The definition of microplastics generally refers to small plastic particles smaller than five millimetres. However, there is still no official definition or complete agreement among experts from science, industry or politics. The lower limit for these microplastic particles in terms of size is nanoplastics. Nanoplastics describe particles in dimensions smaller than 100 nanometres, which, however, are very difficult to detect or find using current analytical methods.

For example, the European Food Safety Authority (Efsa) defines plastic particles from a size of 0.1 micrometres to five millimetres as microplastics. Current reports in the mass media have anchored the public's view of the size "smaller than five millimetres" in people's minds.

Microplastics are all synthetic plastics of less than 5 mm, which are released into the environment by human beings or human-driven processes.

Today, far more than 200 different types of plastics are known, which, however, can be completely different in their properties within the types of a class. For example polyethylene (PE). With PE, polymer chemists distinguish between the following types: LLDPE, LDPE, MDPE, HDPE, HMWPE, and UMHWPE. All of them have different properties, are produced in different processes and have different areas of application.

When we talk about microplastics, we are talking about types of plastics, their production, processing and conversion processes. All of a sudden, an unbelievably large number of different products/particles are in question.

Between 1950 and 2015, around 8.3 billion tons of plastics were produced worldwide – equivalent to around 1 ton per capita of the world's population. Half of this was produced in the last 13 years.

Some of these microplastic particles already enter the environmental cycle during the manufacture of products containing plastic or made of plastic. This form is known as primary microplastics. However, the largest proportion of microplastic particles is produced by physical-chemical processes in the environment itself, e.g. solar radiation, fragmentation by wind or storm or under the influence of water. A considerable proportion of this is caused by abrasion of e.g. car tires, bitumen in asphalt, shoe soles or the washing of textiles containing plastics. Microplastics are also released into the environment during waste disposal itself or through breezes blowing on sports fields and playgrounds with plastic coverings and thus into water bodies or our wastewater. This form is called secondary microplastics.

A recent study by Fraunhofer Umsicht estimates total emissions of microplastics in Germany at around 330,000 tons per year, divided between 60-70% microplastics produced during the use phase, 5-10% intentionally used microplastics and 25-30% macroplastics (waste).

Due to the immense pressure of the global public, triggered by the corresponding coverage in all relevant media, the number of enquiries to well-known national and international institutions such as the World Health Organization (WHO) or the Federal Institute for Risk Assessment (BfR) is increasing. Even Stiftung Warentest is currently taking part in the discussion regarding a possible health hazard posed by microplastics. Since there are no reliable and verified long-term studies on the subject worldwide, one should be more cautious with general statements.

Plastics are not natural products, but artificially produced materials. They are mainly extracted from natural gas, crude oil or coal and in most cases are not or only very slowly naturally degradable. In processing products, many plastics are sometimes supplemented with toxic additives such as UV stabilizers containing heavy metals, substances containing bisphenols or plasticizers, just to name a few. Plasticizers, for example, are now regarded as substances of very high concern because they have been shown to have a harmful effect on the endocrine system and can endanger fertility. All these auxiliary substances and additives are released during use and through improper disposal. These processes can take place both in the environment and in the human body, as a recent study by the Federal Environment Agency and the Robert Koch Institute showed.

Since 2012, we have been working with hybrid silica gels as part of various research projects at the university, where Dr. Katrin Schuhen worked as a junior professor until May 2018. At that time, we started with investigations of this material class with regard to the removal of dissolved organic-chemical compounds from our (waste) water (drugs, drug residues, pesticides, etc.). In 2016, we started the project Wasser 3.0 PE-X.

On the basis of Dr. Katrin Schuhen´s chemical background, in particular polymer science, combined with intensive research in the field of organic and ecological chemistry, she developed a concept with her PhD student Adrian Herbort, which was further developed over three years into the "Wasser 3.0 PE-X" process.

At the start, there was kind of "wish list", a collection of ideas, which clearly formulated the objective from the beginning of the work: The procedure should be suitable for everyday use, practice-oriented, cost-effective, efficient, stable in continuous operation and, above all, applicable everywhere in the world. As the icing on the cake, we wanted to remove microplastics from the surfaces and not via the sediment.

