Refractory Organic Substances in Capillary Fringes: Dynamics, Gradients and Reactions

毛细管边缘是化学和生物化学转化的高度活跃区。由于合成有机微污染物的广泛存在，这些物质在非饱和区和饱和区的行为以及这些物质如何生物降解是一个具有高度生态意义的基本问题。污染物的可能转化及其代谢物整合到致微生物有机基质（结合残留物）中是基本的，但尚未得到很好的理解。可以预期，具有生物活性的边缘区对物质的降解和转化将非常活跃。本计画的主要目的是研究有机物在毛细管边缘的传质与生物转化。将量化相关过程和影响反应的主要参数。通过这种方式，将在2D罐（水平和垂直流），柱（垂直流）和批次（扩散）实验中进行研究。感兴趣的化合物（苯酚，水杨酸，苯磺酸，X射线造影剂和莠去津）的传质将被测量为水的水平流速，水位波动幅度和频率，可变渗透通量，水相的组成（高和低离子强度，NOM浓度）和边缘区的生物活性的函数。

The capillary fringe is a highly active zone for chemical and biochemical transformation. Due to the broad abundance of synthetic organic micro-pollutants it is a basic question with high ecological significance how these substances behave in the unsaturated and saturated zone, and how these substances are biodegradable. The possible transformation of the pollutants and the integration of their metabolites into the biogeogenic organic matrix (bound residues) is fundamental but not well understood. It can be expected that the fringe zone with its bioactivity will be highly active for degradation and transformation of substances. The main objective of this project is to study mass transfer and biological transformation of organic compounds across the capillary fringe. Relevant processes and the main parameters influencing the reactions will be quantified. By this, studies in a 2D-tank (horizontal and vertical flow), column (vertical flow) and batch (diffusion) experiments will be performed. Mass transfer of the compounds of interest (phenol, salicylic acid, benzene sulfonic acid, X-ray contrast media and atrazine) will be measured as a function of horizontal flow velocity of the water, water table fluctuation amplitude and frequency, variable infiltration flux, composition of the aqueous phase (high and low ionic strength, NOM concentration) and the bioactivity of the fringe zone.