Screening of Uranium Absorbing Organisms and U-Bioprocessing

铀吸收生物的筛选和铀生物加工

基本信息

批准号：
05041074
负责人：
SAKAGUCHI Takashi
金额：
$ 11.2万
依托单位：
Miyazaki Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

项目摘要

In recent years, the recovery of nuclear fuel elements such as uranium and thorium from aqueous systems using various microorganisms has become the center of hydrometallurgical process.We have been working on the bioaccumulation of nuclear fuel elements by various microorganisms and biosubstances from several angles.In a uranium deposit, it can be presumed that some micro-organisms having a high accumulating ability for uranium, and different species of microorganisms having an ability to leach uranium from ore may exist in mine soil and aqueous systems. It would, therefore, be useful to find further microorganisms having an enhanced ability to accumulate uranium from uranium deposits.To screen microorganisms isolated from uranium deposits and peculiar natural environments in North America and Japan for maximal accumulation of uranium, handreds of microorganisms were examined. Some microorganisms can accumulate about 600 mg (5 mEq) of uranium per gram of microbial cells within 1h. The uranium accumulating capacity of the cells is twice greater than that of commercially available chelating agents (2-3mEq/g adsorbent).We attempted to recover uranium form uranium refining waste water by using new microorganisms immobilized in polyacrylamide. As a result, these immobilized cells can recover trace amounts of uranium from uranium waste water with high efficiency. These strains have also a high accumulating ability for thorium. Thus, these new microorganisms isolated from uranium deposits and peculiar natural environments can be used as an adsorbing agent for the removal of nuclear elements that may be present in metallurgical effluents, mine tailings and other waste sources.

近年来，利用各种微生物从水体系中回收铀、钍等核燃料元件已成为湿法冶金工艺的中心。我们一直从多个角度研究各种微生物和生物物质对核燃料元件的生物富集作用。铀矿床中，可以推测一些微生物对铀具有较高的富集能力，并且不同种类的微生物具有从铀矿中浸出铀的能力。矿石可能存在于矿山土壤和水系统中。因此，进一步寻找具有从铀矿中积累铀的增强能力的微生物将是有用的。为了筛选从铀矿以及北美和日本的特殊自然环境中分离的微生物以最大程度地积累铀，对微生物进行了检查。有些微生物每克微生物细胞在1小时内可积累约600毫克（5毫当量）铀。该细胞的铀积累能力是市售螯合剂（2-3mEq/g吸附剂）的两倍。我们尝试通过使用固定在聚丙烯酰胺中的新型微生物从铀精炼废水中回收铀。结果，这些固定化细胞可以高效地从铀废水中回收微量铀。这些菌株还具有很高的钍积累能力。因此，这些从铀矿床和特殊自然环境中分离出来的新微生物可以用作吸附剂，用于去除冶金废水、尾矿和其他废物源中可能存在的核元素。