0
Article Tier 2 Marine & Wildlife Sign in to save

Biochemodynamic Features of Metal Ions Bound by Micro- and Nano-Plastics in Aquatic Media

Frontiers in Chemistry 2018 76 citations

AI summary Read the abstract

This theoretical study modeled how metals that bind to plastic particles are slowly released back into water over time, finding that diffusion out of plastics is extremely slow. This means microplastics can act as long-term reservoirs for metals in the environment, releasing them gradually into surrounding water and organisms.

A simple model, based on spherical geometry, is applied to the description of release kinetics of metal species from nano- and micro-plastic particles. Compiled literature data show that the effective diffusion coefficients, D eff, for metal species within plastic polymer bodies are many orders of magnitude lower than those applicable for metal ions in bulk aqueous media. Consequently, diffusion of metal ions in the aqueous medium is much faster than that within the body of the plastic particle. So long as the rate of dissociation of any inner-sphere metal complexes is greater than the rate of diffusion within the particle body, the latter process is the limiting step in the overall release kinetics of metal species that are sorbed within the body of the plastic particle. Metal ions that are sorbed at the very particle/medium interface and/or associated with surface-sorbed ligands do not need to traverse the particle body and thus in the diffusion-limiting case, their rate of release will correspond to the rate of diffusion in the aqueous medium. Irrespective of the intraparticulate metal speciation, for a given diffusion coefficient, the proportion of metal species released from plastic particles within a given time frame increases dramatically as the size of the particle decreases. The ensuing consequences for the chemodynamics and bioavailability of metal species associated with plastic micro- and nano-particles in aquatic systems are discussed and illustrated with practical examples.

More Papers Like This

Article Tier 2

Effect of Polymer Aging on Uptake/Release Kinetics of Metal Ions and Organic Molecules by Micro- and Nanoplastics: Implications for the Bioavailability of the Associated Compounds

AI summary Read the abstract

Researchers developed a theoretical framework to describe how aging and degradation of plastic particles in the environment changes their ability to absorb and release metals and organic contaminants. They found that as plastics weather and break down, their capacity to pick up and later release pollutants increases significantly. The study suggests that the age and condition of microplastics are important factors in determining how much contamination they carry and deliver to living organisms.

Article Tier 2

Micro-nanoplastics and metals : Development of material models and sorption properties in natural environments

AI summary Read the abstract

This dissertation examines how micro- and nanoplastics interact with heavy metals in natural environments, developing material models to understand their sorption properties. Since plastics can act as carriers for toxic metals — concentrating and transporting them through ecosystems — the research has important implications for understanding combined pollution risks.

Article Tier 2

Uptake and Release Kinetics of Organic Contaminants Associated with Micro- and Nanoplastic Particles

AI summary Read the abstract

This theoretical paper presents a mathematical framework for modeling the rates at which organic pollutants are taken up by and released from micro- and nanoplastic particles. Better kinetic models are essential for predicting how much of a chemical pollutant actually reaches organisms that ingest contaminated microplastics versus remains bound to the plastic surface.

Article Tier 2

Sorption kinetics of metallic and organic contaminants on micro- and nanoplastics: remarkable dependence of the intraparticulate contaminant diffusion coefficient on the particle size and potential role of polymer crystallinity

AI summary Read the abstract

Researchers developed a mathematical model to describe how metallic and organic contaminants bind to micro- and nanoplastics over time, accounting for how particle size affects the process. They found that the rate at which pollutants diffuse into plastic particles depends strongly on particle size, with smaller particles absorbing contaminants much faster. The model provides a more accurate framework for predicting how microplastics act as carriers of environmental pollutants.

Article Tier 2

A Thermodynamic Approach for Assessing the Environmental Exposure of Chemicals Absorbed to Microplastic

AI summary Read the abstract

Researchers used thermodynamic and multimedia modeling to assess how microplastics influence the transport and bioavailability of persistent toxic substances in marine environments. The study suggests that chemicals with high hydrophobicity may partition to polyethylene microplastic, but overall, microplastic is likely of limited importance as a vector for delivering toxic substances to marine organisms compared to other exposure pathways.

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.

Email me about

Share this paper