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年度	112	專案性質	實驗性質
專案類別	研究專案	研究主題	調查
申請機構	國立臺灣大學	申請系所	環境工程學研究所
專案主持人	林逸彬	職等/職稱	教授
專案中文名稱	建立台灣本土土壤中塑膠微粒定性定量方法之研究
中文關鍵字	土壤, 塑膠微粒, 定性, 定量
專案英文名稱	Development of qualitative and quantitative methods for microplastic analysis of soil in Taiwan
英文關鍵字	Soil, microplastic, qualitative and quantitative methods
執行金額	1,067,987元
執行期間	2023/12/15 至 2024/11/29
計畫中文摘要	塑膠微粒係指粒徑小於5 mm以下之塑膠碎片，其已在大多數環境水體中被檢測到，近年來，在土壤或底泥中也被發現有塑膠微粒的存在。塑膠微粒可能會吸附有機污染物並累積在土壤中，影響有機污染物在地下水中的傳輸。有關環境中塑膠微粒之檢測方法，在水相中主要以傅立葉轉換紅外線光譜儀與拉曼光譜儀之定性定量方法為主，以及使用染劑配合螢光、立體顯微鏡之定量方法。在土壤與底泥中，需先以氧化劑去除有機質以防止其在分析過程對光譜與染劑的干擾，並結合水相的偵測方法，評估土壤中塑膠微粒之定性定量分析技術之可行性，以驗證整體分離技術操作方法對各式塑膠的有效性。 本研究首先以富含鋁、鐵等金屬成分之紅土及砂質土為土壤樣品，研究發現過氧化氫為目前去除土壤有機質干擾之較佳試劑，且所測試之PP、PVC、HDPE、PET及PA66等大顆粒塑膠(2-3 mm)未受到試劑破壞。接續以更小粒徑的PP、PVC及PE塑膠 (20~600 µm)摻入土壤作為試樣，並以高密度之氯化鈣及氯化鋅鹽類溶液進行塑膠分選，研究結果顯示在兩種土壤中以氯化鈣為分選液，並經兩次分選下有較佳之分選回收成效。粒徑約600 µm之PE採肉眼辨識，回收率達九成；更小粒徑之PP、PVC採螢光顯微鏡進行染色計數確認回收率，PP之回收率以104 %為最佳，PVC之回收率最高僅56%。調查實際農田土壤之塑膠微粒，平均每克之土壤約含有600顆塑膠粒，且至少存在有PP及PE塑膠。本研究目前之方法仍有回收率不足之問題尚待克服，因此後續建議增加分選次數及分選液密度，以提升塑膠顆粒之回收率。
計畫英文摘要	Plastic debris with a size smaller than 5 mm are termed “microplastics”. Micro-plastics have been detected in natural waters, soils, and sludges. Microplastics could be harmful due to their physical and chemical properties. Regarding the detection of microplastics in the environment, fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy are mainly used for qualitative and quantitative analysis, and fluorescence microscopy and stereomicroscopy are also applied recently. This study aims to develop a method for the detection of microplastics in soil samples. Sandy soil and laterite soil were chosen as soil matrix in this study. Hydrogen peroxide was found to be the most effective reagent to digest soil organic matter, and polypropylene (PP), polyvinyl chloride (PVC), high density polyethylene (HDPE), polyethylene terephthalate (PET) and polyamide 66 (PA66) plastic were not damaged by the reagent. Smaller sizes of PP, PVC and PE microplastics were then spiked in the sandy and laterite soil, and high-density solutions including calcium chloride (CaCl2) and zinc chloride (ZnCl2) were used to extract microplastics from the digest-ing solution. The results showed that CaCl2 was the better separation solution, and two cycles of separation could achieve better recovery efficiencies. PE with a size around 600 m was visually identified, with an average recovery of 90 %. PP and PVC with size ranging 20-80 µm and 20-300 µm, respectively, were counted using dye-assisted fluorescent microscopy. The optimal recovery of PP was 104 %, while that of PVC was only 56 %. The qualitative and quantitative detection of microplastic for actual farmland soil was conducted. There were approximately 600 microplastics per gram of soil, and PP and PE plastics were both found using µ-FTIR analysis. Since the current method still has limitations in the recovery, it is recommended to increase the separation cycles and use a separation solution with a higher density in the future to improve the recovery.