| 水溶性有机物的电子穿梭功能研究 |
| 摘要点击 3565 全文点击 2285 投稿时间：2008-09-20 修订日期：2008-11-13 |
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| 中文关键词 水溶性有机物 中国希瓦氏菌D14T 氧化还原性 电子穿梭功能 |
| 英文关键词 dissolved organic matter(DOM) Shewanella cinica D14T redox reactive electron shuttling function |
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| 中文摘要 |
| 以源于污泥的DOM(dissolved organic matter)为供试材料，以中国希瓦氏菌(Shewanella cinica)D14T为电子转移驱动力，研究了DOM的氧化还原性能与电子穿梭功能.结果表明，污泥DOM可作为末端电子受体接受醌还原菌D14T呼吸链上的电子，从而转变为还原态DOM，而还原态DOM可将电子再次转移给Fe(Ⅲ).经D14T还原后，DOM电子供给量(e-/C)由初始2.2～14 μmol·g-1增加到253～347 μmol·g-1.循环伏安法与多次还原-氧化循环实验表明，DOM呈现2对明显的氧化还原峰，经3次还原-氧化循环后电子供给量可稳定维持在150～250 μmol·g-1之间，说明DOM具有重复利用、反复转移电子的特性.在菌株D14T还原水铁矿的体系中，加入DOM可提高水铁矿的还原溶解速率，其原因是DOM在D14T与水铁矿之间充当了电子穿梭体的角色.这些结果反映了DOM在电子转移反应中的重要性，为DOM的环境属性提出了一个新见解. |
| 英文摘要 |
| The redox reactive and electron shuttling function of dissolved organic matter (DOM) derived from sewage sludge were studied with Shewanella cinica D14T as driving force of electron transfer. The results indicated that sludge DOM initially served as terminal electron acceptor obtaining electrons from the respiratory chain of quinone-reducing bacteria D14T, then it translated to reduced DOM which can donate electrons to Fe(Ⅲ) again. The electron donating capacities (EDC) of DOM increased from initial capacity of 2.2-14 μmol·g-1 to 253-347 μmol·g-1 after DOM was reduced by D14T. The cyclic voltammetry measurements and multiple reduction-oxidation cycles experiments of DOM showed that two pairs of redox peaks were clearly observed and the EDC remained at a level of 150-250 μmol·g-1 after three reduction-oxidation cycles, indicating that DOM can be recyclably used for electron transfer. In the system of hydrous ferric oxide (HFO) reduction by S. cinica D14T, the reductive dissolution speed was improved with the presence of DOM, since that DOM was capable of acting as an electron shuttle between S. cinica D14T and HFO. These results demonstrate the important role of DOM in electron transfer process, and bring out a new perspective about the functions of DOM in the environment. |
