Environmental fate of multiwalled carbon nanotubes and graphene oxide across different aquatic ecosystems

Abstract

The industrial use and widespread application of carbon-based nanomaterials have caused a rapid increase in their production over the last decades. However, toxicity of these materials is not fully known and is still being investigated for potential human and ecological health risks. Detecting carbon-based nanomaterials in the environment using current analytical methods is problematic, making environmental fate and transport modeling a practical way to estimate environmental concentrations and assess potential ecological risks. The Water Quality Analysis Simulation Program 8 (WASP8) is a dynamic, spatially resolved fate and transport model for simulating exposure concentrations in surface waters and sediments. Recently, WASP has been updated to incorporate processes for simulating the fate and transport of nanomaterials including heteroaggregation and phototransformation. This study examines the fate and transport of multiwalled carbon nanotubes (MWCNT), graphene oxide (GO) and reduced graphene oxide (rGO) in four aquatic ecosystems in the southeastern United States. Sites include a seepage lake, a coastal plains river, a piedmont river and an unstratified, wetland lake. A hypothetical 50-year release is simulated for each site-nanomaterial pair to analyze nanomaterial distribution between the water column and sediments. For all nanomaterials, 99% of the mass loaded moves though systems of high and low residence times without being heteroaggregated and deposited in the sediments. However, significant accumulation in the sediments does occur over longer periods of time. Results show that GO and rGO had the highest mass fraction in the water column of all four sites. MWCNT were found predominantly in the sediments of the piedmont river and seepage lake but were almost entirely contained in the water column of the coastal plains river and wetland lake. Simulated recovery periods following the release estimate 37+ years for lakes and 1-4 years Disclaimer This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The views expressed in this article are those of the authors and do not necessarily represent the views or policies of the USEPA. Appendix A. Supporting Information (SI)

Fragmentation of polymer nanocomposites: modulation by dry and wet weathering, fractionation, and nanomaterial filler

“…Though not as environmentally relevant, dry weathering provides better control of released particles than wet, making it preferable when comparing release from different materials. Quantitative studies can now use the enhanced protocol to follow up on the modulation of weathering by wavelength [83][84][85] and by molecularly dissolved additives (UV-stabilizers, pro-oxidants).…”

Graphene-Based Nanomaterials Modulate Internal Biofilm Interactions and Microbial Diversity

“…However, the monitoring of environmental pollutions by GBMs is not possible yet due to technical limitations for their detection at current low concentrations in complex matrices ( Goodwin et al, 2018 ). Nevertheless, despite the lack of modeling data about their expected environmental concentrations, it is estimated that with increasing needs, GBMs could reach concentrations between 1 and 1,000 μg/L in aqueous environment ( Zhang et al, 2017 ), with an accumulation trend in sediment ( Sun et al, 2016 ; Avant et al, 2019 ). This requires to carefully evaluate the potential impact of these materials on environmental health, in order to contribute to the development of this nanotechnology in a safety and sustainable way ( Fadeel et al, 2018 ).…”

Primary culture macrophages from fish as potential experimental model in toxicity studies with multiwalled carbon nanotubes

“…The contamination of aquatic ecosystems by nanomaterials has caused great concern on the part of global health agencies (Jackson et al, 2013;Zarbin & Oliveira, 2013;Avant et al, 2019). In the coming decades, the release of carbon nanotubes (CNTs) into the environment will increase due to increase production and use of these nanocompounds in various sectors of society (Zarbin & Oliveira, 2013).…”

“…In the coming decades, the release of carbon nanotubes (CNTs) into the environment will increase due to increase production and use of these nanocompounds in various sectors of society (Zarbin & Oliveira, 2013). However, the adverse effects of CNTs on the environment, mainly aquatic organisms, are little known (Jackson et al, 2013;Avant et al, 2019). The CNTs are cylinder with hollow internal cavity and with one end closed.…”