2013-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/680031摘要：在眾多持久性有機污染物中，溴化阻燃劑是行之有年、廣泛使用的一群含溴有機化合物，其中以多溴聯苯醚與六溴環十二烷之使用量占大宗，它們對生物之毒性以及逐年增加之環境累積量，將造成環境與人體健康之危害，因此如何有效去除環境中的污染物，是一項重要且急迫的工作。奈米金屬為新興的處理技術，高穩定性奈米金屬之材料與製程仍為全球產學界著重之研發要點；另外，基於成本與環境衝擊之考量，自然界中演化已久的微生物降解系統，亦極具開發與利用之優點，而生物降解之貢獻亦缺乏有效的監測方法。因此本計畫之目標為研發高穩定性及高效能之奈米金屬，篩選具降解能力之細菌，探討兩者在降解標的溴化阻燃劑之個別與加成效果，研究土壤環境中主要物理化學因子對上述處理方法之影響，另將創新以脫鹵酵素基因之表現量研發監測系統，供發展現地處理方法時做為參考。本計畫將利用不同聚合物進行製備高穩定性奈米零價鐵之試驗，或加以不同金屬為基材合成穩定性複合式奈米金屬，以及嘗試開發綠色化學製程以製備穩定性奈米金屬。首先測試奈米金屬的穩定性，在建立溴化阻燃劑最佳萃取分析方法後，探討奈米金屬處理溴化阻燃劑之反應動力學與反應活化能，並分析副產物，提出奈米金屬分解溴化阻燃劑的途徑。接著探討溫度、酸鹼度、陰陽離子、腐植酸、無機膠體等土壤物理化學因子，以及實際土壤溶液對奈米金屬反應活性之影響。同時自環境中篩選具有可降解溴化阻燃劑之微生物菌株或菌群，探討微生物降解溴化阻燃劑之動力與機制，並研究結合高穩定性奈米金屬與降解微生物對降解溴化阻燃劑之加成效果，藉由前述不同降解條件下之動力與機制分析，探討化學因子與生物因子之貢獻與影響。另外將結合分子生物學方法，針對降解微生物之脫鹵基因進行選殖，一方面利用脫鹵基因之表現建立微生物降解活性之監測方法，一方面探討脫鹵酵素之反應特性，以利於發展酵素式降解基材，另一方面更將篩選脫鹵相關作用因子，以了解細菌降解溴化阻燃劑之生物機制，擴大未來以酵素進行研發之目標。本研究預計完成穩定性奈米金屬之研發與環境微生物之篩選，兩類降解系統對溴化阻燃劑之降解效能研究，完成土壤物化條件對穩定性奈米金屬及微生物單獨或加成降解效能之探討，以及對基因表現、酵素活性及生物毒性之探討，這些結果將有助於發展以高效能與低成本之含鹵素持久性有機污染物處理技術。<br> Abstract: Among the various type of persistent organic pollutants (POPs), brominated flame retardants (BFRs) are widely used since a long time ago. Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were used mostly in the world. Due to their toxicity to human and the increased accumulation amount in the environment, developing methods to remove these compounds is an urgent and important issue. Nanoscale metals such as zero-valent iron or bimetallic complexes have been developed to degrade many POPs. However, better preparation methods for stabilized nanoscale metals are undergoing; also their effects on microorganisms are debated. Biodegradation system, which was developed along the evolution history, has huge potential and is waited for exploration. Therefore, we propose to develop BFRs degradation techniques from these two fields. The research objectives are: (1) establishing extraction and analyze methods for BFRs and their degradation by-products; (2) studying preparation methods for stable nanoscale zero-valent metals; utilizing environmental friendly solvents or reducing agents in the metal synthetic processes; (3) investigating the removal kinetics and mechanisms of BFRs by different nanoscale metals to develop most stable and efficient nanoscale metals; (4) elucidating the effects and contributions of physical or chemical factors from soil on the degradation efficiency, such as temperature, pH value, ions, inorganic and humic colloids; (5) screening microorganisms which have BFRs degradation ability; investigating the removal kinetics and mechanisms of BFRs by these microorganisms; (6) investigating the synergetic effect of nanoscale metals and microorganisms on BFRs degradation; elucidating the effects and contributions of physical or chemical factors from soil on the combined degradation efficiency; (7) understanding the biological mechanism in degradation through identification the enzyme associated proteins; (8) clone and express the degradation enzymes; measuring the degradation ability and substrate preference of enzymes in vitro; (9) valuing the gene expression of degradation enzymes through RNA and protein levels under different degradation conditions; (10) measuring the enzymatic activities under different degradation conditions. These understandings in nano-material science, chemical and kinetics analysis, microbiology and molecular biochemistry analysis would be helpful for offering new parameters to develop environmental techniques in POPs treatment.溴化阻燃劑多溴&#63895苯醚&#63953溴環十二烷&#63756米&#63754屬微生物&#64009解土壤brominated flame retardantpolybrominated diphenyl ethershexabromocyclododecanenanoscale metalmicrobial degradationsoil