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IMPACT OF DIFFERENT SCREENING TECHNOLOGIES ON THE SEPARATION OF PLASTIC, METAL AND GLASS IMPURITIES FROM COMPOSTS

  • Erwin Binner - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU University, Austria
  • Peter Beigl - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU University, Austria
  • Benedikt Vay - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU, Austria
  • Rene Schwarzl - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU University, Austria
  • Marion Huber-Humer - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU University, Austria
  • Christian Zafiu - Department of Landscape, Water, and Infrastructure, Institute of Waste Management and Circularity, BOKU University, Austria
  • Pages

DOI 10.31025/2611-4135/2026.19590

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Copyright: © 2025 CISA Publisher

Abstract

The application of compost is regulated in the EU member states mainly based on the quantity of hazardous chemical elements and compounds and on physical contaminants, such as glass, metals and plastics. A large fraction of impurities is removed by screening of the rotting material usually before the composting process is started or at the end of the process. Different screening technologies are used to obtain high quality composts. However, the removal efficiency of impurities for frequently used screening technologies was not thoroughly studied so far. In this study raw compost (rotting duration 6 weeks) from a composting plant, was treated by 6, 8, and 10 mm flip-flop screens and 12 and 25 mm drum screens. The produced composts were analyzed on their properties as well as quantities of impurities. In addition, plastic impurities in fraction down to 0.63 mm were investigated for their quantity in mass, the particle number, polymer, and form type (fiber, film and fragments). The results show that all investigated screening technologies were able to remove plastic-impurities to a level below the thresholds (limit-value 0.3 % DM in the fraction > 2 mm) for composts according to the EU fertilizer regulation. The deeper analysis, however, showed that plastics of different form types were separated with different efficiencies by flip-flop and drum screens. Additionally, microscopic analyses of the separated plastics indicated that film and fiber materials that were larger than the mesh sizes were not entirely separated by screening.

Keywords

Editorial History

  • Received: 29 Nov 2025
  • Revised: 08 Apr 2026
  • Accepted: 08 Apr 2026
  • Available online: 03 May 2026

References

Albertsson, A.-C., Karlsson, S., 1988. The three stages in degradation of polymers—polyethylene as a model substance. J. Appl. Polym. Sci. 35, 1289–1302.
DOI 10.1002/APP.1988.070350515

Alessi, A., Lopes, Alice do Carmo Precci, Müller, W., Gerke, F., Robra, S., Bockreis, A., 2020. Mechanical separation of impurities in biowaste: Comparison of four different pretreatment systems. Waste Management 106, 12–20.
DOI 10.1016/j.wasman.2020.03.006

Allen, N.S., Edge, M., Mohammadian, M., Jones, K., 1994. Physicochemical aspects of the environmental degradation of poly(ethylene terephthalate). Polymer Degradation and Stability 43, 229–237.
DOI 10.1016/0141-3910(94)90074-4

Bertling, J., Bertling, R., Hamann, L., 2018. Kunststoffe in der Umwelt: Mikro-und Makroplastik. Ursachen, Mengen, Umweltschicksale, Wirkungen, Lösungsansätze, Empfehlungen. Kurzfassung der Konsortialstudie, Fraunhofer-Institut für Umwelt-, Sicherheit-und Enegietechnik UMSICHT (Hrsg.), Oberhausen.
DOI 10.2903/j.efsa.2016.4501

Bläsing, M., Amelung, W., 2018. Plastics in soil: Analytical methods and possible sources. The Science of the total environment 612, 422–435.
DOI 10.1016/j.scitotenv.2017.08.086

Braun, M., Mail, M., Heyse, R., Amelung, W., 2021. Plastic in compost: Prevalence and potential input into agricultural and horticultural soils. The Science of the total environment 760, 143335.
DOI 10.1016/j.scitotenv.2020.143335

Chojnacka, K., Moustakas, K., Witek-Krowiak, A., 2020. Bio-based fertilizers: A practical approach towards circular economy. Bioresource Technology 295, 122223.
DOI 10.1016/j.biortech.2019.122223

Cogger, C.G., 2005. Potential Compost Benefits for Restoration Of Soils Disturbed by Urban Development. Compost Science & Utilization 13, 243–251.
DOI 10.1080/1065657X.2005.10702248

Cox, K.D., Covernton, G.A., Davies, H.L., Dower, J.F., Juanes, F., Dudas, S.E., 2019. Human Consumption of Microplastics. Environ Sci Technol Environ Sci Technol 53, 7068–7074

do Carmo Precci Lopes, Alice, Robra, S., Müller, W., Meirer, M., Thumser, F., Alessi, A., Bockreis, A., 2019. Comparison of two mechanical pre-treatment systems for impurities reduction of source-separated biowaste. Waste management (New York, N.Y.) 100, 66–74.
DOI 10.1016/j.wasman.2019.09.003

