Graphene oxide as a component of a Permeable Reactive Barrier for aquifer pollution remediation

Groundwater contamination sources are ubiquitous, with the heavy metal ion lead being released to the aquifer systems as a common anthropogenic contaminant. Lead can cause serious damage to both human and ecosystem health. In this sense, its remediation through sorption technologies, such as Permeable Reactive Barriers (PRBs), is basic to minimize its impact. Quartz as the most common and economically heavy metal adsorbent has been widely studied. However, the new generation of potential adsorbents, here including graphene oxide (GO), has not been fully researched. Particularly, there is little research on how to set surface adsorption models of GO, with most studies limited to batch and transport experiments.

This study aimed to investigate the performance of quartz and graphene oxide (GO) as adsorbents in PPRBs. We evaluated the adsorption capacity of quartz sand and GO under different conditions through batch experiments, examining factors including pollutant concentration, pH, and competing ions. The experimental results were validated using a coupled surface complexation and precipitation model developed with the Phreeqc code, and the findings from the batch experiments will also be used as calibration data for the Phreeqc model, and the code (PEST) was used for parameter estimation.

Keywords: Graphene oxide, Heavy metal, Permeable Reactive Barriers, Surface complexation, Phreeqc.