We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Separation and identification of microplastics from soil and sewage sludge
AI summary Read the abstract
Six agricultural soils and three sewage sludges were tested with multiple MP extraction protocols including density flotation with NaCl, ZnCl₂, and NaI, with H₂O₂ pre-digestion of organic matter significantly improving recovery. The study identifies optimal conditions for extracting microplastics from high-organic-matter samples and highlights the inadequacy of water-based protocols for complex matrices.
Soil and sludge are important pools for microplastics (MPs), however standard separation methods for MPs from these pools are still missing. We tested the widely used methods for MPs extraction from water and sediment to six agriculture surface soils and three sewage sludges from municipal wastewater treatment plants and included an additional pre-digestion procedure with 30% HO before floatation to remove soil or sludge organic matter (OM). Extraction efficiency of MPs were evaluated under different separation conditions, including floatation solution (NaCl, ZnCl, and NaI), filtration membrane, and oxidation solution. Results showed that HO pre-digestion significantly increased MPs extraction in soil and sludge, especially the samples with high OM contents, particularly sludge. Floatation solution with higher densities recovered more MPs. The extra released MPs were mainly small fibrous MPs, probably because they are easily retained by aggregates. Our results provide an feasible separation method for MPs in soil and sludge, i.e., pre-digestion with 30% HO at 70 °C, floatation with NaI solution, filtration through nylon membrane, and further oxidation with 30% HO + HSO or 30% HO at 70 °C. About 420-1290 MP items/kg soil were detected in soil samples, while much higher numbers (5553-13460 MP items/kg) were found in sludge samples. The dominate morphology of MPs was white fiber with a size of 0.02-0.25 mm, while the main types of MPs, identified by a micro-Fourier transformed infrared spectroscopy (μ-FTIR), were polyethylene and polypropylene in soil samples and polyethylene, polyethylene terephthalate, and polyacrylonitrile in sludge samples.
More Papers Like This
Extraction and decontamination of microplastics from high organic matter soils: A simple, cost-saving and high efficient method
AI summary Read the abstract
Researchers developed and validated an optimized method to extract microplastics from organic-rich soils, finding that zinc chloride flotation combined with a dilute sulfuric acid-hydrogen peroxide digestion achieves 96-102% microplastic recovery while preserving the plastic particles intact. This practical, low-cost protocol fills an important methodological gap for studying microplastic contamination in agricultural soils where high organic matter typically interferes with detection.
Optimization of a method used for extracting microplastics from an organic matter-rich matrix and isolated particles assessment
AI summary Read the abstract
Researchers optimized a method for extracting microplastics from sewage sludge — a challenging organic-rich matrix — by combining density separation and chemical digestion steps, improving recovery rates and enabling more accurate characterization of sludge-associated microplastics.
Methods for separating microplastics from complex solid matrices: Comparative analysis
AI summary Read the abstract
Separation methods for extracting microplastics from complex solid matrices including soil, sediment, and sludge were systematically compared, evaluating density separation, oil extraction, electrostatic separation, and other approaches. The review provides guidance for choosing appropriate separation methods depending on matrix composition and target microplastic characteristics.
Microplastics in solid matrices of the environment
AI summary Read the abstract
This research evaluated the sorption kinetics of pharmaceutical compounds onto polystyrene and polyethylene microplastics, finding that hydrophobic drugs showed preferential partitioning onto plastic surfaces relative to water. The study concludes that microplastics may alter the environmental fate and bioavailability of pharmaceutical contaminants in aquatic systems.
A rapid staged protocol for efficient recovery of microplastics from soil and sediment matrices based on hydrophobic separation
AI summary Read the abstract
Researchers developed a four-stage microplastic extraction device using a hydrophobic separation principle and tested three extracting solutions for recovering MPs from loam soil, sandy sediment, and muddy sediment matrices. Corn oil-in-NaCl solutions combined with aeration achieved the highest MP recovery rates across all three matrix types, offering a rapid alternative to existing digestion-based methods.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.