Key factors affecting graphene oxide transport in saturated porous media

Ali Beryani; Mohammad Reza Alavi Moghaddam; Tiziana Tosco; Carlo Bianco; Seiyed Mossa Hosseini; Elaheh Kowsari; Rajandrea Sethi

doi:10.1016/j.scitotenv.2019.134224

Key factors affecting graphene oxide transport in saturated porous media

Sci Total Environ. 2020 Jan 1:698:134224. doi: 10.1016/j.scitotenv.2019.134224. Epub 2019 Sep 2.

Authors

Ali Beryani¹, Mohammad Reza Alavi Moghaddam², Tiziana Tosco³, Carlo Bianco³, Seiyed Mossa Hosseini⁴, Elaheh Kowsari⁵, Rajandrea Sethi³

Affiliations

¹ Civil & Environmental Engineering Department (CEE), Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran.
² Civil & Environmental Engineering Department (CEE), Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran. Electronic address: alavi@aut.ac.ir.
³ Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24. 10129 Torino, Italy.
⁴ Physical Geography Department, University of Tehran, 16th Azar St., Enghelab Sq, 14155-6465 Tehran, Iran.
⁵ Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave., 424, 15875-4413 Tehran, Iran.

PMID: 31493572
DOI: 10.1016/j.scitotenv.2019.134224

Abstract

This study focuses on the transport in porous media of graphene oxide nanoparticles (GONP) under conditions similar to those applied in the generation of in-situ reactive zones for groundwater remediation (i.e. GO concentration of few tens of mg/l, stable suspension in alkaline solution). The experimental tests evaluated the influence on GO transport of three key factors, namely particle size (300-1200 nm), concentration (10-50 mg/L), and sand size (coarse to fine). Three sources of GONP were considered (two commercial and one synthesized in the laboratory). Particles were stably dispersed in water at pH 8.5 and showed a good mobility in the porous medium under all experimental conditions: after injection of 5 pore volumes and flushing, the highest recovery was around 90%, the lowest around 30% (only for largest particles in fine sand). The particle size was by far the most impacting parameter, with increasing mobility with decreasing size, even if sand size and particle concentration were also relevant. The source of GONP showed a minor impact on the mobility. The transport test data were successfully modeled using the advection-dispersion-deposition equations typically applied for spherical colloids. Experimental and modeling results suggested that GONP, under the explored conditions, are retained due to both blocking and straining, the latter being relevant only for large particles and/or fine sand. The findings of this study play a key role in the development of an in-situ groundwater remediation technology based on the injection of GONP for contaminant degradation or sorption. Despite their peculiar shape, GONP behavior in porous media is comparable with spherical colloids, which have been more studied by far. In particular, the possibility of modeling GONP transport using existing models ensures that they can be applied also for the design of field-scale injections of GONP, similarly to other particles already used in nanoremediation.

Keywords: Blocking; Graphene oxide; Nanoparticle size effect; Nanoremediation; Straining; Transport in porous media.