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年度	110	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	多溴二苯醚高濃度污染場址土壤之整治初探
中文關鍵字	土壤、多溴二苯醚、持久性有機污染物、熱處理
專案英文名稱	Preliminary soil remediation test in highly contaminated site of polybrominated diphenyl ethers (PBDEs)
英文關鍵字	soil, polybrominated diphenyl ethers, persistent organic contaminants, thermal treatment
執行金額	990,000元
執行期間	2021/3/1 至 2022/2/28
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 (decabrominateddiphenylether, 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。本團隊過往已曾針對土壤中的有機污染物陸續開發出不同的整治 方法，包括熱處理、溶劑清洗法、微生物降解、光照降解、還原鐵降解以及植生復育等， 經評估這些方法之整治效益後，今年度計劃以熱處理作為污染土壤整治初探之方法，期望 利用此農田開發可行之現地污染土壤整治試驗，以利未來整治其它污染農田。根據最佳有 效處理條件為每分鐘升溫10 °C至450 °C 恆溫2小時，但不可避免土壤中的有機質從2.47 % 下降至0.27 %，直接影響土壤性質以及未來植物的生長。在分析污染土壤在不同熱處理條 件下之副產物的部分，增加土壤中的 DBDE 濃度後可看到有副產物的產生，證實加熱土壤 脫溴之作用。在土壤肥力回復實驗中，初步觀察到經由 450°C 處理2小時的土壤保水能力 較差，且透過市售的複合型肥料施肥不僅對植物生長沒有顯著的效果，反而有可能造成肥 燒傷。然而使用農業資材對肥力回復可以觀察到正面的效益，本研究中所使用的蔗渣肥， 在實驗當中加入2.5%的資材土壤中的有機質從百分比上升至2.73%，且植株生長狀況與受 污染土壤相近。因過高的溫度會導致土壤肥力的流失以及能源的消耗，透過調控熱處理的 溫度，將溫度調整至 250 °C恆溫2小時的條件下，土壤中的 DBDE 移除率可達到71.8 %以 上，殘餘濃度均減至 0.340mg/kg 以下，說明此溫度以及恆溫時間可以有效降低土壤中的 DBDE，並且對於土壤原本的性質改變相對較少，以達成綠色整治及環境永續的目標。
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). PBDEs not only polluted the environment but also were confirmed hazardous and even carcinogenic to the human beings 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 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. Previous investigations into the soil near the DBDE-utilizing plant in Taoyuan area have found PBDEs with concentrations up to 2 ppm 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. Our team has investigated different remediation methods for organic pollutants in the environment, including thermal treatment, solvent cleaning, microbial biodegradation, photodegradation, degradation by zerovalent iron particles, and phytoremediation. After evaluating the remediation benefits of these methods, this study focuses in thermal treatment as the method for remediation in the PBDEs contaminated site. The optimized conditions for DBDE removal at a step rate of 10 °C/min and hold for 2 hours at 450°C. Moreover, lower brominated byproducts were observed after the increase of DBDE concentration in soil samples, confirmed the debromination occurred during the thermal treatment process. However, the high temperature significantly decreased the original soil organic matter (SOM) of 2.47 % to 0.27 %, affecting the soil texture and the revegetation after the thermal treatment. Fertilizers were added in order to restore soil fertility. Pilot experiment have found that the water retention capacity of the soil was decreased after 450 °C treatment for 2 hours, and the direct application of compound fertilizers does not have significant effect on plant growth, and causes fertilizer burn. However, with addition of agricultural material leftovers such as addition of 2.5% bagasse, it could improve the SOM in soil up to 2.73% and make the plant growth conditions similar to those of contaminated soil without any treatment. To obtain balance between energy consumption and removal efficiency, the thermal treatment temperature was adjusted. Current results indicate that the removal efficiency can achieve up to 71.8% at a temperature of 250 °C for 2 hours. The residual concentrations of DBDE in the soil were lower than 0.340 mg/kg and the damage on the soil is relatively less than higher temperatures treatment, exhibiting an advance to achieve the goals of in green remediation and environmental sustainability.