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年度	106	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	國立交通大學	申請系所	防災與水環境研究中心
專案主持人	林志平	職等/職稱	教授
專案中文名稱	土壤汙染現地寬頻電性量測技術研發
中文關鍵字	土壤汙染,介電頻譜,現地量測系統
專案英文名稱	Development of in-situ measurement system for broadband electrical properties of contaminated soils
英文關鍵字	contaminated soils, broadband electrical properties, in-situ measurement system
執行金額	700,000元
執行期間	2017/1/9 至 2017/11/30
計畫中文摘要	近年來環境地球物理探測在土壤污染的快速探測與評估中獲得越來越廣泛的應用，常見土壤污染物改變土壤孔隙水特性，甚而形成額外獨立相，即所謂的非水相液體（Non-Aqueous Phase Liquid）。因土壤電學特性改變而影響電流或電磁波在污染區域內傳輸產生異常，為地球物理探測的電學方法應用提供了探測前提。由於污染土壤為三相或四相的複和材料，其電學性質與土壤含水量、孔隙率、污染含量之關係相當複雜，有必要在相當寬的頻率範圍內來探討污染土壤的電學性質。本研究提出創新的時域反射技術多重反射訊號分析 (TDR RRA)方法，經室內試驗與現地試驗驗證可獲得10MHz – 1GHz寬頻的全電學性質（複介電度實部與虛部），對材料電學性質量測有很大突破。該量測系統具備容易組裝、標定及操作的特性，有助於探討各種污染物及不同土壤組成與含水量的電學特性，據以作為電學探測結果解讀與量化分析的依據。RRA在特定情況之量測可靠度較不佳，後續可加裝人工阻抗模組以產生一訊號穩定且無頻散現象之穩定R_1，並可延伸至與CPT貫入試驗結合，可應用於現地調查及監測。長期而言，現地污染探測需更完善寬頻電學量測技術，結合基於中高頻波傳方法與低頻電路方法，研發適合實驗室與現地試驗之試體感測器及現地貫入式探測器以達到此目標。
計畫英文摘要	Recent implementation of environmental geophysical exploration technique in rapid detection and evalution of soil contamination is widely involved. Typical soil contaminants tend to alter the pore fluid properties and some even form an individual phase, namely non-aqueous phase liquid (NAPL). Due to the variation of soil eletctrical properties, the transmission path of electrical currents or electromagnetic waves may be affected within the contaminated region, which in turn provided the detection basis of the electrical and electromagnetism methods in geophysical exploration methods. As contaminated soils consisted of composite materials of three or four phases, the relationship between their electrical properties and their water content, porosity, contaminant concentration are relatively complex. The demand for a wide electrical spectral range has hence arisen for contaminated soil detection. This study proposed an innovative Time-domain reflectometry (TDR) Remaining Reflection Analysis (RRA) method, in order to measure a broadband complex dielectric spectrum (including both real and imaginary parts of complex dielectric permittivty, CDP) within 10MHz – 1GHz frequency range and to perform a more complete electrical characterization of contaminated soil. The robustness, in-situ applicability, and performance of the proposed RRA method is verified using series of laboratorial and in-situ experiments, involving various contaminants. The measurement system of RRA can be setup, calibrated and operated easily, which assisted in investigating the electrical characteristics of various contaminants and soil composition. This provided useful insights into the interpretation of in-situ electrical exploration data results. However, RRA encountered some limitations in materials of highly dispersive or low dielectric permittivity. This limitation may be resolved by adding an impedance block prior to the sensing section and provide a steady, non-dispersive R_1. The TDR RRA sensing probe can even be adapted to CPT probe for field investigation and monitoring. In the long run, a more comprehensive broadband electrical measurement technique, which involves wave based and circuit based methods, is required for the ultimate goal of in-situ soil contamination exploration. Specimen probes and in-situ penetrating probes can also be designed and integrated with the aforementioned technique for laboratorial and in-situ experiments.