Good to know
Microplastics
Microplastic particles smaller than 5 mm represent a growing threat to aquatic ecosystems. Their sources are diverse, and wastewater treatment plants have been identified as significant pathways for the entry of microplastics into the oceans. In treatment plants, wastewater passes through various purification stages, but not all microplastic particles can be effectively retained. Some of these particles are discharged with treated water into rivers and ultimately into the sea. In the image, you can see a microscope image of this grinding water. (Free University of Berlin) The adsorption properties of microplastics cause pollutants such as persistent organic pollutants (POPs) to adhere to their surface. This property makes microplastics a “magnet” for pollutants that can accumulate in the marine food chain. Floating microplastics are taken up by a wide variety of marine organisms, from zooplankton to larger fish, allowing pollutants to accumulate in living organisms.
In particular, the ability of microplastic particles to penetrate cells allows them to enter the organs of marine organisms. Studies have shown that microplastics can reach the livers of fish, where they accumulate and may exert potentially toxic effects. The accumulation of microplastics and adsorbed pollutants in the liver can lead to inflammatory responses, disrupted metabolic functions, and impaired reproductive capacity.
In addition to the environmental hazard posed by the microplastic particles themselves, chemical compounds can also be released from the particles into the water and thus enter the environment. These include, among others, substances used in the manufacture of plastics, such as plasticizers and other additives. The large surface area of plastic particles facilitates the transfer of such compounds into the surrounding water. The release of such compounds, most of which are organic, into the water cycle should generally be avoided, as the environmental risks are difficult to assess and wastewater treatment plants are usually only able to remove them inadequately.
Why activated carbon?
To limit this environmental risk as well, laboratory studies were carried out by AFIN-TS GmbH to investigate the use of activated carbon for removing organic compounds in the KOSKINO filter. Activated carbon has the property of adsorbing a wide range of organic compounds and can therefore remove them from water. In the studies, grinding-water samples were treated with different amounts of activated carbon and analyzed after a defined exposure time. The samples were examined using liquid chromatography coupled with high-resolution and high-accuracy mass spectrometry (LC-HRAM-MS/MS) in a non-target screening approach. These tests showed that adding activated carbon to grinding water leads to a significant reduction in the content of organic compounds. An optimal amount for use in the KOSKINO system was also determined. The activated carbon, like the microplastic particles, can then be captured by the filter and disposed of properly.
