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Academic investigation of hot spring's microbial mats included high concentration of heavy metals (Au,Ag,Hg,Sr).

学术调查显示温泉微生物垫含有高浓度的重金属（金、银、汞、锶）。

基本信息

批准号：
14405001
负责人：
TAZAKI Kazue
金额：
$ 9.28万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

In 2002 and 2003,field researches were carried out to investigate biomats in geothermal area and in hot springs in Kamchatka, Russia. We have observed bacteria in all cases which precipitate a significant amount of various heavy metals. In 2004,filed studies were achieved focusing biomats in Hokuto Hot Springs, Taiwan, and Tamagawa Hot Springs, Japan. The both hot springs are famous of precipitation of hokutolite, radioactive barite. In this study we observed γ-ray radioactivity of ^<226>Ra (42.2 Bq/g) and ^<228>Ra (1.35 Bq/g), and this indicate that ^<226>Ra of uranium series is predominant. In 2005,a collaborative research with the group of Prof.Muhongo, Dar Es Salaam University, Tanzania, was carried out targeting a mercury-pollution caused by the small-scale gold mining around Geita, on the south coast of Lake Victoria, Tanzania. Samples of water, sediments, soil, biomats and aerial dusts were collected around ten small-scale mining sites, and many observations were made such as mineral identification, analyses of chemical compositions, etc. Optical microscopy and electron microscopy elucidated mercury distribution concentrated around the cell of microorganisms and clay mineral particles. All these field researches and laboratory works on biomats found in geothermal area, hot springs and metal mines elucidated atmosphere-water-soil-microorganisms interactions and biomineralization. An important role of microorganisms and mechanisms in formation of heavy metal minerals were clarified in nanometer-scale using electron microscopes. These results are fundamental data valuable for application of bioremediation in heavy metal-polluted area.

2002年和2003年，在俄罗斯堪察加半岛的地热区和温泉中进行了生物垫的实地调查。我们在所有情况下都观察到细菌沉淀大量的各种重金属。2004年，在台湾的北户温泉和日本的玉川温泉进行了集中生物垫的实地研究。这两个温泉都以沉淀北石、放射性重晶石而闻名。在本研究中，我们观测到了^<226>Ra（42.2Bq/g）和^<228>Ra（1.35Bq/g）的γ放射性，这表明<226>铀系的^ Ra占优势。2005年，与坦桑尼亚达累斯萨拉姆大学Muhongo教授小组合作开展了一项研究，针对坦桑尼亚维多利亚湖南岸盖塔周围小规模金矿开采造成的汞污染。在10个小型矿区周围采集了水样、沉积物、土壤、生物垫和空气粉尘样品，进行了矿物鉴定、化学成分分析等观测，光学显微镜和电子显微镜观察表明汞在微生物细胞和粘土矿物颗粒周围富集分布。通过对地热区、温泉和金属矿中生物垫的野外研究和室内实验，阐明了大气-水-土壤-微生物相互作用和生物矿化作用。利用电子显微镜在纳米尺度上阐明了微生物在重金属矿物形成中的重要作用和机制。研究结果为生物修复技术在重金属污染区的应用提供了基础数据。