Biologically inspired solutions to micro- and nanoplastic filtration in wastewater treatment plants

Resulting from the widespread global adoption of plastic products, the ubiquitous contamination by micro- and nanoplastics (MNPs) now affects nearly every ecosystem, with aquatic environments serving as a primary sink for a vast portion of this pollution. These particles enter the food web, leading to bioaccumulation and posing a potential threat to ecosystems and human health. Conventional filtration systems exhibit limited efficiency to mitigate the growing threat of small MNPs: paradoxically, wastewater treatment plants (WWTPs) have become a significant contributor to pollution by MNPs. Addressing this challenge requires the development of more effective filtration technologies. The present work investigates sophisticated filtration mechanisms found in nature, employing two distinct biomimetic approaches to evaluate their technological translatability for the design of next-generation, highly efficient filtration systems. About 40 biological filtration principles were found of which 9 were examined in more detail. This includes a description of the central functional principles and the transfer to a conceptual solution for wastewater MNPs filtration. The work is carried out in collaboration between a university and a private engineering consultancy company and represents a novel contribution to how formal methods are applied for incorporating biological inspiration into the design process for wastewater treatment.