以生物刺激方式啟動含氯乙烯化合物厭氧生物脫氯反應探討

Evaluation of Anaerobic Reductive Dechlorination of Chlorinated Ethene by Biostimulation Technology

蔡婉楹(Wan-Ying Tsai) ； 林淑滿(Shu-Man Lin) ； 莊謹綸(Jin-Lun Chuang) ； 林志恩(Chih-En Lin)

《土壤及地下水污染整治》 2卷4期 (2015/10) Pp. 307-315

https://doi.org/10.6499/JSGR.2015.0204.005

摘要

重質非水相液體之地下水污染整治一直是國際間關注之重要環境課題，因其不溶於水且比水重的特性，造成的污染流佈相當複雜，使得工程師從調查階段、整治方法的選用及其整治成效的評估，均面臨極大的挑戰，近年來生物厭氧脫氯生物整治工法已成為重質非水相液體現地整治方式最為推崇的方案之一。本研究以台灣中部地區一處三氯乙烯地下水污染場址為標的，透過管柱測試，模擬現場地下水流速與生物製劑注藥條件等操作手段，除提供適量之生物碳源與營養鹽，並克服高地下水流速所造成高氧化還原電位問題，順利營造出厭氧還原環境條件；同時另搭配分子生物技術的驗證，發現系統中具有功能性微生物DHC、DCA1 的存在與TceA、BvcA 與VcrA 等三種酵素基因的表現，證實地下水中之三氯乙烯污染物可順利被代謝降解，整體去除率高達98% ( 進流濃度約1 mg/L)，可準確判定厭氧脫氯生物反應啟動之時間點與其代謝反應，有效提供現地生物整治操作方法評估。

關鍵字

重質非水相液體 ； 三氯乙烯 ； 厭氧脫氯反應 ； 生物刺激 ； 管柱試驗

並列摘要

The remediation of groundwater bearing dense non-aqueous phase liquids (DNAPLs) is an environmental issue of great concern. The physical and chemical properties of DNAPLs, such as relatively low solubility and high specific gravity, make the accurate identification of their distributions difficult. This makes it very challenging to carry out comprehensive investigations of these substances, to choose appropriate remediation technologies, and evaluate the remediation performance at contaminated sites. In situ bioremediation is an emerging technology that creates an anaerobic environment to enhance reductive dechlorination in groundwater and promote the sequential biotransformation of TCE to DCE, VC and ethene. The focal site in this paper is a trichloroethylene (TCE) contaminated aquifer located in central Taiwan. This study evaluates biostimulation using column tests to simulate the groundwater flow and injection criteria of the biologics in the targeted site. During the test, the anaerobic system was successfully developed by providing both a carbon source and nutrients. The results of a molecular biotechnology analysis confirmed the existence of functional microbes DHC and DCA1 in the TCE biodegradation system, and the expression of three enzyme genes (TceA, BvcA and VcrA). The TCE removal efficiency reached up to 98% (with an initial concentration of 1 mg/L). The results help confirm the startup criteria for anaerobic dechlorination and the metabolism for in situ bioremediation.

並列關鍵字

dense non-aqueous phase liquid ； TCE ； reductive dechlorination ； biostimulation ； column test