應用地電阻影像剖面法於DNAPLs污染場址調查之研究

本研究應用地電阻影像剖面法(Electrical Resistivity Tomography，ERT)於某工業區之土壤與地下水進行調查，該研究區域廠家多數為電子產品加工、製造為主，生產過程皆需大量使用含氯有機溶劑，含氯之有機溶劑多屬於比水重之非水相性溶劑(Dense Non-Aqueous Phase Liquids，DNAPLs)且為可能致癌物質，故判定地層中的DNAPLs有其必要性。本文研究目的在於調查地層環境的分佈與疑似污染造成之異常區的延續關係，並配合地下水採樣分析結果，進而研判污染物質的分佈與流向，作為釐清污染問題責任之佐證。潛勢工廠上下游與場區周界，結果顯示除舊有6口監測井為已知污染處外，經ERT探測後更發現其他15處地下水可能含有二氯乙烯或三氯乙烯。後續之鑽井及下水取樣得已證實。其中三氯乙烯最高濃度更超過地下水管制標準7倍，二氯乙烯超標達3倍，證明ERT可有效應用於調查受DNAPLs污染之大型工業區。

關鍵字

地電阻影樣剖面法；比水重非水相液體；含氯有機溶劑

並列摘要

This study reports the results of using Electrical Resistivity Tomography method to investigate the groundwater and soil in an industrial estate. Chlorinated solvent is one of the raw materials being widely used in the manufacture process of the electronic products for most of the factories located in this industrial estate.Chlorinated solvent is well known to be a Dense Non-Aqueous Phase Liquids (DNAPLs) and may be carcinogenic. So, it is necessary to detect DNAPLs plume in this study area.The purpose of this study is to investigate the situation of contaminated subsurface and to provide the anomalous zones having DNAPLs contamination; simultaneously, combining the ERT results with the groundwater samplings, the distribution and flow direction of pollutants can be recognized. Thus the possible contaminated marker can be pointed out. Fifteen ERT survey lines were conducted around the study site. In addition to 6 previous monitoring contaminated wells, fifteen possible contaminated locations were pointed out and verified by later water samples obtained by well drilling. The highest concentration of trichlorethylene and dichloroethylene in the groundwater sample was over seven times and three times of the maximum levels respectfully. The result indicated that the ERT method could be an effective way to detect the DNAPLs contamination at this site.