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年度	103	專案性質	實驗性質
專案類別	研究專案	研究主題	底泥
申請機構	弘光科技大學	申請系所	環境與安全衛生工程系
專案主持人	胡慶祥	職等/職稱	助理教授
專案中文名稱	底泥有機污染物生物有效性評估及應用
中文關鍵字	底泥；有機污染物；生物有效性；生態風險；政策法規
專案英文名稱	Assessment and Application of Bioavailability of Organic Contaminants in Sediments
英文關鍵字
執行金額
執行期間	2013/11/25 至 2014/11/24
計畫中文摘要	本研究專案採用固相微萃取技術(solid phase microextraction, SPME)預測有機污染物在不同真實底泥特性下的生物有效性，針對底泥常見污染物多環芳香烴(PAHs)，擇1～4 環芳香烴為目標，探討不同來源底泥、底泥現地化學整治前後、混合2 種PAHs 以及不同污染齡(aging period)對生物有效性的影響，建立適用於底泥污染物生物有效性的量化評估方法，獲得底泥PAH 的真實暴露參數(亦即荷蘭RIVM生物有效濃度代表實際暴露濃度)，提出具體科學性數據，以落實土污法中關於風險評估的立法意旨及達成底泥管理的政策目標。 研究結果發現，隨著污染齡的增加生物有效性會大幅減少，而且生物有效性在污染齡四個月之內減少的趨勢最為顯著，此結果說明了有機污染物於底泥中有明顯的貯滯作用(sequestration)，此作用降低了污染物的有效性，進而相對降低了暴露風險。在底泥有否先經現地化學整治(採persulfate 化學氧化法)對於生物有效性評估值與實際微生物降解量之相關性方面，其整體評估結果R2 為0.97，推斷SPME 技術應用於實場時，並不會因底泥中有機質含量不同與是否先經過化學氧化處理而影響其預測準確性。至於底泥中存在2 種PAHs 時，SPME 技術對於整體有效量稍有低估，因為SPME 無法評估出微生物在雙重污染下會產生促進降解的現象，但是SPME 能準確預測單一污染的生物有效性，不受有機質含量、污染物共存與否的影響，顯示SPME 技術在特定條件下具有良好的應用性。綜合前述，SPME 技術可應用於底泥PAH 的生物有效性評估，其生物有效量(即SPME 萃取量)可取代底泥污染物全量，作為風險評估過程中的實際暴露量，以計算合理風險值。此外，本研究以PAH 生物有效量試算場址污染影響潛勢評估總分(TOL)值，結果TOL介於611～989間，均低於以全量計算所得(達1200 分以上)，顯示納入生物有效性考量將實質改變底泥管理策略。
計畫英文摘要	This research was to investigate the variations of bioavailability of polycyclic aromatic hydrocarbons (PAHs) in different sediment origins, before and after in-situ chemical remediation, PAH mixture, and aging periods. Solid phase microextraction (SPME) was employed to estimate the bioavailability of PAHs in sediments. One to four-rings PAHs in sediments were selected as the target pollutants. It is expected that optimal bioavailability measurement for the sediment pollutants could be established, through which actual exposure concentrations of PAHs in sediments can be obtained. Based on the emerging policy and legal framework in the Netherlands, i.e., representing actual exposure by bioavailable fraction, and specific scientific data and information derived from this project, suggestions regarding implementation of risk assessment in sediment management could be proposed to Taiwan EPA. Experimental results indicated that the PAH bioavailability largely decreased as aging periods increased, especially for that aged 4 months. This result illustrated that PAH sequestration occurred significantly in sediments. The sequestration reduces bioavailability and in turn decreases exposure risk. With respect to the effects of chemical oxidation (using persulfate oxidation) on the assessment of PAH bioavailability, very good relationships were found in between the extracted amount and the biodegraded, with the correlation coefficient R2 as high as 0.97. Under the presence of a PAH mixture, SPME slightly underestimated the bioavailable fraction due to the occurrence of synergistic degradation. However, SPME accurately estimated the bioavailability of a single PAH regardless of the organic contents. In conclusion, SPME can be implemented to the assessment of PAH bioavailability in sediments. The bioavailable amount (SPME-extracted), representing the actual exposure, should replace the total amount in risk assessment. Further, our calculation of TOL based on the bioavailable fraction of PAH indicated that the values (611-989) were below those calculated on the basis of the total amount (over 1200). The strategy on sediment management could be totally amended when taking bioavailability intoconsideration.