以同步輻射X光吸收光譜法探討受重金屬污染農地土壤之物種分布及轉變(3／3)
| 中文摘要 | 本計畫以同步輻射X光吸收光譜配合序列萃取法，發展重金屬污染土壤之鋅物種型態分析方法，以探討污染農地土壤鋅物種空間分布和轉變傳輸機制，以及耕犁工法是否可能導致鋅物種型態轉變或擴散所產生的風險。自桃園和彰化各一塊選取重金屬污染場址，於耕犁工法整治前後採集不同距離和深度之土壤樣品進行分析。結果顯示土壤中鋅的主要物種主要以與黏土礦物鍵結或類似鍵結構造之物種為主。序列萃取法的金屬型態則顯示高移動性和生物有效性之物種型態於入水口處最高，隨離入水口之距離和深度而減少，因此越接近入水口，人為污染的貢獻越高。經過整治的土壤，土壤的鋅濃度，以及不同距離和深度之鋅物種型態分布趨於相近，表土鋅之不安定性下降，顯示耕犁工法的成效。三年之計畫成果顯示鉻、銅和鋅之物種分布在耕犁工法前後有類似的趨勢，但依鉻、鋅、銅的順序呈現不穩定性增加之趨勢。在方法學上以X光吸收光譜分析少數關鍵樣品的物種組成資訊，配合序列萃取法分析大量樣品來獲得定量分析之資訊，兩者互補為探討污染場址土壤中重金屬物種型態轉變之最完整方法。 | ||
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| 中文關鍵字 | 重金屬、X光吸收光譜法、序列萃取法、生物有效性、金屬物種分布 | ||
基本資訊
| 專案計畫編號 | NERA034112016 | 經費年度 | 112 | 計畫經費 | 3500 千元 |
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| 專案開始日期 | 2023/01/01 | 專案結束日期 | 2023/12/31 | 專案主持人 | 王尚禮 |
| 主辦單位 | 國環院環境治理研究中心 | 承辦人 | 柯雅婷 | 執行單位 | 國立臺灣大學 |
成果下載
| 類型 | 檔名 | 檔案大小 | 說明 |
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| 期末報告 | 成果報告.pdf | 7MB | 成果報告 |
Development of X-ray absorption spectroscopic method for the study of chemical speciation and transformation of heavy metals in contaminated soils (3/3)
| 英文摘要 | This project aimed to develop the X-ray absorption spectroscopic (XAS) method to determine the chemical speciation of zinc (Zn) in contaminated farmland soils before and after the soils were remediated using the tillage method. The information was further used to evaluate the potential Zn risk in the soils after the remediation. Soil samples were collected from different locations in two contaminated farmlands in Taoyuan and Changhua before and after remediation. The XAS results of the soils showed that the predominant Zn species in the soils are Zinc-adsorbed on clays (illite). The chemical speciation and fractionation, obtained using sequential extraction methods, showed the contents of residual phase were relatively constant over the contaminated sites, while those of the other species and phases with higher mobility and availability increased with decreasing the distance from the irrigation water inlets of the farmlands or soil depth. The highest contents of mobile species in the soils near the irrigation water inlets revealed the input of Zn from anthropogenic sources through irrigation water. After remediation, the total content and the chemical speciation/fractionation in the soils at different locations became similar, and the solubility of Zn in the surface soils decreased. These results indicated the positive effects of the tillage remediation method on decreasing the bioavailability and associated risk of soil Zn contamination. In summary of the results of the three-year project, the spatial distribution of Cr, Cu and Zn species exhibited similar trends before and after the tillage remediation method, while their labilities followed the order of Cu > Zn > Cu. The complementary information from combining the XAS and sequential extraction method allows the effective identification of the predominant phases of heavy metals in soils and understanding their chemical transformation under certain conditions in the environment. | ||
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| 英文關鍵字 | Heavy metals, X-ray absorption spectroscopy, Sequential extraction, bioavailability, Chemical speciation | ||