Author(s): Yang Gao
Email (s): gaoyang@csust.edu.cn
Institution or organization of origin: Changsha University of Science & Technology
Country: China
Abstract
In this study, we comprehensively and critically discuss the aggregation mechanism of the commercial graphene oxide (CGO) in surface aquatic environments. The aggregation kinetics and critical coagulation concentration of CGO was obtained through time-resolved dynamic light scattering and batch technique over a wide range of water types. By employing transmission electron microscopy and elemental mapping, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, we studied the effects of cations in natural waters on the microstructure transformation, element content and distribution, and oxygen-containing functional groups vibrations of IGO.
The aggregation of CGO in natural water is induced mainly by Ca2+ via complexing. While the Na+ with higher concentration plays a more important role than Mg2+ in inducing the aggregation via electric double layer suppression. The Ca2+ has mainly interaction with C−COOH, while Mg2+ has more effect on the C−OH. Na+ has less effect on the oxygen containing function group but decrease the C/O ratio in contrast with Mg2+/Ca2+/natural water, indicating the different inducing mechanism.Furthermore, the specific biological effect of CGO in the Xiangjiang river were determined by biological diversity analysis. The microbial community and species richness in Sediment was enriched. The aggregation and sedimentation process of CGO has more effect on the lower abundance phyla. This study looks forward to provide pivotal knowledge to predict the environment fate and biological effect of CGO more accurately in natural surface water.