Characterization and control of behavior of microbial community in subsurface soil environment during the in situ bioremediation

原位生物修复技术作为一种有效的土壤修复技术已引起人们的广泛关注。对于原位生物修复，了解和控制微生物群落的分布、迁移和活动是至关重要的。然而，微生物群落在地下土壤中的行为尚未得到很好的记录。因此，本研究旨在1)研究地表以下几米的地下土壤微生物群落结构，2)利用石油烃污染的现场渗滤仪监测自然衰减过程中微生物群落结构的变化，3)研究微生物细胞在多孔介质中的运输。本研究为原位生物修复提供了有益的信息。1)地下土壤微生物群落结构利用呼吸醌谱分析了黄壤旱地剖面、河沙剖面和海滨剖面的微生物群落结构。随着深度的增加，微生物的生物量和多样性呈下降趋势。然而，在地下土壤中存在高碳含量的高生物量和多样性点。不同土壤剖面的地下土壤群落结构相似。2)石油烃自然衰减过程中微生物群落结构的变化。在非饱和条件下，对某油田渗滤仪进行石油烃污染，利用呼吸醌谱监测污染土壤1年以上微生物群落结构的变化。石油烃在渗渗仪中通过入渗水向下输送。当石油烃浓度最大达到3000 mg/kg时，特定醌种类增加，表明降解微生物繁殖。石油烃耗散后，群落结构恢复到污染前的状态。以朔那河土壤为微生物源，玻璃微珠为多孔介质，研究了水对微生物细胞的渗透运输。当入渗水量较大时，土壤颗粒的输运量与输运的微生物细胞呈正相关关系，而在低流量情况下则不存在正相关关系。在高流速和低流速下，游离菌和附着菌的比例存在差异。少

In situ bioremediation has attracted attention as a useful technology for clean up the contaminated soil. For in situ bioremediation, it is essential to understand and control distribution, transportation, and activities of microbial community. However, the behavior of microbial community in subsurface soil has not been well documented. Thus, this study aimed 1)to examine the microbial community structure in subsurface soil several meters below the ground surface, 2)to monitor the changes in microbial community structure during the natural attenuation using a field lysimeter contaminated with petroleum hydrocarbons, and 3)to examine the transport of microbial cells through porous media. This study will provide useful information to the in situ bioremediation1)Microbial community structure in subsurface soilStructures of microbial community were examined for upland yellow soil profile, river sand profile, and seashore profile using respiratory quinone profile. The microbial biomass and … More diversity decreased as the increase in depth. However, there are spots with a high biomass and diversity in subsurface soil where carbon content was high. The community structures in subsurface soil were similar among the soil profiles.2)Changes in microbial community structure during natural attenuation of petroleum hydrocarbonsA field lysimeter under an unsaturated condition was contaminated with petroleum hydrocarbons, and changes in the structure of microbial community in the contaminated soil was monitored using respiratory quinone profiles over 1 year. Petroleum hydrocarbons transported downward in lysimeter by infiltration water. Specific quinone species increased when petroleum hydrocarbon concentration increased to 3000 mg/kg at maximum, indicating propagation of the degrading microorganisms. After petroleum hydrocarbons dissipated, community structure returned to the one before the contamination.3)Microbial transport through porous mediaTransport of microbial cells by infiltration water was examined using a Sho-na-i river soil as a microbial source and glass beads as porous media. A high flow rate of infiltration water resulted in the transport of soil particles, which showed a positive correlation with microbial cells transported, but not in the case of low flow rate. There were differences among the proportions of free and attached bacterial cells between the high and low flow rates of infiltration water. Less