光透法定量粗糙裂隙生物堵塞下的隙宽

Models for quantification of aperture in a rough walled fracture bioclogging system with the light transmission method

基于光透法定量测量裂隙隙宽的原理及在两相流中的应用,设计了一组二维粗糙裂隙模拟装置研究微生物在裂隙地下水系统中的运移行为,首次定量研究了生物堵塞过程中隙宽及分布的变化。研究结果表明:微生物大多以离散菌簇状形态存在,未能形成明显的连续生物膜,不同空间位置微生物分布具有一定的随机性,本试验中微生物接种和营养注入方式决定了微生物集中分布在裂隙底部区域;微生物生长造成裂隙平均隙宽的下降(从1 181μm降低为1 086μm,下降8.04%),此外,基于光透法测量的不同空间位置隙宽(除2个点外)在微生物生长过程中都有所下降,两次微生物接种后点2处隙宽下降最明显(从1 275μm减少到1 081μm),下降了194μm,约为15.22%。光透法作为一种高效无损的室内监测手段,将其应用于裂隙介质的生物堵塞尤其是定量计算生物膜厚度的研究中,对裂隙中生物堵塞研究具有重要的参考意义。

Based on the light transmission method in quantification of aperture in a rough wall fracture bioclogging system and its application in a two-phase flow system, one group of 2-D rough wall fracture modeling device was developed to study the migration of microbes in a fracture groundwater system, and quantification of the variation in aperture and its distribution by bioelogging. The experiment results indicate that the most of the microbes exist in the form of clusters and do not form the obviously continuous biofilm. The microbes randomly occur in different spatial locations, however, they mainly appear in the bottom area of the fracture, which is controlled by the ways of microbes inoculation and nutrient injection. The average aperture of the fracture is reduced by bioclogging （from 1 181 μm to 1 086 μm with the percentage of 8.04）. Meanwhile, the apertures located at different points （except two individual points）, where apertures are calculated with the light transmission method, decrease during the process of microorganisms growth. Point 2 has the greatest reduction of 194 μm in aperture （from 1 275 μm to 1 081 μm） with the percentage of 15.22. The light transmission method is an effective and non-destructive monitoring method used in labs. It can be applied to the bioclogging, especially in the study of quantification of biofilm in fracture, which is of significant reference value in the related research work for bioclogging in fracture.