Innovative filter module to separate microplastics from wastewater - SimConDrill

Microplastics are small plastic particles with a diameter of < 5 mm [1], which are either deliberately used in various products or are the result of natural abrasion and erosion. Synthetic microplastic particles, which are called primary microplastics, serve in many hygiene products as peeling particles, enter the water cycle after use of the product [2, 3]. Secondary microplastics are plastic parts that are created from larger plastic components through degradation processes or wear and tear. These include, for example, tire abrasion on the roads or textile fibers from functional clothing [4]. All types of microplastic particles, whether primary or secondary, which get into our wastewater and are fed into the wastewater treatment plant are not sufficiently filterable. According to a study by the Alfred Wegener Institute, more than 700 particles/m³ and thus up to 5.3 billion particles/year [5, 6] were not retained in the filtered wastewater of a typical wastewater treatment plant. The development of new innovative water filters that counteract this problem is therefore inevitable.
The Federal Ministry of Education and Research BMBF is currently funding the project "Innovative filter modules for the separation of microplastics from wastewater", in short "SimConDrill". The aim of the project is the development of an innovative filter module for the removal of microplastics in wastewater from wastewater treatment plants. In order to realize this goal, the technological development for the production of such a filter is in the foreground. The patented cyclone filter of the company Klass Filter GmbH serves as starting point. As there is no legal situation yet that regulates the number of microplastic particles or the allowed particle size in wastewater, the goal of the particles to be filtered within the project was set at ≥10 µm. With hole diameters smaller than 10 µm high demands are made on the laser drilling process. In thin metal foils, laser percussion drilling achieves hole diameters of less than 5 µm. Due to the mechanical stress, these foils are not suitable for cyclone filters. For process development, a compromise must be found between a minimum hole size and the possible throughput. The drilling process is to be simulated with software developed at the Fraunhofer ILT, so that the drilling process can be designed considering the laser parameters laser power, pulse duration or beam radius. In order to ensure the smooth manufacture of the filters, the drilling process will be monitored by an optical method. Following the development of the technology, a prototype will be built, which will be integrated into a cyclone filter. The prototype will be tested with a test fluid and in a wastewater treatment plant.