海洋微生物对稀土元素矿化作用的实验模拟研究

Along with gradual reduction of rare earth mineral resources on land, the high enrichment of rare earth elements in ocean sediments has attracted a lot of attention. In addition to the abiotic factors of rare earth element enrichment, marine microorganisms also play an important role during the formation of mineral resourses in the modern ocean. However, the study of REEs enrichment and mineralization processes by marine microorganism is still in its preliminary stage in deep-sea environment. Relatively fewer studies have reported the biomineralization process of REEs in marine environment. In present study, the marine microorganisms separated from deep-sea sediments are used to investigate the interaction with REEs for experimental simulation research, and also the mechanism and kinetics during the long-term accumulation and mineralization process of REEs with microbes. A variety of advanced analytical techniques has been employed in the present study, including biogeochemistry, spectroscopy and geology methods. The objective of this study is to investigate the mineralization process and mechanism of REEs by marine microorganisms. Furthermore, this study will also provide the theoretical basis for further revealing the formation process of biogenic rare earth minerals and it’s influence factors in deep-sea geological environment.

目前在陆地上稀土矿产资源日渐减少之时，稀土在海洋沉积物中的高度富集受到广泛的关注。除了由非生物因素引起的稀土的富集成矿外，海洋微生物也对海底矿产资源的形成起着重要作用。然而，目前对海洋环境中微生物对稀土元素的富集和成矿作用等方面的研究还处于初步阶段，相关研究还不全面，其作用过程和作用机理还有待进一步的探讨。本课题以稀土元素和从海洋沉积物中分离的微生物为研究对象，进行由微生物引起的稀土元素成矿过程的实验室模拟研究。综合运用生物地球化学、光谱学、地质学等多种分析方法，重点研究稀土元素和海底沉积物中分离的微生物之间的相互作用。目标是阐明海洋微生物对稀土元素富集矿化的作用过程及其作用机理。为进一步探讨深海环境中的微生物成因的稀土矿物形成的过程及其影响因素提供理论依据。

近些年来随着人们意识到海底矿产资源的巨大潜能，对其逐渐产生了更大的兴趣。根据最新报道，在西北太平洋日本专属经济区域内发现了广泛密集分布的铁锰结核/结壳区域。他们认为该区域的铁锰结核/结壳含有经济价值的高潜力的金属材料，尤其是钴、镍、钼和稀土。多金属结核/结壳中深海矿物的形成不仅仅是地质作用而且由微生物驱动成因的过程（生物成矿）也非常重要。本项目中我们重点关注稀土元素的生物成矿过程，进行了微生物对稀土元素的实验室模拟过程研究。深海沉积物中筛选出三种不同的海洋细菌分别进行了对稀土元素Ce的富集吸附过程研究。此外我们还进一步比较了细菌和真菌对稀土元素Sm的成矿过程的不同。综合运用生物地球化学、光谱学、地质学等多种分析方法，考察了稀土元素富集的动力学过程；分析从稀土元素被微生物吸附富集到转化为矿物颗粒的过程，测定微生物作用过程中稀土元素形态的变化以及形成的稀土矿物的形态。通过实验室模拟研究，解析深海微生物对稀土元素的富集和矿化的作用过程，揭示深海沉积物和矿物中由微生物引起的稀土矿化的作用机理及其影响因素，探讨微生物在大洋稀土矿物形成过程中所起的作用。