Following the widespread assumption that a majority of ubiquitous marine microplastic particles originate from land-based sources, recent studies identify rivers as important pathways for microplastic particles (MPP) to the oceans. Yet a detailed understanding of the underlying processes and dominant sources is difficult to obtain with the existing accurate but extremely time-consuming methods available for the identification of MPP.
Thus in the presented study, a novel approach applying short-wave infrared imaging spectroscopy for the quick and semi-automated identification of MPP is applied in combination with a multitemporal survey concept. Volume-reduced surface water samples were taken from transects at ten points along a major watercourse running through the South of Berlin, Germany, on six dates. After laboratory treatment, the samples were filtered onto glass fiber filters, scanned with an imaging spectrometer and analyzed by image processing.
The presented method allows to count MPP, classify the plastic types and determine particle sizes. At the present stage of development particles larger than 450 μm in diameter can be identified and a visual validation showed that the results are reliable after a subsequent visual final check of certain typical error types. Therefore, the method has the potential to accelerate microplastic identification by complementing FTIR and Raman microspectroscopy. Technical advancements (e.g. new lens) will allow lower detection limits and a higher grade of automatization in the near future.
The resulting microplastic concentrations in the water samples are discussed in a spatio-temporal context with respect to the influence (i) of urban areas, (ii) of effluents of three major Berlin wastewater treatment plants discharging into the canal and (iii) of precipitation events. Microplastic concentrations were higher downstream of the urban area and after precipitation. An increase in microplastic concentrations was discernible for the wastewater treatment plant located furthest upstream though not for the other two.
The current study examines the contamination of microplastics in three greenhouse types: abandoned, normal, and simple. The findings revealed that the abundance of microplastics was found to be the highest in the abandoned greenhouse, followed by the normal greenhouse and simple greenhouse. The mean abundance of microplastic organic fertilizer and irrigation water was also high.[…]
The study examines the distribution of residual film after eight years of film mulching in mid-April 2018. Results from the study revealed that eight years of mulching significantly increased the quantity of agricultural mulch film residues in the soil. The size of residual film fragments was found to vary from 0.25 cm2 to 109 cm2,[…]
A study in Yuanmou County, Yunnan Province, investigated microplastic pollution in different land uses, including facility farmland, traditional farmland, orchard, grassland, and woodland. Results showed a significant difference in microplastic abundance and characteristics between different land use types. Facility farmlands, traditional farmlands, and orchard lands had higher microplastic abundance than grasslands and woodlands. The main[…]
The study analysed 225 soil samples from maize planting zones in northern China, revealing that long-term plastic film mulching increases microplastic pollution in agricultural soils. The abundance of microplastics was significantly higher in mulched soils (754 ± 477 items kg-1) than in non-mulched soils (376 ± 149 items kg-1). The length of time with film[…]
The study examined the relative abundances and morphological distributions of microplastics (MPs) in water, sediments, and farmland soils in the Caohai Lake region. The estuary in the study area was considered a potential sink for MP transportation. Transparent and black MPs accounted for a large proportion of MPs in the five environments, with possible sources[…]