Stability, transport and ecosystem effects of graphene in water and soil environments

Abstract

Graphene nanomaterials (GMs), such as graphene oxide (GO) and reduced graphene oxide (rGO), have been widely applied in various fields. Due to the rapid increase in production and application, the inevitable release of GMs into water and soil environments poses potential health and ecosystem risks. Upon exposure, the behavior, transport, and fate of GMs may be altered after interacting with the relevant environmental conditions. GMs can affect the microbial communities as well. Thus, it is imperative to understand the interaction between the GMs and the environmental systems for predicting their risks. For this purpose, this review highlights the influence of the most relevant environmental factors on the stability, aggregation, and transformation of GMs in aquatic environments. Moreover, the transport of GMs and microbial communities changes have also been presented based on the recent findings. To the best of our knowledge, this review covered most of the recent related studies and will allow for accurate predictions of the fate and risks associated with GMs. In consideration of the diversity of GMs and the complexity of environmental factors, further studies should be focused on their inherent properties and amicable development.

Nanoecotoxicity assessment of graphene oxide and its relationship with humic acid

“…This could have occurred because only distilled water was used in this trial. For the remaining media, the initial absorbance of the exclusively graphene oxide suspension decreased rapidly in up to 24 h. This behavior can be explained by the fact that, because of the ionic strength of the medium, there is an increase in surface charge density and a reduction in repulsive electrostatic strength, which, as a result, causes aggregation of the material (He et al ). In the suspension of graphene oxide combined with humic acid, reductions of only 20 and 25% were observed in the initial absorbance values in ultrapure water and in L. sativa medium, respectively, after 96 h. In addition, the presence of humic acid altered the stability in the R. subcapitata , C. elegans , and Panagrolaimus sp.…”

“…Recent studies have demonstrated that the presence of humic acid can enhance the stability of graphene oxide in aquatic environments. Furthermore, it has been reported that graphene oxide can adsorb humic acid via hydrogen bonds, Lewis acid–base interactions, π–π interactions, and steric repulsions (He et al ; Clemente et al ). However, this effect was not observed in the other media examined in the present study.…”

Advancement of Ag–Graphene Based Nanocomposites: An Overview of Synthesis and Its Applications

“…It has been reported that graphene materials will cause the unfavorable changes of microbial communities and biological functions in environment . Likewise, the study on microbial communities change with Ag–graphene based nanocomposites is essential for understanding their ecosystem effects. 6)Research the fate and transport of Ag–graphene nanocomposites in environment: studies on the fate and transport of AgNPs and graphene materials have been reported, which are important to evaluate their potential risks . However, the researches on the environmental behaviors of Ag–graphene based nanocomposites are limited.…”

“…Since its discovery in 2004, the number of researches on graphene has increased at an unexpected rate. Currently, the most of graphene nanomaterials used and studied are graphene oxide (GO) and reduced graphene oxide (rGO) . GO possesses abundant oxygen‐containing functional groups, which provide the possibility for further chemical modification and functionalization.…”

“…rGO is commonly obtained by the removal of oxygen‐containing functional groups on GO with some reduction routes . The detailed information on their structures and properties can be obtained from several reviews . It has been reported that graphene nanomaterials have great application potential in various fields, such as supercapacitors, solar cells, sensors, and catalysts, etc.…”