Fate and Transformation of Graphene Oxide in Estuarine and Marine Waters

Abstract

The possibility of graphene oxide (GO) exposure to the environment has spurred several studies investigating the fate of this nanoparticle (NP). However, there is currently little or no data on the fate of GO in estuarine and marine waters. This study investigated the aggregation, sedimentation and transformation of GO in saline waters, considering the role of salinity (0-50 ‰), light (visible light and solar irradiation), aging, among others. The attachment efficiency of GO reached unity at 1.33 ‰. The sedimentation rate of GO increased with salinity up to 10 ‰ after which it decreased due to formation of ramified GO agglomerates and media density. Based on the sedimentation rate determined at 30 ‰ (0.121 m/d), the residence time of GO agglomerates in the euphotic zone of typical open oceans will exceed 500 days. Aging in the presence of visible light increased the relative abundance of the GO's aromatic (C−C/C=C) fraction, reducing the NP. Reduction of GO in visible light was confirmed via UV-Vis and Raman spectroscopic techniques. Reduction of GO was faster under solar irradiation. This study demonstrates that when introduced into saline waters GO will undergo a range of transformations affecting its fate and potential effects to aquatic organisms.

Ecotoxicological impact of graphene oxide: toxic effects on the model organism Artemia franciscana

“…Thus, in saline waters, GO could undergo some transformations affecting its potential effects on aquatic organisms. 39 In the present work, A. franciscana was used as a model organism to study the possible ecotoxicological effect of GO, prospectively to its increasing future release into the environment. A. franciscana was exposed to GO at concentrations (1, 10 and 100 μg mL −1 ) selected on the basis of literature data on the toxicity of carbon-based nanomaterials to aquatic organisms.…”

Assessing the environmental effects related to quantum dot structure, function, synthesis and exposure

“…There are currently no studies on the agglomeration and sedimentation of carbon and graphene QDs in natural waters, but a study of graphene oxide (GO) predicts that it will take almost two years for them to settle out of the euphotic zone of natural seawater. 219 On the other hand, fullerene initially (1-3 weeks) rapidly sedimented in lake waters due to the formation of fullerene-dissolved NOM This journal is © The Royal Society of Chemistry 2022 hetero-agglomerates, after which settling was slow for several months. 220 Thus, depending on the behavior of carbon-based QDs in natural waters, pelagic organisms may be exposed to more persistent carbon-based QDs for a long time.…”

Fate of environmental pollutants: A review

“…Fate of graphene oxide, which is used in consumer and industrial products as an antibacterial agent, was studied in marine and estuarine waters under various salinity, light, and aging conditions (Adeleye, Ho, Zhang, Li, & Burgess, 2019). Salinity concentration up to 10% increased the sedimentation of graphene oxide, after which the sedimentation decreased due to formation of agglomerates.…”