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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	整治
申請機構	國立台灣大學	申請系所	環境工程學研究所
專案主持人	于昌平	職等/職稱	副教授
專案中文名稱	以植物微生物燃料電池技術復育受六價鉻污染土地的研究
中文關鍵字	植生復育, 生物電化學系統, 植物微生物燃料電池, 鉻
專案英文名稱	Plant Microbial Fuel Cell Technique for Remediation of Cr(VI) Contaminated Site
英文關鍵字	Phytoremediation, Bioelectrochemical system, Plant Microbial Fuel Cell, Chromium
執行金額	600,000元
執行期間	2017/1/9 至 2017/11/30
計畫中文摘要	研究成果中文摘要 土壤重金屬污染是一個全球性的污染問題，其中六價鉻（Cr(VI)）為一種廣泛存在的重金屬污染物，在台灣的一些土壤污染列管場址就含有Cr(VI)，其毒性及遷移性都遠大於三價鉻（Cr(III)）。Cr(VI) 污染的大量存在會對人體健康和生態安全產生潛在的危害，並且是一種致癌物。 微生物燃料電池為一新興的環境生物技術，由微生物和電極系統組成，最近開發出耦合植物及微生物電化學技術的植物微生物燃料電池系統，利用植物根系分泌物，提供根系的微生物包含產電菌作為碳源，促進微生物胞外電子傳遞，結合電極系統，可以收集能源。 本研究計畫之目的在於評估以植物微生物燃料電池技術復育Cr(VI)污染土壤，提升對Cr(VI)的去除效果，同時並能產能。目前研究進度，先構建基於蘆葦及狼尾草等植物微生物燃料電池系統，並利用蘆葦與狼尾草對不同濃度的Cr(VI)污染土壤，分別是0 mg/kg, 50 mg/kg, 200 mg/kg 與500 mg/kg的樣品在溫室進行實驗。透過不同濃度的試驗，以求得最佳處理參數。之後進行機理的探討，植物吸收及微生物電化學系統對Cr(VI) 在電極上的還原及沉積的協同作用，達到促進Cr(VI)在土壤中的去除效果及產能。這些參數將有助於我們進行受污染實場的試驗。 由實驗的結果顯示，實驗的土樣經過植物微生物燃料電池的運行，由酸性土壤提升至中性土。土壤導電度也下降超過100 μs/cm。土壤六價鉻最大平均的去除率超過99%。土壤總鉻也是隨著系統的運行逐漸下降。運行過程中，使用石墨碳氈為電極的實驗組在外接1KΩ電阻下可在當日平均產生產生平均469.21 mV的輸出電壓。應用在實際污染土壤，53天後，系統可去除67.07%的土壤六價鉻，以及產生64.70mV的輸出電壓。 經由實驗結果，可確定植物微生物燃料電池進行去除Cr(VI)的機制以電化學過程為主。此外，Cr(VI)在系統中的還原作用可沉澱在電極上。去鉻微生物與植物的吸附作用也會有去除Cr(VI) 與總鉻的反應。從直接與間接效應來衡量，不管是處理污染物、無二次污染、綠化、使用太陽能、產生綠色能源與生態保育等觀點，植物微生物燃料電池進行土壤復育具有多功能的作用。
計畫英文摘要	Abstract Heavy metals contaminated soil is a global pollution problem. Cr(VI) is a widely reported heavy metal contaminant and it has much higher toxicity and mobility than Cr(III). Some reguratory sites in Taiwan contain Cr(VI). Widespread Cr(VI) contamination will pose a serious threat to the health of human and ecosystem. It is also a carcinogen. The microbial fuel cells (MFC) is an emerging environmental biotechnology. It is composed of microorganisms and electrodes system. When microorganisms metabolize organic pollutants, extracellular electron transfer (EET) to the electrode will occur, and therefore, can simultaneously achieve pollutant treatment and electricity collection. In this proposal, we intend to evaluate the use of PMFC for bioremediation of Cr(VI)-contaminated soil and also produce energy at the same time. We will build a PMFC based on Phragmites australis and Pennisetum alopecuroides under different Cr(VI) concentrations samples, 0 mg/kg, 50 mg/kg, 200 mg/kg and 500 mg/kg in the green house. By different concentrations in research, we will evaluate the best treating performance. Furthermore, we will explore mechanisms of PMFC: We will use Phragmites australis’s and Pennisetum alopecuroides’s ability to uptake Cr(VI) and also use MFC system to reduce Cr(VI) to Cr(III) and precipitate Cr(III) on the electrode. We hope the integrated mechanisms can enhance Cr(VI) removal in contaminated soil and produce energy. The research in this proposal can improve the current knowledge of treatment techniques in Cr(VI) removal, providing useful information in actual Cr(VI) contaminated sites. According to this experiment, PMFC makes acid soil to neutral soil. In addition, PMFC could decrease electric conductivity of soil more than 100 μs/cm. Third, the maximum removal of Cr(VI) in soil is 99%. Moreover, total Cr also is decreased with time. After 53 days, maximum average output voltage of PMFC systems with graphite carbon felt could achieve 469.21 mV. According to actual contaminated soil experiment, PMFC could remove 67.07% Cr(VI) in contaminated soil and produce 64.70mV output voltage. From the results, the major mechanism of Cr(VI) removals is the bioelectrochemical process. In addition, redox reactions in PMFC promote Cr(VI) precipitate on the electrode. Furthermore, Cr-reducing microorganisms and plant uptake improve Cr(VI) and total Cr removals. Finally, from the direct and indirect benefits, PMFC for soil remediation possess multiple functions: treating pollutants, no secondary pollution, greening, utilizing sunlight energy, generating green energy, and ecological conservation, etc.