翁宜鴻 奈米物質水體環境風險篩選程序之研究
The Study of The Environmental Risk Screening Process of Nanomaterials in Waters 摘要 本研究的目的是利用物質本身的物理化學特性與水環境中會影響材料穩定性的 參數，建立奈米材料環境風險的篩選程序。本研究的基本假設為任何奈米物質進 入水環境後，仍然維持於奈米尺度(以 100 nm 為指標)，才需要去考慮其環境奈 米風險，否則應視為一般非奈米物質，可用現有之風險評估程序來評定其風險。 在本研究中主要分為二部分進行：(1) 利用物質物化特性(水溶解度、材料粒徑) 與水質參數 ( pH 值、離子種類、離子強度及天然有機物濃度) 配合三種人工合 成模擬水樣：河水、生活污水與海水，建立一套評估奈米風險的篩選程序；(2) 以奈米零價鐵、奈米鈀鐵複合金屬、奈米樹狀高分子及CdSe 量子點等奈米材料， 作為本篩選程序之測試材料，然後以人工合成模擬現實環境中之水樣(河水、生 活污水及海水)，進行材料穩定性實驗，穩定的奈米材料不易發生團聚作用，其 環境風險相對較不穩定者為高。將文獻回顧中有關奈米材料穩定度在水體環境中 之影響條件與以分類，根據水樣的水質對奈米材料穩定性影響程度的強弱，依序 排列為海水大於河水大於生活污水，並且本論文依不同穩定性，將奈米材料分為 四種類型分別為：不穩定性、弱穩定性、中穩定性與強穩定性奈米材料。而本研 究選擇之四種奈米材料經實驗後，將結果透過篩選機制之分析，判斷出奈米零價 鐵、奈米鈀鐵複合金屬與CdSe 量子點是屬於不穩定奈米材料，而奈米樹狀高分 子(Dendrimer)則屬於強穩定性奈米材料。因此，由本研究發現，奈米樹狀高分子 的環境風險遠較其他三者為高，應優先考量之。
The objective of this study was aimed at developing the screening process for the environmental risk of nanomaterials in waters based on the physical and chemical properties of substances and water quality parameters. The study was based on an assumption that the environmental risk of nanomaterials only takes place when they remain as nanosacle in waters. Thus, the factors that may alter the size of
nannomaterials in waters should be taken into a consideration. The physical and chemical properties of chemicals examined in the study are water solubility and particle size; the water quality parameters are pH, speciation of cations, ionic strength, and natural organic matter (NOM). Four types of nanomaterials were selected to test the stability in the study including Fe, Pd/Fe nanoparticles, dendrimer and CdSe quantum dot (QD). In this study, we used three kinds of synthesized waters to mimic riverwater, wastewater and seawater and developed a screening process to categorize the nanomaterials based on their stability in different waters. Nanomaterials can be classified as unstable, weakly stable, mid-stable and highly stable. According to the experiments, Fe, Pd/Fe and CdSe QD nanoparticles
were calssified as unstable whereas dendrimer was a highly stable nanomaterial. Therefore, the environmental risk of dendrimer should be a priority among others.
