We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Microplastics as emerging contaminants in municipal solid waste compost: Distribution, characterization, and ecological risk
Summary
Researchers evaluated microplastic contamination in compost produced at three municipal composting facilities in central Iran over a full year. They found microplastics in all compost samples, identified multiple polymer types using Raman spectroscopy, and assessed the ecological risks of applying this compost to agricultural land. The findings raise concerns that using compost made from municipal solid waste may inadvertently spread microplastic pollution to farmland soils.
The increasing abundance of microplastics (MPs) in water and soil has raised significant environmental concerns. This study evaluated the abundance and ecological risks of MPs in compost produced from three composting facilities (S1-S3) in Isfahan province, central Iran. Monthly samples were collected over a year, and MPs were extracted using an adapted protocol involving organic matter digestion with 0.05 M Fe (II) solution and hydrogen peroxide (HO), followed by density separation using saturated zinc chloride (ZnCl). Despite rigorous methods, limitations remain due to the lack of a global standard and inherent errors in existing MP extraction protocols. The extracted MPs were analyzed under a stereomicroscope, and polymer types were identified via Micro-Raman spectroscopy. Ecological risks were assessed using established indices, including the Polymer Hazard Index (PHI), Pollution Load Index (PLI), and Potential Ecological Risk Index (PERI). The results revealed that the average MPs abundance in S1, S2, and S3 were 44,267 ± 7,240, 38,500 ± 6,130, and 34,267 ± 5297 items/kg dry compost, respectively. MPs larger than 1000 μm accounted for 41 %-49 % of the total, with fragments being the most prevalent shape (49 %-51 %). Polyethylene terephthalate, polyethylene, and polyolefin were the dominant polymers in all facilities. The ecological risk indices indicated high levels of risk in all three composting sites, with potential implications for agricultural soils, soil fertility. MPs in compost may enter the food chain, raising concerns for ecosystem health. These findings underscore the significant MP contamination in compost and highlight the need for improved solid waste management strategies to reduce plastic pollution.
Sign in to start a discussion.
More Papers Like This
Microplastics identification and quantification in the composted Organic Fraction of Municipal Solid Waste
Researchers quantified microplastics in composted organic municipal solid waste from five facilities, finding contamination levels that raise concerns about compost quality and the potential transfer of microplastics to agricultural soils through organic waste recycling.
Plastics and other extraneous matter in municipal solid waste compost: A systematic review of sources, occurrence, implications, and fate in amended soils
Researchers reviewed contamination in municipal compost made from household organic waste, finding plastics are the most prevalent pollutant — with some batches containing enough plastic to deposit over 500 kg per hectare of farmland each year. Repeated use of contaminated compost builds up microplastics in soil, threatening soil health and potentially moving plastic particles into crops and food.
Identification and Quantification of Microplastics in Commercial Compost From a Wide Range of Composting Materials and Potential Environmental Impacts
Researchers identified and quantified microplastics in commercial compost derived from household waste, livestock manure, and vegetable straw using acid extraction, filtration, and FTIR spectroscopy. All compost types contained microplastics, with concentrations varying by feedstock type, raising concerns about microplastic introduction to agricultural soils via compost application.
Microplastic pollution and the related ecological risks of organic composts from different raw materials
Researchers analyzed microplastic contamination in 124 organic compost samples made from livestock manure, poultry waste, crop straw, and solid waste, finding that all types contained significant microplastic loads. Solid waste compost had the highest levels while crop straw compost had the lowest, and the particles showed signs of weathering and mineral attachment. The findings suggest that applying organic compost to farmland may be an underappreciated source of microplastic pollution entering agricultural soils.
Determination and quantification of microplastics in compost
Researchers analyzed commercially available compost products to determine how much microplastic contamination they contain. They found microplastics in all tested composts, with fibers and fragments being the most common forms, primarily made of polyethylene and polypropylene. The findings raise concerns that applying commercial compost to agricultural land may be an overlooked pathway for introducing microplastics into soil.