The role of mobile organic matter and biocolloids for the properties of and interactions with biogeochemical interfaces in soil

土壤作为物质输入的过滤器和转换器的功能是由生物地球化学界面（bgi）上的物理、化学和生物相互作用共同控制的。这些bgi在局部尺度上的性质对溶解物质和胶体物质（包括生物胶体）的相互作用具有决定性作用。局部尺度过程（例如（脱）吸附、孔扩散、微生物粘附、生物降解）似乎控制着连续尺度上的阻滞和转化的宏观现象。因此，本提案的目标是：(1)探索包括生物胶体在内的可移动有机物对bgi性质的作用，(2)量化不可移动空隙体积（PIVV）的比例，(3)揭示溶解和胶体化合物与bgi和PIVV在局部的相互作用速率和过程，以及(4)将其与连续尺度上的延迟和转化现象以机械方式联系起来。具有不同分子性质的有机和无机溶质将作为“过程示踪剂”来探测PIVV及其与bgi的相互作用和性质。最根本的挑战将是将不同尺度上获得的信息——通过光谱显微镜和计算化学获得的纳米尺度和分子信息，通过层析成像获得的聚合尺度信息和3d结构核心尺度信息——整合到一个有机化学品在土壤尺度上的流动、运输和转化的总体框架中。

Soil‘s function as filter and transformer of matter input is controlled by the interplay of physical, chemical and biological interactions at biogeochemical interfaces (BGIs). Properties of these BGIs at the local scale are decisive for interactions of dissolved and colloidal substances including biocolloids. Local scale processes (e.g. (de)sorption, pore-diffusion, adhesion of microorganisms, biodegradation) seem to govern the macroscopic phenomena of retardation and transformation at the continuum scale. The objectives of this proposal are thus to (I) explore the role of mobile organic matter including biocolloids for the properties of BGIs, to (II) quantify the proportion of the immobile void volume (PIVV), to (III) unravel the rates and processes of interactions of dissolved and colloidal compounds with BGIs and PIVV on the local, and to (IV) link it with the phenomena of retardation and transformation on the continuum scale in mechanistic ways. Organic and inorganic solutes with different molecular properties will serve as “process tracers” to probe PIVV as well as interactions with and properties of BGIs. The fundamental challenge will be to integrate the information obtained at different scales – nano-scale and molecular information by spectro-microscopy and computational chemistry, aggregate-scale information, and 3D-structural core scale information by tomography – into a general framework of flow, transport and transformation of organic chemicals on the pedon scale.