Application of Carbon Materials to Biological Treatment of Mine Drainag

从北海道南部温泉附近的锰矿床中分离到一种氧化锰真菌，经形态学、生理学和遗传学鉴定为Phoma sp.。真菌在中性pH下氧化Mn（II）离子，最适pH为6.8。随着介质中有机碳源的减少，Mn（II）的氧化速率增加。真菌的Mn（II）氧化需要蛋白胨和酵母提取物作为碳源，葡萄糖的加入延缓了氧化速率。真菌氧化的最大Mn（II）限值为120ppm，在实际矿井水Mn浓度范围内。PAN型碳纤维明显增强了真菌Mn（II）的氧化速率，提高了溶液的透明度。具有相同直径和长度的PET纤维的工作原理却不同。这可能与碳纤维的生物亲和性有关。通过x射线衍射（XRD）鉴定了生物源型锰氧化物为γ-MnO_2 （ramsdellite）。SEM观察发现，生物源mn -氧化物具有孔径，平均直径为4nm，且在碳纤维存在时孔径分布更为明显。碳纤维可以稳定真菌诱导的晶体生长。多孔γ-MnO_2除用于二次矿水处理外，还具有应用于电池材料的可能性。

A Mn-oxidizing fungus has been isolated from Mn-deposits around the hot spring in the southern part of Hokkaido, and identified to be Phoma sp.based on morphology, physiology, and genetics. The fungus oxidizes Mn(II) ions at neutral pHs and the optimum pH was 6.8. With decrease in organic carbon sources in the mediaum, Mn(II) oxidation rate was increased. The fungal Mn(II) oxidation required peptone and yeast extract as carbon sources, and the rate were delayed by the addition of glucose. Maximum Mn(II) limit for the fungal oxidation was 120ppm, which is in the range of Mn concentrations in actual mine drainage. The PAN type of carbon fiber has clearly enhanced the fungal Mn(II) oxidation rate, and improved the transparency of the solution. The PET fiber, which has the same diameter and length, did not work similarly. This might be caused by bio-affinity of carbon fiber.The biogenic Mn-oxides were identified to be γ-MnO_2 (ramsdellite) by XRD. According to SEM observation, the biogenic Mn-oxides were porous with 4nm in an average diameter, and the pore sizes were more sharply distributed in the presence of carbon fiber. Carbon fiber might stabilize the crystal growth induced by the fungus. The porous γ-MnO_2 has the possibility for application to battery materials in addition to the second mine drainage treatment.