Linking micro-aggregation to the sequestration of organic pollutants in soils

有机化合物的物理化学性质和空间位阻性质以及吸附剂的物理化学表面性质和结构性质决定了生物地球化学界面上的吸附相互作用。为了获得对这些相互作用的机理理解，我们想结合宏观、微量量热和光谱方法。我们假设极性有机化学物质在生物地球化学界面上的吸附和分布是由分子的疏水性r基（r决定）或其官能团（f决定）决定的。为了验证我们的假设，我们将研究双酚A和芬甲塞酮（由r决定的化学物质）以及苯达松和萘普生（由f决定的化学物质）在纯矿物系统（高岭石、伊立石、三水石和石英）、生物膜模型物质（聚半蜜醛酸和葡聚糖）、有机层矿物相组合系统以及表层土壤和底土中的吸附。对吸附等温线和吸附动力学进行解释和建模，这些吸附等温线和吸附动力学来源于批量实验，以及用可变交联的多糖进行扩散实验的结果，将为吸附相互作用提供宏观的见解。有关吸附热力学的信息将由微量量热法得到。光谱（ATR， FTIR， NMR）测量提供分子相互作用和结构的信息。

Physicochemical and steric properties of organic chemicals on the one hand and physicochemical surface properties and structural properties of the sorbent on the other hand determine sorptive interactions at biogeochemical interfaces. In order to gain a mechanistic understanding of these interactions we want to combine macroscopic, micro-calorimetric, and spectroscopic methods. We hypothesise that sorption and distribution of a polar organic chemical at biogeochemical interfaces is either determined by the molecules hydrophobic R-groups (R-determined) or its functional groups (F-determined). To test our hypothesis we will study sorption of bisphenol A and fenhexamid (R-determined chemicals), and bentazon and naproxen (F-determined chemicals) in pure systems of minerals (kaolinite, illite, gibbsite, and quartz), in model substances for biofilms (polygalacturonic acid and dextran), in combined systems of mineral phases with organic layers, and in topsoils and subsoils. Interpretation and modelling of sorption isotherms and sorption kinetics derived from batch experiments together with results from diffusion experiments with polysugars of variable crosslinking will provide macroscopic insight into sorptive interactions. Information regarding the thermodynamics of sorption will by derived from micro-calorimetry. Spectroscopic (ATR FTIR, NMR) measurements deliver information on molecular interactions and structure.