成果專區 - 土壤及地下水污染整治基金補助研究與模場專案宣導網

專案基本資料

年度	109	專案性質	實驗性質
專案類別	模場試驗	研究主題	調查
申請機構	國立中興大學	申請系所	環境工程系
專案主持人	梁振儒	職等/職稱	特聘教授
專案中文名稱	含氯污染物高解析被動式採樣器開發測試及現地應用評估
中文關鍵字	高解析場址調查, 被動式採樣, 氯化有機污染物, 揮發性有機物監測
專案英文名稱	Development of high resolution passive sampler for tracking chlorinated organically contamination and evaluation of field application
英文關鍵字	High Resolution Site Characterization, passive sampling, chlorinated organic contaminants, VOCs monitoring
執行金額	1,510,000元
執行期間	2019/11/1 至 2020/10/31
計畫中文摘要	國內列管的土壤及地下水污染場址中，受碳氫化合物污染之場址數量最多高達 86.4 %，其中以含氯脂肪族碳氫化合物為最多占56.4 %。透過高解析場址調查建立場址概念模型可有助於定位污染物洩漏位置，作為整治技術可行性評估之依據。地表下氣相及水相污染物採樣技術，可分為主動式採樣(Active sampling, AS)與被動式採樣(Passive sampling, PS)，其中被動式採樣具備操作方法簡易且不干擾污染物狀況等優點，通常可更真實反應地表下之污染分布狀況。鑑於國內發展高解析場址調查對土壤及地下水整治之重要性，本計畫擬開發可同時適用於未飽和含水層氣體污染物及飽和含水層地下水液相污染物之高解析被動式採樣器，並進行現地應用驗證，提升被動式採樣技術之應用層面，並藉由高密度之被動式採樣佈點，有效掌握實場DNAPL污染源及地下水污染團之分佈。本計畫第一年利用聚二甲基矽氧烷(Polydimethylsiloxane, PDMS)半透膜透析(Dialysis) 機制設計開發及製造高解析被動式採樣器，探討被動式採樣器對於水相及氣相TCE與採樣器之平衡時間及適用範圍，分析結果得知水相TCE 3 mg/L~25 mg/L與採樣器所需之平衡時間需>10天，進一步平衡反應時間14天進行試驗得知，此採樣器可應用之水相TCE濃度範圍為0.05~150 mg/L。此外，氣相TCE濃度介於2.6~26 mg/L之間，平衡反應時間需>12天，因此綜括水相及氣相實驗，建議此被動式採樣器可採14天作為取樣所需之平衡時間。砂箱模擬試驗中，主動式採樣因受幫浦抽氣影響，容易產生干擾而產生錯誤之TCE濃度分布，而被動式採樣相較於主動式採樣，有較準確之場址概念模型，應驗被動式採樣可彌補主動式採樣之短處。模場試驗以慶川及東陽場址進行現地應用評估，對於低濃度之採樣結果，可知被動式採樣器可測得之物質濃度較被動式採樣袋及微洗井採樣方法靈敏，可測得其他兩種方法無法測得之微量污染濃度；對於高濃度場址之採樣結果可知，三種採樣方法所得之數據比低濃度污染採樣相關性較高，受VOC逸散之影響程度較低。對於未飽和層之氣體採樣，傳統手持式PID之採樣所得之數據變異甚大，被動式採樣器之數據較為穩定；證實本研究之被動式採樣器能夠追蹤評估TCE於未飽和含水層之污染位置範圍，更容易精準判斷TCE污染源位置。第二年則將於具較高及較低三氯乙烯地下水污染之二處污染整治場址進行大規模實場驗證。
計畫英文摘要	Among Taiwan EPA regulated contaminated soil and groundwater sites, organic hydrocarbons contaminated sites account for 86.4%, in which chlorinated aliphatic hydrocarbons account for 56.4%. High-resolution site investigation is possibly allowed for precisely tracking positions and distributions of contamination, thereby as a basis for identifying the restricted contamination area and designing a remediation project. Gaseous and aqueous phase samplings can be classified as active sampling and passive sampling methods. The passive sampling owns advantages of simple operation and no disturbing to contamination and may reflect true contamination distribution. Based on the demand for developing high-resolution site investigation for soil and groundwater remediation, the proposal intended to manufacture a high-resolution passive sampler, which could be applied in both unsaturated and saturated aquifer for detecting gaseous and aqueous phase contamination. Also, a field demonstration was conducted to ensure the applicability and identification of DNAPL via high densities of passive samplings. The first year’s objectives of this two-year project were to design and manufacture a passive sampler based on polydimethylsiloxane membrane dialysis mechanism, and examination of equilibrium sampling time and contaminant concentration range in gaseous and aqueous phases. The results indicated that an equilibrium time period of >10 d was required in the aqueous phase containing TCE concentrations ranging from 3 to 25 mg/L, while an equilibrium time period of >12 d was necessary for TCE vapor concentrations ranging from 2.6–26 mg/L. Therefore, a 14 d of equilibrium time was suggested for application of this passive sampler in detecting vapor and aqueous phase TCE. The multilayer passive sampling was conducted in a three-dimensional sandbox to construct a tomography of TCE vapor spatial distribution in the vadose zone above the saturated water level. After collection of the passive samples from the three-dimensional sandbox, a three-dimensional visualization was created, and it was demonstrated to be a reasonable way to simulate a three-dimensional TCE distribution. A pilot field testing for the passive sampler was conducted in two sites, including Chingchuan and Dongyang. In the relatively low contamination site, the passive sampler could detect trace concentration level in groundwater and is more sensitive than other sampling methods (low flow sampling and passive diffusion bag). In the high concentration site, the results obtained through three sampling methods revealed similar concentration values with high correlation. For detecting contamination in the unsaturated zone, the concentration detected by the portable PID showed significant deviations, while the passive sampler provided stable concentration values. It was confirmed that the passive sampler developed in this study is effective for assessing TCE contamination in the subsurface. The second year’s objects will be conducted in these two sites with full investigation for ensuring the applicability of the passive sampler.

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