Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/52898
標題: 重金屬污染農地之偵測和整治復育策略與規範-藉瞭解重金屬與渠道及土壤固相之交互作用評估農地重金屬污染之整防治策略(III)
Evaluation of the Feasible Strategy for Remediating and Managing Heavy Metals-Polluted Farmlands (III)
作者: 鄒裕民
黃政恆
關鍵字: 環保工程;應用研究;heavy metal;重金屬;物種;復育;礦物;粒徑分布;speciation;remediation;mineral;particle size
摘要: 
台灣農地重金屬污染情形十分嚴重,這些重金屬主要來自灌溉渠道是一普遍被接受的事實,然而這些重金屬是由水體、懸浮膠體或底泥傳輸至農地?重金屬在農地的分佈是否與農民灌溉行為與模式有關?重金屬是否會因耕作土壤環境的改變而發生物種轉變與再分佈?一直是有爭議且未知的問題。本計劃將以重金屬與土壤礦物間的交互反應與物種鑑定為出發點,並配合環境因子(如pH, 氧化還原電位與離子強度等的變化)的變動,嘗試解釋整治後土壤再生產出含重金屬農作物之主因,並提出一可行的土壤整治與管理策略。本計劃第一年將以渠道底泥與懸浮顆粒與其所膠結的重金屬為主軸,觀察渠道與土壤不同粒徑無機礦物固相的種類,與其所攜帶重金屬的相關性。第二年則著重在重金屬在農地中的水平分布,一旦這些攜帶重金屬的固相粒子進入土壤後,其在土壤pH、離子強度與溫度等因子的影響下,是否有脫附的情形發生,導致重金屬在土壤中的再分布,造成生物有效性的提高,而此一過程是否是導致許多受污染的水稻田,在經過整治後仍有作物重金屬含量過高的主要成因,有待瞭解。此外,若重金屬穩定的附著在粒子上,不受土壤耕種或環境因子的改變而發生顯著再分布的情況,研究入水口至出水口不同粒徑中重金屬的含量與種類相對應的變化,亦即利用不同空間所篩選出相同粒徑下重金屬的含量變化來比較,應可說明固相對重金屬與土壤空間分佈的重要性。第三年的主要工作,將以帶重金屬不同粒徑的膠體為淋洗相,採管柱淋洗的方式瞭解含重金屬的膠體在土壤剖面垂直分布的情形;本年度工作也將探討不同乾濕交替環境條件下(導致氧化還原電位的改變),土壤中重金屬因環境改變所發生不同粒徑間金屬再分佈的可能,並以連續萃取技術,萃取土壤中不同型態之重金屬,觀察在氧化還原的變異下,那一種處理(持續乾燥、濕潤或乾濕交替處理),會形成生物可利用性較高之型態,並依結果提出可能的防治重金屬生物有效性增加的溫和處理策略。

Agricultural soils polluted by heavy metals have become a relatively serious problem in Taiwan. The depositions of heavy metals in soils is well-known a result of receiving polluted materials from irrigation ditches. However, due to the limited information regarding to the interactions of heavy metals with solid phases with various particles sizes, some controversies still exist, such as the major carriers (i.e., water, suspended colloids, or sediments) of heavy metals in irrigation ditches, the horizontal and vertical distributions of heavy metals in soils, the transformations of heavy metal speciation upon the changes in environmental conditions, and the possibilities of re-distributions of heavy metals in soils, etc. Therefore, the objectives of this project are to investigate the interactions of heavy metals with minerals and the characteristics of heavy metal species as influenced by environmental factors (i.e., pH, redox potential, and ionic strength). The aims of this project are to clarify the failure of the current remediation techniques and propose a new remediation and management strategy for heavy metal-polluted soils. First year, the correlations and associations of heavy metals with solids from irrigation ditch and soils with various particle sizes and mineral phases will be investigated. Second year, the possible desorption or dissolution of heavy metals from their interacted solid phases upon the changes in pH, redox potential, and ionic strength will be evaluated. This approach is to demonstrate the horizontal distributions of heavy metal in the farmlands and the changes in heavy metal species as influences by environmental factors or human activities. A heavy metal species, which is more susceptible to environmental changes or more abundant, will be selected as an indictor for this approach. Third year, a column experiment will be designed to investigate the vertical transportation of heavy metal in soil profiles. In addition, the changes in the speciation of heavy metals on various sizes of particles upon several dry/wet cycles will also be conducted. Our final goal is to propose a new remediation technique or management strategy to prevent any further heavy metal contaminations and/or to accelerate the removal of current pollutants.
URI: http://hdl.handle.net/11455/52898
其他識別: NSC99-2621-M005-001
Appears in Collections:土壤環境科學系

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