We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Effects of Different-Sized Polyethylene Microplastics on Nitrogen Transformation in River Sediment-Water Systems
Summary
Researchers ran a 120-day indoor experiment to study how four different particle sizes of polyethylene microplastics affect nitrogen cycling in river sediment-water systems. They found that microplastic addition significantly altered nitrogen transformation processes, with effects depending on particle size.
As an emerging pollutant, the impact of microplastics’ physical properties on key biogeochemical cycles remains unclear. This study investigated the effects and mechanisms of four particle sizes (25, 150, 200, 500 μm) of polyethylene microplastics (PE-MPs) on nitrogen transformation in river systems through a 120-day indoor micro-cultivation experiment. Results indicate that microplastic addition significantly enhanced nitrogen partitioning from the water phase to sediments, leading to reduced total nitrogen and nitrate concentrations in overlying water. Small-sized (25 μm) microplastics strongly promoted ammonium nitrogen accumulation in sediments during long-term exposure, while large-sized (500 μm) microplastics induced dramatic fluctuations in sediment total nitrogen content, revealing complex adsorption-desorption dynamics. Correlation analysis indicates that sediment ammonium accumulation is significantly positively correlated with iron content. This study reveals that microplastics primarily disrupt nitrogen transformation processes by altering sediment microenvironments and providing microbial attachment sites, ultimately inhibiting nitrification and leading to the accumulation of nitrogen in the sediment as reduced ammonium salts. The study emphasizes that microplastic size is a key physical parameter governing its interference with the nitrogen cycle, providing crucial evidence for scientifically assessing its ecological risks.
Sign in to start a discussion.
More Papers Like This
Effects of microplastics on nitrogen and phosphorus cycles and microbial communities in sediments
Researchers found that PVC, PLA, and polypropylene microplastics altered nitrogen and phosphorus cycling in freshwater sediments by shifting microbial community composition, with effects varying by polymer type and biodegradability.
Microplastics affect organic nitrogen in sediment: The response of organic nitrogen mineralization to microbes and benthic animals
Researchers investigated how different types of microplastics affect organic nitrogen cycling in sediments, measuring the responses of key nitrogen-transforming microorganisms. They found microplastics alter the composition of organic nitrogen and suppress certain nitrogen cycling processes.
Effects of microplastics on inorganic nitrogen dynamics in surface water sediments under different disturbance intensities
Laboratory experiments showed that microplastics in sediments alter nitrogen cycling in freshwater systems in ways that depend strongly on concentration: low levels boosted ammonium release, while high levels suppressed it and amplified nitrate consumption. These disruptions to the nitrogen cycle could affect water quality and aquatic productivity, especially in systems that are frequently disturbed by dredging or flooding.
Polyethylene microplastics interfere with the nutrient cycle in water-plant-sediment systems
Researchers studied how polyethylene microplastics affect nutrient cycling in freshwater systems containing submerged plants and sediment. They found that the microplastics significantly reduced nitrogen and carbon content in plant leaves and disrupted the microbial communities in sediment responsible for nutrient processing. The study demonstrates that microplastic pollution can interfere with fundamental biogeochemical cycles that maintain the health of aquatic ecosystems.
Effects of microplastics on greenhouse gas emissions and microbial communities in sediment of freshwater systems
Researchers found that PET microplastics of different sizes significantly affected greenhouse gas emissions and microbial communities in freshwater sediments, with smaller particles (5 micrometers) notably increasing methane emissions and altering nutrient cycling over 90 days.