Soils are natural Particle-Fluid-Systems (PFS), in which complex physical, chemical and biological processes, interfacial processes, and phase transitions occur, that are not sufficiently investigated experimentally, well-understood, and that cannot be simulated numerically with sufficient accuracy yet. In technical PFS certain properties of particles are generated by means of controlled physical, chemical and biological processes, interfacial processes, and phase transitions (e. g. functionalized particles). Technical PFS also require further research regarding understanding, modelling and process optimization. The problems in natural and technical PFS are partly analogous. Therefore, it is obvious, to investigate processes in natural and technical PFS interdisciplinary in order to reach a benefit of scientific findings. Exactly in this point, the originary and the potential of the planned research training group can be seen. The individual disciplines name, model, and simulate similar processes identically or differently. Especially the length scales, on which PFS are investigated experimentally, modelled and simulated are different. By means of the cooperation with strategical partners and the facilities at TUHH, e. g. electron microscopy, the processes are visualized over several length scales. Process models and numerical simulation methods of the involved collegiates serve for better understanding and description of complex processes. By means of the cooperation and interdisciplinary methodology new findings are expected. A research training group provides an optimal framework to reach these objectives. Scientists of the disciplines civil engineering, mechanical engineering and process engineering will focus their research within the guiding topic ”Processes in natural and technical Particle-Fluid Systems“ (PintPFS). Existing competences and resources of the involved scientists regarding experimental investigations, modelling and simulation of PFS enable an interdisciplinary research approach that raises expectation of innovations in the following fields: progress in modelling of PFS, better understanding of capillary effects, modelling of erosion, transport and sedimentation processes, development of functionalized particles, as well as development of numerical experiments for PFS. The training group is supported by visiting scientists and strategical partners, especially by Deutsches Elektronen-Synchrotron (DESY) in Hamburg and Helmholtz-Zentrum Hereon. The proposed dissertation projects show the interdisciplinary research approach. To reach the objectives, the research training group is accompanied by structured qualification and supervision concepts for the PhD students supporting a fast orientation within the different research topics.