Our overriding goal was to use an innovative approach to solve the increasing global problem of microplastic contamination in our water and thus in our food.

The mode of operation is a complex matter based on physical-chemical laws and processes that we harness. Presenting the state of the art in an understandable form: Under Wasser 3.0 PE-X, we have developed a novel separation technique that triggers particle growth – an increase in volume and thus in size – in microplastics. This increase in volume makes it easier to separate the microplastics from the (waste) water.

This concept for the sustainable removal of micro- and nanoplastics is based on a three-step synthesis: the identification of particles through a water analysis before each cleaning process, the triggering of particle growth through the addition of chemical substances that are not harmful to the environment or health, and finally the filtering out or skimming off of the resulting aggregates. At the end of the (waste) water purification process, there is microplastic-free water.

In summary: We turn many small microplastic particles into a few larger aggregates in one material technology step, which float on the surface and can be easily removed.

Wasser 3.0 PE-X can be used wherever there is a need to remove microplastics from (waste) water, in sewage treatment plants as well as in industrial process plants, in private households or in seawater utilization processes.

Our Wasser 3.0 solutions – like our water bodies – do not stop at borders, but are ideally suited for international use. The process we have developed makes it possible for the first time to efficiently remove microplastics and other micro pollutants. It is scalable, adaptable regardless of location or country, and can also be combined to prevent the pollution of microplastics and dissolved micro pollutants in the ecosystems of this world. Any freshwater and saltwater environment can benefit sustainably from our process. We develop solutions for the global market.

We assemble our entire technology in mobile containers, which are easy to install, do not take up a lot of space, the electricity costs are kept to a minimum and the client only needs to provide a supply line and water drainage. Compared to other processes, the entire process is low-maintenance, the operating costs depend on the degree of contamination of the water, and the acquisition costs are manageable.

The result at the end of the entire process is clean water, secondary recycling of the waste products and protection of the sewage sludge against contamination by microplastics, which also has a positive effect on the overall costs.

This is an important aspect which, unfortunately, also gives a completely false picture of the reality surrounding microplastics in the public eye. Several studies have investigated the ability of conventional and innovative purification technologies to remove plastics from (waste) water. And yes, these studies show that conventional clarification treatments can reduce a high percentage - between 90 and 98 percent - of existing microplastic particles. However, such a conventional wastewater treatment plant is not a self-contained microcosm, but connected to a public ecosystem. Unfortunately, these studies very often neglect to communicate such positive research results that most microplastic particles are removed from the wastewater, but these particles get into the sewage sludge and via the use of this sewage sludge, e.g. as fertilizer in agriculture, into the ecosystem. Thus, one cannot speak here of an efficient, sustainable removal of microplastics, but of a shift of the problem from water to land and from the land back into the water, e.g. through precipitation.

In addition, and this is an aspect that should not be neglected, microplastics within the wastewater treatment plant do not sink completely into the basins, or only behave one-dimensionally. Microplastics are a mixture of many different components, some plastics sink into the sludge, and others float or remain in suspension and are not removed within the treatment stages, which leads to final clarification. Again, there is no 100% guarantee that the particles will not enter the receiving waters and then be flushed back into the ecosystem.

What we are aiming for with Wasser 3.0 with the addition of microplastic removal is that we protect the sewage sludge and at the same time upgrade it. Because we can also remove other pollutant loads upstream and thus offer a platform for a sustainable use of the sewage sludge.

We want to close material cycles and not obstruct opportunities through one-way street actionism. Cradle-to-cradle instead of cradle-to-grave.

We at Wasser 3.0 regard the topic of "water and wastewater purification" as a holistic process or contribution to a sustainably better environment. Therefore, we do not limit ourselves to the removal of microplastics. We offer market-ready solutions for the removal of pharmaceuticals, industrial chemicals, heavy metals, pesticides, hormones, X-ray contrast agents and other pollutants. We also combine our processes with existing technology, for example with absorption processes using powdered activated charcoal. Our processes are coordinated with each other and individually adapted to the respective (waste) water quality. In this way, we guarantee a solution tailored to every requirement or every plant – whether singular, combined or adaptive.