Physicochemical Aging Mechanisms in Soil Organic Matter (SOM- AGING): II. Hydration-dehydration mechanisms at Biogeochemical Interfaces

土壤有机质的物理化学老化机制（SOM-AGING）：II。生物地球化学界面的水合-脱水机制

• 批准号: 40935425
• 负责人: Professorin Dr. Gabriele Schaumann
• 金额: --
• 依托单位: Universitätsleitung - Präsidium
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/40935425?language=en
• 关键词: Physicochemical; Aging; Mechanisms; Soil; Organic

Soil organic matter (SOM) controls large part of the processes occurring at biogeochemical interfaces in soil and may contribute to sequestration of organic chemicals. Our central hypothesis is that sequestration of organic chemicals is driven by physicochemical SOM matrix aging. The underlying processes are the formation and disruption of intermolecular bridges of water molecules (WAMB) and of multivalent cations (CAB) between individual SOM segments or between SOM and minerals in close interaction with hydration and dehydration mechanisms. Understanding the role of these mediated interactions will shed new light on the processes controlling functioning and dynamics of biogeochemical interfaces (BGI). We will assess mobility of SOM structural elements and sorbed organic chemicals via advanced solid state NMR techniques and desorption kinetics and combine these with 1H-NMR-Relaxometry and advanced methods of thermal analysis including DSC, TGADSC- MS and AFM-nanothermal analysis. Via controlled heating/cooling cycles, moistening/drying cycles and targeted modification of SOM, reconstruction of our model hypotheses by computational chemistry (collaboration Gerzabek) and participation at two larger joint experiments within the SPP, we will establish the relation between SOM sequestration potential, SOM structural characteristics, hydration-dehydration mechanisms, biological activity and biogechemical functioning. This will link processes operative on the molecular scale to phenomena on higher scales.

土壤有机质（SOM）控制着大部分发生在土壤生态化学界面的过程，并可能有助于有机化学物质的固定。我们的中心假设是，封存的有机化学物质是由物理化学SOM矩阵老化。潜在的过程是水分子（WAMB）和多价阳离子（CAB）的分子间桥梁的形成和破坏的各个SOM片段之间或SOM和矿物之间的密切相互作用与水合和脱水机制。了解这些介导的相互作用的作用将揭示新的光的过程控制功能和动态的地球化学界面（BGI）。我们将通过先进的固态NMR技术和解吸动力学评估SOM结构元素和吸附的有机化学品的流动性，并将这些与1H-NMR-弛豫法和先进的热分析方法（包括DSC，TGADSC-MS和AFM-纳米分析）结合联合收割机。通过控制加热/冷却循环，润湿/干燥循环和有针对性的修改SOM，重建我们的模型假设通过计算化学（合作Gerzabek）和参与两个更大的联合实验SPP内，我们将建立SOM封存潜力，SOM结构特征，水合-脱水机制，生物活性和生物化学功能之间的关系。这将把分子尺度上的过程与更高尺度上的现象联系起来。