Filtration is a phenomenon determined by multiple scales. They range from the flow regime around a moving vehicle to the atomic regime of adhesion forces between dust particles and an electrically charged filter medium. Fortunately, powerful computers, sophisticated models and new experimental equipment are available. Desktop computers with lots of memory and several fast CPUs, three-dimensional filter media models combined with REM and µCT images are some of the exciting developments that allow modeling and simulation work today that was unthinkable in the past. The talk will present examples how detailed three-dimensional filter media models, filter process models, CFD and statistics can provide valuable insights into filtration from both the practical and the academic point of view. It finishes with an outlook on how this work may also be applied in underground contaminant transport and someday even reactive flows.