以連續流矽膠管供氫管柱結合氫自營菌與零價鐵對水中三氯乙烯去除之研究

Abstract

含氯有機化合物如三氯乙烯，由於具有特殊之物化性質，所以廣泛地使用於工業中作為溶劑，其為具高潛在致癌性，會對人體肝臟和腎臟造成危害之合成有機化合物，若不慎滲漏至地表下，會造成土壤及地下水污染。 本研究主要以管柱試驗模擬現地含水層土壤受三氯乙烯污染之廠址，此技術包含安裝矽膠管以連續流供給氫氣作為電子供給者。實驗分別以氫自營菌、零價金屬鐵及兩者合併等三種實驗室尺度之管柱進行三氯乙烯之處理，結果顯示提供氫氣能增進生物之脫氯反應，將三氯乙烯完全脫氯為甲烷，且無含氯之中間產物生成。於零價鐵系統中，供給氫氣不但可增加還原脫氯反應速率、減少金屬離子之解離，亦可增加乙炔轉換成乙烯或乙烷之速率。本實驗之最終脫氯產物為甲烷、乙烷、乙烯及乙炔，均為脫氯之最終產物，這也顯示本合併處裡系統的確具有應用於現地復育的潛力。 由實驗結果可知氫氣自營菌-零價鐵合併處理的確具有加成效果，證實此合併處理技術可有效實際的應用在處理現地受三氯乙烯和氯化乙烯污染之廠址。

Chlorinated organic compounds, such as trichloroethene（TCE）, have been widely used as industrial solvents. They are completely synthetic organic compounds having carcinogen property and are known to cause damage to the human liver and kidney. Their releases into subsurface environments result in contamination of the soil and groundwater. Column experiments were performed to simulate a aquifers contaminated with TCE in situ. The technology involves installation of hollow fiber membranes to supply hydrogen gas （H2 ）as an electron donor. Three laboratory-scale columns were carried out by using combined zero-valent iron with autotrophic hydrogen-bacteria and compared with individual systems . The results show that hydrogen provided promote biological dechlorination in the individually biological and zero-valent iron combined with autotrophic hydrogen-bacteria system, TCE was dechlorinated to methane completely with no chlorinated intermediates were detected. In the zero-valent iron system, supplying of hydrogen gas increased dechlorination rate and suppressing the ionization of zero-valent iron and also can increase the rate of transform acetylene into ethene or ethane. Dechlorination rate of TCE by combined zero-valent iron with autotrophic hydrogen-bacteria was higher than individual systems. These findings suggest that the combined system is effective practical treatment of TCE and chlorinated ethylenes in contaminated sites.