We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Calcium carbonate deposits and microbial assemblages on microplastics in oligotrophic freshwaters
Summary
Researchers found that microplastics in oligotrophic (low-nutrient) freshwaters accumulated calcium carbonate coatings formed by microbial activity, which increased particle density and altered their environmental behavior. This coating process could change how microplastics settle or travel through water bodies, affecting where they concentrate in ecosystems.
Microplastics are solid polymer particles with a wide variety of surface properties, found in most waterbodies, and known as carriers of distinct microbial communities affecting the fate of the particles in the environment. Little is known about the formation of mineral deposits on microplastics and how these deposits connect to microbial assemblages and affect the physicochemical properties of the particles. In addition, most of the available research on this topic is based on large microplastics with sizes between 100 μm and up to 5 mm, rather than the small microplastics often found in drinking water sources. To narrow this gap in our understanding of environmental effects on small microplastics, two types of small microplastics made of two distinct polymers, poly(methyl methacrylate) (PMMA) and poly(tetrafluoroethylene) (PTFE) with sizes ranging from 15 to 150 μm, were incubated for six months in unprocessed and processed drinking water with increasing ionic concentration to allow for the formation of mineral deposits and microbial assemblages. Spatially resolved analysis with fluorescent in situ hybridization and confocal Raman microscopic imaging revealed deposits of calcium carbonates and scattered microbial assemblages on all microplastics, with structure, extend, and microbial association with the carbonates depending on the respective microplastic. Notably, PTFE floatation was overcome after three months in unprocessed drinking water but remained unchanged in processed drinking water, whereas PMMA appeared unaffected, indicating that the fate of microplastics in the environment may depend on polymer type and the encountered aquatic conditions forming mineral and microbial attachments to the particle surface.
Sign in to start a discussion.
More Papers Like This
BiocalcificationInduces the Preferential Settlingof Small Buoyant Microplastics in Freshwater
Researchers found that biocalcification processes involving Microcystis aeruginosa and calcium ions promote the preferential settling of small buoyant microplastics in freshwater, with incubation experiments revealing how algal-induced mineral precipitation accelerates vertical transport of particles that would otherwise remain suspended.
Impacts of Biofilm Formation on the Fate and Potential Effects of Microplastic in the Aquatic Environment
Researchers reviewed how biofilm formation on microplastic surfaces affects the fate and potential ecological effects of microplastics in aquatic environments, finding that biofilms alter particle buoyancy, surface chemistry, and interactions with organisms.
Heterogeneous aggregation of microplastics and mineral particles in aquatic environments: Effects of surface functional groups, pH, and electrolytes
Researchers studied how microplastics clump together with soil and rock minerals in water, finding that positively charged minerals bound to plastic particles nearly three times more effectively than clay minerals, and that low pH and calcium ions dramatically accelerated aggregation. Understanding these dynamics helps predict where microplastics will settle or stay suspended in rivers, lakes, and aquifers.
Impact of Biofilm Formation on Microplastic Behaviour in Aquatic Environments: An Comprehensive Review.
This review examines how biofilms — communities of microorganisms that coat microplastics — change the behavior of plastic particles in aquatic environments, affecting how they move, sink, and interact with ecosystems. Understanding biofilm formation on microplastics is key to predicting where these particles end up and what risks they pose to water quality and aquatic life.
Carbonate mineral precipitation enhances microplastic deposition in karst rivers globally
Scientists found that tiny plastic particles in rivers stick to calcium-based minerals and sink to the river bottom, especially in areas with limestone and similar rocks. This natural process acts like a filter that traps microplastics before they reach the ocean, which could be good news since it reduces the amount of plastic pollution flowing into marine food chains. Understanding this process could help us develop better ways to remove microplastics from rivers in different geological regions.