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年度	109	專案性質	實驗性質
專案類別	研究專案	研究主題	自訂
申請機構	國立臺灣大學	申請系所	農業化學系
專案主持人	施養信	職等/職稱	教授
專案中文名稱	高濃度多溴二苯醚污染場址之土壤調查與整治測試
中文關鍵字	土壤,多溴二苯醚,持久性有機汙染物
專案英文名稱	Monitoring and remediation test investigation of polybrominated diphenyl ethers in highly contaminated site
英文關鍵字	Soil, polybrominated diphenyl ethers, persistent organic contaminants
執行金額	930,000元
執行期間	2020/1/30 至 2020/12/4
計畫中文摘要	多溴二苯醚 (polybrominated diphenylethers, PBDEs) 是一種溴化阻燃劑，常用於家用與工業產品中。然而斯德哥爾摩公約已將PBDEs列為持久性有機污染物 (persistent organic pollutants, POPs)，這些化合物不僅對環境有害，近年來更有許多文獻證實PBDEs對人體等具有危害性與致癌性。根據102年農委會委託本實驗室之計畫成果發現，在我國桃園地區部分農作物中檢測出PBDEs之污染，並在部分使用十溴二苯醚 (decabrominated diphenyl ether, DBDE) 之工廠附近土壤進行調查後檢測出PBDEs。根據本實驗室近年之農作物吸收污染物的試驗中發現PBDEs可能會藉由根部吸收方式傳輸至食用部位，PBDEs對土壤的污染將會透過植物吸收累積而對國人健康造成危害。先前對桃園地區高濃度PBDEs污染土壤的調查顯示該污染有向下移動之趨勢，且工廠周圍有國小、農田以及住家等，此污染將影響人民生活與食物安全。 本計畫延續去年結果持續監測桃園地區高污染場址中土壤PBDEs濃度變化，以及利用該污染場址之現地土壤開發可能之污染整治技術。目前已完成二批次 (2月及7月) 之高濃度PBDEs污染場址採樣，包含表土0公分、0-15公分、15-30公分以及30-60公分深度之土壤，共72件樣品之前處理與濃度分析。分析結果顯示，土壤中PBDEs污染仍以DBDE為主，表土與整體污染濃度與前幾年相比有下降情形，而污染濃度分布向深處土壤層移動的趨勢卻也更加明顯，甚至有些區塊30-60公分深處土壤之污染程度較其表土更高。在微生物方面，本團隊已自今年採樣土壤中篩選出四株菌，其中TY1表現最佳，經過一天便移除一半以上的DBDE，4天共移除約81%之DBDE。另外，單獨加入零價鐵時能較有效地移除DBDE，然而微生物 (TY1) 與零價鐵混合處理污染土壤時，反而產生抑制降解DBDE的現象。在溶劑清洗試驗中，結果發現甲醇具有較好的移除污染土壤中DBD之能力，唯該技術因清洗劑使用量大且廢液處理成本較高。最後藉由嘗試不同參數之熱處理移除污染土壤中之PBDEs，結果顯示300℃至450℃熱處理10分鐘以上均可使污染土壤中的DBDE移除率達到79%以上，其中以450℃加熱30分鐘之處理達到了91.3%的移除率，證實熱處理能有效去除土壤中DBDE。最後評估零價鐵結合微生物、溶劑清洗、熱處理等方法之整治效益後，以熱處理作為進行小區域污染土壤試驗之方法，已有良好去除效果，期望利用此農田的污染土壤開發可行之現地土壤整治技術，以促進該農田土壤之再生使用。透過本計畫，監測污染農田土壤中多溴二苯醚含量及分佈，同時開發可行之現地土壤污染移除試驗，以利未來污染農田之整治規劃，並提供規範PBDEs相關政策訂定之參考與建議。
計畫英文摘要	Polybrominated diphenylethers (PBDEs) are one kind of brominated flame retardants, which were usually added to many household and industrial products. However, some PBDEs were listed as persistent organic pollutants (POPs) in the Stockholm Convention. Besides, PBDEs not only polluted the environment but al-so were confirmed hazardous and even carcinogenic to the human beings by more and more research in recent years. According to the results of the year-102 Council of Agriculture project performed by our lab, it was found that some crops in Taoyuan area were contaminated with PBDEs. PBDEs were detected in the soil near the plant using decabrominated diphenyl ether (DBDE). Based on our recent studies regarding transportation of PBDEs by plant root to edible parts, they have shown the potential uptake route of PBDEs to edible parts of plants, which could threaten human health. Our previous investigations indicated one site with high concentrations of PBDEs and the pollution has a downward trend. Moreover, the contaminated plant is surrounded by school, farmland and houses, which will affect people's lives and food safety. In this project, the investigation is continued for the monitoring of PBDEs in the main contaminated farmland. Two batches (in February and July) of soil samples were all collected and analyzed. For the temporal and spatial surveys of the main contaminated farm, we analyzed depths 0 cm, 0-15 cm, 15-30 cm and 30-60 cm soils, totally 72 samples for their DBDE concentrations and found a decreasing trend from 2016 to this year, and still mainly DBDE contaminated. Furthermore, the depth distribution obviously showed that PBDEs have leached toward deeper soil. In some areas of the farmland, higher DBDE concentrations were even found in depth 15-30 cm and 30-60 cm than in depth 0 cm and 0-15 cm. In terms of microorganisms, we screened four microorganisms with PBDEs degradation potential from this highly contaminated soil. Among them, strain TY1 has a better removal efficiency of 81% of DBDE in four days with the rate constant of 0.269 day-1. In other aspect, although zero-valent iron (ZVI) can effectively remove DBDE. The degradation ability of PBDEs was slightly reduced when ZVI was combined with strain TY1 in contaminated soil. In the soil washing test, it was found that methanol has a better ability to remove DBDE in contaminated soil. However, this method needs a high processing cost. The lab-scale thermal treatments were carried out under the temperature between 300℃ to 450℃. The result shows that the removal efficiencies of DBDE in contaminated farmland soil can reach more than 79% after 10 to 30 minutes thermal treatment, and 91.3% removal efficiency was reached after 30 minutes under 450℃, indicating that thermal treatment is effective to remove DBDE. After evaluating some remediation methods including microbial degradation with zero-valent iron particles, soil washing technique and thermal treatment, we recommend that thermal treatment was the best technique to remove DBDE and has been applied in a small area test of this contaminated site. The good performance of PBDE removal was found in this test. Through this project, we monitored the content of PBDEs in contaminated farmland soils, developed feasible remediation methods for the future remediation of PBDEs in soils.