Citation: Spacilova, M.; Dytrych, P.; Lexa, M.; Wimmerova, L.; Masin, P.; Kvacek, R.; Solcova, O. An Innovative Sorption Technology for Removing Microplastics from Wastewater. Water 2023, 15, 892. https://doi.org/10.3390/w15050892 Academic Editors: Jia-Qian Jiang and Mehrab Mehrvar Received: 11 January 2023 Revised: 22 February 2023 Accepted: 23 February 2023 Published: 25 February 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). water Article An Innovative Sorption Technology for Removing Microplastics from Wastewater Marketa Spacilova 1, * , Pavel Dytrych 1 , Martin Lexa 2 , Lenka Wimmerova 3 , Pavel Masin 4 , Robert Kvacek 5 and Olga Solcova 1 1 Department of Catalysis and Reaction Engineering, Institute of Chemical Process Fundamentals of the CAS, Rozvojova 135, 165 00 Prague, Czech Republic 2 Department of Wood Processing and Biomat, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague, Czech Republic 3 Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamycka 129, 165 00 Prague, Czech Republic 4 DEKONTA a.s., Dretovice 109, 273 42 Dretovice, Czech Republic 5 Prazske Vodovody a Kanalizace, a.s., Ke Kablu 971, 102 00 Prague, Czech Republic * Correspondence: spacilova.marketa@icpf.cas.cz; Tel.: +420-220-390-280 Abstract: This study is focused on technology development for microplastic removal from wastewater using a sorption process, which would be suitable not only as a tertiary stage of purification in wastewater treatment plants but also for other waters, e.g., process water and surface water. Therefore, cheap natural materials such as zeolites and bentonites were tested as possible sorbents. This study aims not only at sorbent selection but also at their possible modification by a special water regime improving sorption efficiency and lifetime. Microplastic particles of the majority of common types of plastics were prepared by a newly developed abrasion technique from various plastic items used at home, thus microplastic particle sizes and shapes corresponded to the real microplastics found in waters. Based on results with high reproducibility, a novel method for microplastic characterization based on Raman spectroscopy in combination with SEM/EDX was developed. The removal of microplastics from waste water was tested not only at the laboratory scale but also in a developed semi-operational sorption unit at a real wastewater treatment plant throughout the year with the efficiency of over 90%. Keywords: microplastics; water treatment; sorption; scale up; bentonite 1. Introduction Microplastics in water are among the most problematic emerging pollutants and have become a major environmental issue. It is estimated that the leakage of secondary microplastics alone reaches 176,000 tons per year in European surface waters [1]. In an effort to prevent the release of microplastics into the environment, the European Chemicals Agency (ECHA) prepared a proposal to limit microplastics in products placed on the EU market in January 2019 [2], and in August 2022, the ECHA further prepared a proposal to change the list of substances subject to restrictions according to Annex XVII of the REACH Regulation [3]. Owing to these bans, it is expected that 500,000 tons of microplastics will not be released into the environment over the next twenty years. Their adoption will prevent the entry of primary microplastics; however, secondary microplastics will continue to occur in the environment and will need to be removed from the environment, not just water. Ubiquitous microplastics are ingested by aquatic creatures from microorganisms to fish (for Mullus barbatus [4] and, at the end of the food (for radish, see [5]) chain, by humans [6–12]. Four high-production-volume polymers applied in plastic (polyethylene terephthalate, polyethylene, polystyrene derivates as expanded polystyrene and acetonitrile butadiene styrene) were identified and quantified for the first time in blood [13]. Dumping Water 2023, 15, 892. https://doi.org/10.3390/w15050892 https://www.mdpi.com/journal/water