Investigation of pore scale processes at biogeochemical interfaces using sensor micromodels and Raman microscopy

土壤中的生物地球化学界面（BGI）控制着有机化学物质的命运和土壤作为保护地下水资源的过滤器的功能。为了理解和量化华大基因的过程，必须测量有机化学物质的浓度梯度，并监测华大基因自身的时空动态。具有土壤孔隙结构的微流体系统（微模型），允许在不同环境条件下以单界面分辨率可视化华大基因在流动系统中的空间发展。本项目扩展了微模型技术，采用化学敏感传感器层和拉曼显微镜，以高时空分辨率（<2 μm, <1 s）测量十六烷和菲的浓度、可能的降解产物和华大基因的变化。测量是非破坏性的，并且不需要在流体流动中使用示踪剂。华大基因空间特征和浓度梯度的时间序列数据是华大基因过程量化的基石，为分子水平（AFM）、孔尺度可视化（CLSM、μCT）和微米尺度项目之间的联系提供了桥梁。

Biogeochemical interfaces (BGI) in soil control the fate of organic chemicals and the functioning of soil as a filter to protect groundwater resources. To understand and quantify the processes at BGI, the concentration gradients of organic chemicals have to be measured and the spatial and temporal dynamics of the BGI themselves have to be monitored. Microfluidic systems with the pore structure of soils (micromodels), allow the visualize the spatial development of BGI in a flow through system under varying environmental conditions with single interface resolution. This project extends the micromodel technique with a chemically sensitive sensor layer and with Raman microscopy to measure the concentration of hexadecane and phenanthrene, possible degradation products and changes of the BGI with high spatial and temporal resolution (<2 μm, <1 s). The measurements are non-destructive and do not require tracers in the fluid flow. The time series data of the spatial features and concentration gradients at BGI is a keystone for quantification of the processes at BGI and provides a link between projects on the molecular level (AFM), pore scale visualizations (CLSM, μCT) and projects on the dm-scale.