For years, experts have discussed the introduction of a fourth purification stage for sewage treatment plants. The reason for this is the observation that a growing number of trace substances are being found in bodies of water that cannot be filtered with conventional water treatment. These mainly comprise nitrate from agriculture and residues of pharmaceuticals, including human and veterinary drugs. Then there is a large number of other problematic substances, such as pesticides, household and industrial chemicals, polycyclic aromatic hydrocarbons (PAH), mercury, microplastics, nanoparticles, and antibiotic-resistant pathogens.
In discussions on this sensitive issue, sewage treatment plant operators point to the “polluter- pays” principle. Strict compliance with this concept is intended to reduce discharges, as the lower the amount of pharmaceutical residues discharged into wastewater, the less fertilizer that finds its way into the water cycle, and the fewer nanoparticles that are released into the environment, the lighter the impact on wastewater treatment facilities. But what happens to the residues that end up in wastewater in the meantime, before plans of this type can be implemented? And can the contamination be sufficiently reduced through prevention measures to the extent that render additional treatment processes unnecessary?
Filter systems for reducing pollution in water
At the next FILTECH, visitors will have the opportunity to experience innovative solutions that reflect the current state of the art in terms of wastewater treatment. Again in 2021, a large number of exhibitors will be presenting their products and services. Even now, the FILTECH, the most important platform for filtration and separation technologies worldwide for solid, liquid, and gaseous media, reports over 340 registered exhibitors.
In addition to a range of specialized providers, these include industry giants such as Andritz, which manufactures fine screens and decanter centrifuges as well as separation and filtration components, pumps, and control systems specially designed for wastewater treatment plants.
Companies such as Blücher manufacture process and wastewater treatment plants as well as systems for removing trace substances such as pharmaceutical residues, pesticides, and surfactants. High-precision mesh technologies manufactured by companies such as Haver; Boecker and software like Geodict from Math2Market enable the use of filters that are specifically designed for the medium and filtration requirements.
The company ECOFARIO also expects to garner a great deal of interest among visitors. The Munich-based start-up is working on implementing a technology that could virtually replace a fourth purification stage in sewage treatment plants going forward. Its High-G separator is said to be able to remove up to 99.9 percent of the microparticles found in wastewater – including adhering contaminants, drug residues, and hormones. Visitors to the stand will have the opportunity to gather information on the technology, the pilot plant, and future applications.
The Fraunhofer Institute for Laser Technology (ILT) is using a similar approach, but with a filter, which clearly defines the separation rate of all floating, suspended, and sedimentary matter and is independent of the flow. In collaboration with the companies Klass-Filtertechnik, LaserJob, OptiY, and Lunovu in a pilot project, the Fraunhofer ILT is developing a cyclone filter with a pore size of 10 micrometers, which is designed to separate microplastics from the wastewater stream in sewage treatment plants. “Our solution works on a self-cleaning basis. The particles are discharged using a vacuum process,” Andrea Lanfermann from the Fraunhofer Institute explains.
At the FILTECH, interested visitors can learn all about how the project is progressing and the underlying technology.
The topic of microplastics in wastewater and other waters is also being addressed by Wasser 3.0. The non-profit company aims to provide solutions from the world of materials science to improve water quality and recently began researching a process to agglomerate microplastics. Clumped together, microplastic particles collect on the water surface and can be skimmed off.