Hydration affected soil:water sorption processes of xenobiotics - experiments and modeling approaches

SOM不是被动吸附剂，但可以被山梨酸盐物理改变。这已经在水分子和阳离子中得到了证明。本文假设有机外源物的吸附参与了SOM的形成，并引起SOM物理结构和理化性质的变化。这些变化反馈到吸附过程中。吸附和（竞争性）二次吸附已被证明是敏感的措施，使过程的机械（热力学）建模。为此，选择了10种具有一系列物理化学性质和对SOM预期影响的溶质，并将其与具有不同SOM数量和组成的三种土壤样品和聚半乳糖醛酸钙网络（Ca-PGA）相结合作为SOM模型。在不同的条件下（阳离子交联、温度、溶剂性质、有机-矿物结合、老化时间）进行批量试验，获得吸附程度、非线性、滞后、动力学和竞争的数据。相应地，利用DRIFT、DSC、1H-NMR和表面表征方法，对吸附诱导变化前后的SOM进行了全面表征，并确定了SOM-山梨酸结合机制。数据将结合并使用机械多位点和多相模型和分子力学计算模型建模。

SOM is not a passive sorbent but may be physically altered by the sorbate. This was already shown for water molecules and cations. Here it is hypothesized that sorption of organic xenobiotics takes part in the formation of SOM and induces changes in SOM physical structure and physicochemical properties. These changes feed back on sorption processes. Sorption and the (competitive) sorption of secondary sorbates have been shown to be sensitive measures enabling mechanistic (thermodynamic) modeling of processes. For that purpose, ten solutes offering a range of physicochemical properties and expected effects on SOM were selected and will be combined with three soil samples with different SOM quantity and composition and a polygalacturonic calcium network (Ca-PGA) as model SOM. Tested in batch trials and under varied conditions (cation crosslinking, temperature, solvent properties, organo-mineral association, aging time) data on sorption extent, nonlinearity, hysteresis, kinetics and competitiveness will be obtained. Correspondingly, SOM are thoroughly characterized before and after sorption induced changes and SOM-sorbate binding mechanisms are identified, using DRIFT, DSC, 1H-NMR, and methods for surface characterization. Data will be combined and modeled using mechanistic multisite and multiphase models and molecular mechanics computational modeling.