EC, 2019. Regulation (EU) 2019/1009 of the European Parliament and of the Council of 5 June 2019 laying down rules on the making available on the market of EU fertilising products and amending Regulations (EC) No 1069/2009 and (EC) No 1107/2009 and repealing Regulation (EC) No 2003/2003, OJ L 170, 25.6.2019, p. 1–114

ECN 2021. Position paper: Plastics, Microplastics in Compost and Digestate (4.8.2021); Online source: https://www.compostnetwork.info/download/ecn-position-paper-plastics-microplastics-in-compost-and-digestate/ (accessed 22.11.2021)

European Compost Network, 2022. ECN Status Report 2022 - European Compost Network. EUROPEAN COMPOST NETWORK ECN e.V., Bochum (Germany). https://www.compostnetwork.info/download/ecn-status-report-2022/ (accessed 20 September 2024)

Ferreux, J., do Carmo Precci Lopes, Alice, Müller, W., Robra, S., Bockreis, A., 2020. Bestimmung und Abtrennung des Fremdstoffgehaltes von Bioabfällen mittels Siebung und Windsichtung. Österr Wasser- und Abfallw 72, 61–67.
DOI 10.1007/s00506-019-00630-2

Heyman, H., Bassuk, N., Bonhotal, J., Walter, T., 2019. Compost Quality Recommendations for Remediating Urban Soils. International Journal of Environmental Research and Public Health 16.
DOI 10.3390/ijerph16173191

Huerta Lwanga, E., Gertsen, H., Gooren, H., Peters, P., Salánki, T., van der Ploeg, M., Besseling, E., Koelmans, A.A., Geissen, V., 2016. Microplastics in the Terrestrial Ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae). Environmental Science & Technology 50, 2685–2691.
DOI 10.1021/acs.est.5b05478

Huerta Lwanga, E., Gertsen, H., Gooren, H., Peters, P., Salánki, T., van der Ploeg, M., Besseling, E., Koelmans, A.A., Geissen, V., 2017. Incorporation of microplastics from litter into burrows of Lumbricus terrestris. Environmental pollution (Barking, Essex : 1987) 220, 523–531.
DOI 10.1016/j.envpol.2016.09.096

Jank, A., Müller, W., Waldhuber, S., Gerke, F., Ebner, C., Bockreis, A., 2017. Hydrocyclones for the separation of impurities in pretreated biowaste. Waste management (New York, N.Y.) 64, 12–19.
DOI 10.1016/j.wasman.2017.03.001

Le Pera, A., Sellaro, M., Sicilia, F., Ciccoli, R., Sceberras, B., Freda, C., Fanelli, E., Cornacchia, G., 2023. Environmental and economic impacts of improper materials in the recycling of separated collected food waste through anaerobic digestion and composting. The Science of the total environment 880, 163240.
DOI 10.1016/j.scitotenv.2023.163240

Martínez-Blanco, J., Lazcano, C., Christensen, T.H., Muñoz, P., Rieradevall, J., Møller, J., Antón, A., Boldrin, A., 2013. Compost benefits for agriculture evaluated by life cycle assessment. A review. Agron. Sustain. Dev. 33, 721–732.
DOI 10.1007/s13593-013-0148-7

Prendergast-Miller, M.T., Katsiamides, A., Abbass, M., Sturzenbaum, S.R., Thorpe, K.L., Hodson, M.E., 2019. Polyester-derived microfibre impacts on the soil-dwelling earthworm Lumbricus terrestris. Environmental pollution (Barking, Essex : 1987) 251, 453–459.
DOI 10.1016/j.envpol.2019.05.037

Rillig, M.C., Lehmann, A., Souza Machado, A.A. de, Yang, G., 2019. Microplastic effects on plants. The New phytologist 223, 1066–1070.
DOI 10.1111/nph.15794

Souza Machado, A.A. de, Lau, C.W., Kloas, W., Bergmann, J., Bachelier, J.B., Faltin, E., Becker, R., Görlich, A.S., Rillig, M.C., 2019. Microplastics can change soil properties and affect plant performance. Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin, Online-Ressource

Weithmann, N., Möller, J.N., Löder, M.G.J., Piehl, S., Laforsch, C., Freitag, R., 2018. Organic fertilizer as a vehicle for the entry of microplastic into the environment. Science Advances 4, eaap8060.
DOI 10.1126/sciadv.aap8060

Zafiu, C., Binner, E., Beigl, P., Vay, B., Ebmer, J., Huber-Humer, M., 2023. The dynamics of macro- and microplastic quantity and size changes during the composting process. Waste management (New York, N.Y.) 162, 18–26.
DOI 10.1016/j.wasman.2023.03.002

Zafiu, C., Binner, E., Hirsch, C., Vay, B., Huber-Humer, M., 2020. Makro- und Mikrokunststoffe in österreichischen Komposten. Österr Wasser- und Abfallw 72, 410–420.
DOI 10.1007/s00506-020-00701-9

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