Microplastics and Microrubbers in Soils around Two Landfills and a Municipal Solid Waste Transfer Station in the Ahvaz Metropolis, Iran

Document Type : Original Article

Authors

1 Department of Environmental Sciences and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

2 Department of Environment, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

3 Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.

4 Department of Chemistry, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.

10.22102/jaehr.2022.295115.1234

Abstract

Background: Microplastics and microrubbers are a substantial source of entrance pollutants to the environment and a cause for debate in environmental studies in soils surrounding two landfills and a municipal solid waste transfer station near the Ahvaz metropolis. Since the current information about these particles in Iranian Municipal Solid Waste Transfer Station and landfill systems is scanty, this study aimed to determine the amounts and abundance of microplastics and microrubbers in soils.
Methods: Each of the twelve sites that determined using a systematic grid sampling method had approximately 100 g of soil samples from a depth of 0-10 cm with three replications. The method used for extracting microplastics from soil samples was density separation with saturated Zinc chloride solution. The particles were investigated by the size, shape, abundance and colour. A total of 1807 microplastic and 1872.7 microrubber particles were detected from the samples. The Pearson’s correlation coefficient (r) was used for describing correlations.
Results: The highest abundance of microplastics was observed at the S5 site (325.9±26.8 items/100 g soil). The particles were categorized into fragments, foams, fibers, films and spheres. Five ranges of particle size were identified (between 1 mm≤L and L≤100 μm) in nine color categories. The 1mm≤L size class was dominant in microplastics (54%) and microrubbers (52%). The majority of the microplastics (41.8%) were white/transparent, whereas microrubbers were identified as black/gray (99.1%).
Conclusion: Contamination by microplastics and microrubbers exceeded allowable standards, compared to other Transfer Stations in the world.

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