地质微生物自然电场正演模拟与信号特征研究

Geomicrobes participate in a wide variety of redox processes of underground contaminants. Due to the sophistication of its bioelectrochemistry model, it is difficult to perform the forward simulation. The characteristics of microbial self-potential signal are still not unequivocal. It makes the signal recognition and extraction challenging. To solve these scientific problems, we plan to do some research on forward simulation and signal characteristics of self-potential induced by geomicrobes. 3D monitoring experiments of self-potential signals generated from cultivating typical bacteria in organic matter under laboratory controlled conditions will be performed to collect the time sequence signal samples of some typical microbial self-potentials. Based on the biogeobattery model, electric double layers, and electric dipoles, a macro geoelectric model of the geomicrobial self-potential will be constructed. Then, a natural element method will be developed to numerically simulate the complicated self-potential of geomicrobes. Blind source separation for monitoring self-potential signals based on non-negative matrix factorization will be used to extract the microbial self-potential signal. Then, the hidden Markov model and the particle filter are combined to estimate and recognize the characteristics of microbial self-potential signals. The project will contribute a lot to the environmental protection，the newly emerging biogeophysics, and promote the capability to understand the complex biogeological processes in the near surface environment.

地质微生物参与地下污染物氧化还原过程的生物电化学模型复杂，难以准确地正演模拟，产生的自然电场信号特征也尚不明确，难以识别和提取。项目针对这些科学问题，开展地质微生物自然电场正演模拟与信号特征的理论与方法研究。在实验室受控条件下对典型地质微生物生理过程中产生的自然电场进行三维监测，采集地质微生物自然电场时序信号样本。在生物-地电池模型的基础上结合电偶层和电偶极子，构建地质微生物自然电场的宏观地电模型。研究基于自然单元法的三维电场正演方法，实现地质微生物复杂自然电场的数值模拟。基于非负矩阵分解对监测自然电场信号进行盲源分离，提取地质微生物信号。然后融合隐马尔可夫模型与粒子滤波器对微生物电场信号进行特征估计与识别，获取典型地质微生物自然电场信号的时空特征。项目的实施对环境保护，对生物地球物理理论与方法的发展，对提升认知地球浅表环境中复杂生物地质过程的能力均有重要意义。

微生物在地球演化进程中作用重大，在不同时空尺度上与地球表层各圈层的改造和演变息息相关。地球物理方法具有非破坏性、实时监测、快速经济等显著优势，适合观测微生物、微生物活动以及它们与岩矿石之间的相互作用。地质微生物参与地下污染物氧化还原过程的生物电化学模型复杂，难以准确地正演模拟，产生的自然电场信号特征也尚不明确，难以识别和提取。项目针对这些科学问题，开展了地质微生物自然电场正演模拟与信号特征的理论与方法研究。在生物-地电池模型的基础上结合电偶层和电偶极子，构建了地质微生物自然电场的宏观地电模型。提出了基于自然单元以及自然单元-无限元耦合的三维数值计算方法，实现了地质微生物复杂自然电场的高精度数值模拟。在实验室受控条件下对典型地质微生物生理过程中产生的自然电场进行三维监测，采集了丰富的微生物自然电场时序信号样本。提出了基于非负矩阵分解的自然电场信号盲源分离方法，获取了典型地质微生物的电场信号特征。项目研究对环境保护，对生物地球物理理论与方法的发展，对提升认知地球浅表环境中复杂生物地质过程的能力均有重要意义。