We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Tackling microplastic contamination in sewage sludge: Optimizing organic matter degradation, quantifying microplastic presence, and evaluating ecological risks for sustainable agriculture
Summary
Researchers optimized a Fenton reagent-based method to remove 86.6% of organic matter from sewage sludge, enabling more accurate quantification of microplastics in the samples. Analysis of sludge from 14 treatment plants in Ahmedabad, India revealed microplastic concentrations ranging from 2,430 to 227,200 particles per kilogram, with small fibers and fragments being the most abundant. Ecological risk assessments indicated extreme hazard levels, raising concerns about using contaminated sewage sludge as agricultural fertilizer.
The omnipresence of Microplastics (MPs) is a growing global concern. Using sewage sludge as fertilizer for soil amendment can be a potential source of MPs in agricultural soil if sludge contains MPs. Sludge is a complex matrix rich in organic matter, which hinders MPs separation. For maximal organic matter degradation, in this study, the application of Fenton reagents optimized for (Fe/HO) molar ratios, i.e., 1/2, 1/4, 1/6, 1/8, and 1/10. The results show that a molar ratio of 1/2 of Fe/HO can remove 86.6 % of the organic matter in the sewage sludge. The greenness of the optimized method was assessed and compared to available methods using AGREEprep software. The method achieved a greenness score of 0.61, significantly higher than the highest score of 0.45 among the previously reported optimized methods. This optimized method was used in the analysis of MPs in sewage sludge from 14 sewage treatment plants in Ahmedabad. Also, the ecological risks due to the application of such sludge in agriculture were assessed. MPs analysis reveals variability in MPs contamination ranging from 2.43 to 22.72 × 10 units/kg of sludge. Small-sized MPs (0.05-0.25 mm) constitute the highest proportion (65 %), predominantly comprising fibers and fragments. From a chemical composition point of view, six different types of MPs are identified, among which PU, Nylon, HDPE, and PP are the most abundant. Ecological risk assessment indicated extreme hazards in terms of the potential ecological risk index being higher than 1200 for all the sludge samples due to the abundance of MPs, specifically of PU and Nylon.
Sign in to start a discussion.
More Papers Like This
Validation of a Method for Extracting Microplastics from Complex, Organic-Rich, Environmental Matrices
Researchers tested four common laboratory methods for extracting microplastics from complex samples like soil and sewage sludge to determine which best preserves the plastic particles during analysis. They found that Fenton's reagent was the most effective approach, successfully removing organic matter without damaging the plastic particles. The study provides important methodological guidance for standardizing microplastic research in challenging sample types.
Hidden contaminants: Unveiling the content of microplastics in municipal sewage sludge that may affect soil ecosystems
Researchers analyzed sewage sludge from two municipal treatment plants and found up to 116,000 microplastic particles per kilogram of dry sludge, with fiber-shaped and film-shaped particles dominating each plant respectively — highlighting the risk of spreading microplastic contamination to farmland when sludge is used as fertilizer.
Oil-based extraction as an efficient method for the quantification of microplastics in environmental samples
Researchers validated an oil-based extraction method for pulling microplastics out of sewage sludge and organic-rich soils, finding that pre-treating samples with Fenton's reagent (which destroys organic matter) improved recovery rates to nearly 100% for some plastic types. The study advances efforts to standardize microplastic measurement in complex environmental samples where current methods vary widely.
A novel method for organic matter removal from samples containing microplastics
Researchers developed a novel organic matter removal method for wastewater treatment plant sludge samples containing microplastics, demonstrating that the approach is more time- and cost-effective than existing techniques while preserving microplastic integrity for accurate quantification and identification.
Optimization of a method used for extracting microplastics from an organic matter-rich matrix and isolated particles assessment
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.