Heteroaggregation of nanoplastic particles in the presence of inorganic colloids and natural organic matter

Abstract

The presence and accumulation of micro- and nanoplastics in marine and fresh waters represent a huge environmental concern.

Influence of nanoplastic surface charge on eco-corona formation, aggregation and toxicity to freshwater zooplankton

“…We hypothesised that: (i) particle aggregation, bio-reactivity and ecotoxicological outcome will depend on their primary surface functionalization and charge; (ii) NOM found in freshwaters will interact with the particles and will form eco-corona, which will affect both their aggregation and interactions with bio-interfaces; (iii) as a consequence NOM will reduce the particle toxicity and protect the organisms from nanoplastic-induced stress. We also assumed that the nanosphere behaviour and induced effects differ from those of natural particles given their significant physical and chemical difference in particle morphology, heterogeneity, surface charge (Oriekhova and Stoll, 2018). As a result, the residence times, the interactions with freshwater zooplankton, NOM, etc.…”

Strategies for determining heteroaggregation attachment efficiencies of engineered nanoparticles in aquatic environments

“…Finally, heteroaggregation also plays an important role in the fate of other particulate contaminants, such as for example nano-and microplastics. [115][116][117][118] Efforts to improve the study of heteroaggregation will therefore benefit other fields as well.…”

Controlled protein mediated aggregation of polystyrene nanoplastics does not reduce toxicity towards Daphnia magna

“…Other types of natural organic material may also interact differently with the polystyrene surface and the amine group, creating aggregates with different size, morphology and chemical stability and thereby affect the toxicity in different ways. For example, 53 nm amine modified polystyrene form large micrometer sized aggregates when mixed with alginate (polysaccharides), 35 whereas 89 nm amine modified polystyrene particles increased little in size in algae conditioned media, but formed aggregates about 300 nm in medium conditioned by D. magna. 34 However, as the concentration of particles and biomolecules will influence both the aggregation mechanism and final aggregation size, more data is needed to compare the fate of particles in different environments.…”

“…[26][27][28][29] The toxicity of polystyrene nanoplastics are strongly size-dependent and nanoplastics between around 20 to 50 nm are often found to be more toxic than larger sizes. 22,[29][30][31][32] When entering a natural environment, the nanoparticles are interacting with the surrounding biomolecules forming large heteroaggregates, [33][34][35][36] which may affect the toxicity of the nanoparticle. 33,34,36 The interactions change the presented surface chemistry as the particles are covered with various biomolecules.…”

“…This is interesting as positively charged model polystyrene nanoparticles are reported to be more toxic than negatively charged ones, 29,34,36 although the effect of the interactions differ. Another outcome from the interactions with biomolecules is that nanoparticles will be part of larger aggregates, [34][35][36] which possibly can diminish the nano-size properties. However, little is known on how aggregation of nanoplastics changes size dependent effects.…”