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Comparative Study
. 2025 Mar;97(3):e70053.
doi: 10.1002/wer.70053.

Comparison of cellulolytic enzyme treatment and Fenton oxidation for analysis of microplastics in tire rubber particles

Soyoung Lee  1 , Kanako Yamamoto  2 , Tomohiro Tobino  1   2   3 , Fumiyuki Nakajima  1   2
Affiliations
Comparative Study

Comparison of cellulolytic enzyme treatment and Fenton oxidation for analysis of microplastics in tire rubber particles

Soyoung Lee et al. Water Environ Res. 2025 Mar.

Abstract

Uncertainties in the quantification of microplastics in various products arise from the applied pretreatment processes. Road dust, a significant source of microplastics, requires precise quantification methods to ensure accuracy. In this study, we examined the impact of pretreatment processes on the accuracy of microplastic quantification in road dust, specifically focusing on tire rubber particles. We compared the effects of cellulolytic enzyme (EZM) and Fenton (FT) treatments by analyzing the changes in particle number, size, shape, and identification accuracy for each treatment. Both treatments increased the number of tire rubber particles, reduced their size, and made them more spherical. Notably, the FT treatment resulted in smaller particle parameters (Feret, MinFeret, Major, Minor, and Area) compared to the EZM treatment. Identification accuracy also varied, with 89% of tire rubber particles identified after EZM treatment, compared to 51% after FT treatment. Furthermore, microplastic volume was overestimated by 4.5% following EZM treatment and underestimated by 21% after FT treatment. These findings demonstrate that pretreatment procedures significantly influence the accuracy of microplastic quantification. Our study underscores the need for further research to determine whether current microplastic estimates are accurate, as the estimated volume can change due to organic removal processes. PRACTITIONER POINTS: Pretreatment to eliminate organic materials is necessary for improving the efficiency of microplastic analysis. Tire rubber particles (TRPs) are a significant plastic material found in urban surfaces. Pretreatment can reduce the size of TRPs and lead to material misidentification of materials. Compared to the Fenton oxidation treatment, cellulolytic enzyme treatment results in less particle fragmentation and volume modification.

Keywords: microplastic; misidentification; plastic load estimation; road dust; tire.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

FIGURE 1
FIGURE 1
Morphological changes before and after EZM and FT treatments. (a) Number of particles, (b) Feret size, (c) cumulative frequency of Feret size for pooled samples of five replicates, and (d) circularity. Plots and error bars in (a), (b), (d) are average and SD for five replicates. Statistical significance (two‐way ANOVA, Tukey's test) is indicated as follows: * (p < 0.05), *** (p < 0.001), and **** (p < 0.0001).
FIGURE 2
FIGURE 2
Number of misidentified materials after EZM and FT treatment.
FIGURE 3
FIGURE 3
Identified material with the size of the particle after EZM treatment (a) and FT treatment (b), pooled for five replicates.
See this image and copyright information in PMC

References

    1. Ahmed, M. B. , Rahman, M. S. , Alom, J. , Hasan, M. S. , Johir, M. A. H. , Mondal, M. I. H. , Awual, M. R. , & Yoon, M. H. (2021). Microplastic particles in the aquatic environment: A systematic review. Science of the Total Environment, 775, 145793. 10.1016/j.scitotenv.2021.145793 - DOI - PubMed
    1. Akyildiz, S. H. , Sezgin, H. , Yalcin, B. , & Yalcin‐Enis, I. (2023). Optimization of the textile wastewater pretreatment process in terms of organics removal and microplastic detection. Journal of Cleaner Production, 384, 135637. 10.1016/j.jclepro.2022.135637 - DOI
    1. Boucher, J. , & Friot, D. (2017). Primary microplastics in the oceans: a global evaluation of sources. IUCN. 10.2305/IUCN.CH.2017.01.en - DOI
    1. Burghardt, T. E. , & Pashkevich, A. (2023). Road markings and microplastics–a critical literature review. Transportation Research Part D: Transport and Environment, 119, 103740. 10.1016/j.trd.2023.103740 - DOI
    1. Cabernard, L. , Roscher, L. , Lorenz, C. , Gerdts, G. , & Primpke, S. (2018). Comparison of Raman and Fourier transform infrared spectroscopy for the quantification of microplastics in the aquatic environment. Environmental Science & Technology, 52(22), 13279–13288. 10.1021/acs.est.8b03438 - DOI - PubMed

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