chelators on enhancing the absorption of cadmium and lead by Lpomoea aquatic in a soil

王國珍(Kuo-Chen Wang)

指導教授 ： 許正一

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2015年)

https://doi.org/10.6346/NPUST.2015.00136

摘要

新興的土壤復育技術如植生萃取(Phytoextraction)，可使重金屬累積於植物，自土壤去除有毒金屬，是一種對環境友善和低成本的修復技術，可於土壤中添加螯合劑或化學試劑來增加植生萃取的成效。本研究於受鎘及鉛污染的砂質壤土中種植蕹菜(Lpomoea aquatic)，利用蕹菜吸收重金屬，污染土壤的鎘、鉛濃度分別為未添加重金屬Cd、2.5、5.0、7.5、10及15 mg Cd/kg及未添加重金屬Pb、250、500、750、1,000及1500 mg Pb/kg，評估施用EDTA(Ethylenediaminetetraacetic acid)、EDDS(Ethylenediaminedisuccinic acid)及低分子量有機酸(檸檬酸、琥珀酸、草酸及醋酸)對於促進植生萃取的效果。實驗結果顯示，在未添加重金屬之土壤中草酸處理較其他處理來的適合促進蕹菜累積鎘濃度，高濃度污染土壤則以EDTA較適合，累積鉛濃度以EDTA較為適合。不同螯合劑對蕹菜植生萃取鎘皆於未添加重金屬時植生萃取效率較高，高污染濃度時效率最低，TF(Transfer factor)則於低污染土壤時轉移係數最佳。鉛污染土壤僅EDTA、檸檬酸、琥珀酸及草酸於低污染土壤時植生萃取效率較高，而對照組、EDDS及醋酸則於高污染土壤時較高，TF則於EDTA及檸檬酸處理組時效果最佳。

關鍵字

植生萃取 ； 蕹菜 ； 鎘 ； 鉛 ； 螯合劑 ； 低分子量有機酸 ； 轉移係數

並列摘要

Emerging technologies such as phytoextraction, heavy metals can be hyperaccumulated in the plant for removing these metals from contaminated soils, is an environmentally friendly and cost-effective technique for soil remediation. Chelating agents can be added to the soil for increasing the bioavailability of heavy metals in the soil. Water spinach (Lpomoea aquatic) was planted in the study soil contaminated by cadmium and lead ranging in 2.5, 5.0, 7.5, 10, and 15 mg Cd/kg and 250, 500, 750, 1000, and 1500 mg Pb/kg, respectively EDTA(Ethylenediaminetetraacetic acid), EDDS(Ethylenediaminedisuccinic acid), and low molecular weight organic acids (citric acid, butanedioic acid, oxalic acid, and acetic acid) were spiked into the soil to enhance the uptake of Cd and Pb in the plant. The experiment results show that heavy metals in the soil without adding Cd and Pb had higher metal uptake in oxalic acid treatment in comparison with the other treatment. In highly contaminated soil, EDTA revealed the best enhancing ability of accumulating metals for the plants. The phytoextraction efficiency of the plant in low contaminated soil was higher than that in highly contaminated soil. Additionally, TF (Transfer factor) was higher in low contaminated soil. Regarding Pb, the TF value was higher in the treatments of EDTA and citric acid.

並列關鍵字

Phytoextraction ； Lpomoea aquatic ； cadmium ； lead ； Chelator ； low molecular weight organic acid ； TF

參考文獻

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