| 摘要: | 四氯乙烯（perchloroethene, PCE）、三氯乙烯（trichloroethene, TCE）、1,1,2-三氯乙烷（1,1,2-trichloroethane, 1,1,2-TCA）含氯有機物因其特性為比水重之非水相液體(dense non-aqueous phase liquid, DNAPL)，進入地下環境後，因其低黏滯性使其可在地表下快速移動，低表面張力使其容易穿入土壤小孔隙或岩石裂隙，造成整治困難度高。生物整治法被喻為自然、環保及節能的處理技術，也是目前環境污染整治的趨勢。現地生物復育技術可行性其中最重要條件之一為場址本身須具有可降解污染物之微生物。當場址中可降解污染物微生物數量較低或場址整治急迫性高時，可額外添加微生物進行生物強化(Bioaugmentation)整治受污染之場址。雖然許多微生物已證明可降解TCE至中間產物 Vinyl chloride (VC)，但VC具有更高毒性和累積性，因此如何去除環境中 VC 汙染，是生物復育一項重要課題。在厭氧環境，已被證實一種脫氯菌 (Dehalococcoides)可以完全還原 VC 至乙烯，但脫氯作用需要氫氣作為電子提供者，降解初期氫氣含量仍充足，因此脫氯作用速率較為快速，但至降解後期氫氣逐漸消耗殆盡使脫率速率降低，因此本研究第一年度欲自現地地下水中篩選出產氫菌株，並利用固定化技術比較數種固定化材料，以增加產氫菌株穩定度、產氫活性與毒物耐受性，並利用次世代定序菌相分析技術分析整治前後菌相變化，評估添加固定化產氫菌株與營養基質是否對脫氯菌株有益，以增進含氯有機物整治效益。第二年度本研究將以台南永康模場作為實場整治試驗地點，建立與評估添加產氫菌與營養基質對於地下水含氯有機污染物污染場址之整治效益，做為未來整治TCE污染更具經濟效益及環境友善之綠色整治工法。 ;Chlorinated organic compounds such as perchloroethene (PCE), trichloroethene (TCE) and 1,1,2-trichloroethane (1,1,2-TCA) which characteristic is dense non-aqueous phase liquid (DNAPL). When entering the underground environment, it can move rapidly under the surface due to its low viscosity, and its low surface tension makes it easy to penetrate the soil Small pores or rock cracks, causing remediation difficult. Bioremediation has been hailed as a natural, eco-friendly and energy-saving treatment technology, and also the current trend of environmental pollution remediation. One of the most important conditions for on-site bioremediation technology is that the site itself must have microbes that can degrade contaminants. When the number of the degradable microbes at the site is low or the remediation site is of high urgency, additional microorganisms may be added for bioaugmentation to remediate contaminated sites. Although many microorganisms have been shown to degrade TCE to the intermediate product Vinyl chloride (VC), VC is more toxic and cumulative, so how to remove VC contamination in the environment is an important issue in biological breeding. In anaerobic environment, Dehalococcoides have been shown to completely reduce VC to ethylene, but dechlorination requires hydrogen as the electron donor. Hydrogen content is still sufficient during the initial period of dechlorination, so the rate of dechlorination is faster but up to hydrogen was gradually depleted in the late stage of degradation to decrease the rate of de-rate. Therefore, in the first year of this study, hydrogen-producing strains were screened from the groundwater in situ and several immobilized materials were compared by immobilization technology to increase the stability of hydrogen-producing strains, hydrogen activity and toxics tolerance. The next-generation sequencing phase analysis technique was used to analyze the change of bacteria phase before and after remediation. It was evaluated whether the addition of immobilized hydrogen-producing strains and nutrient matrix could be beneficial to dechlorination strains to improve the remediation benefit of chlorine-containing organics. The second year of this study will be Tainan Yongkang mode field as a real-site remediation test sites to establish and evaluate the addition of hydrogen-producing bacteria and nutrient matrix for contaminated sites contaminated by groundwater contaminated sites of the remediation benefits as a future TCE pollution control more economic efficiency and environmental friendliness of the green renovation method. |
