Per- and polyfluoroalkyl substances (PFAS), and the short-chain representative perfluorohexanoic acid (PFHxA), are persistent environmental pollutants that pose serious health risks due to their resistance to degradation, mobility, and widespread presence in aquatic systems. This study investigates the adsorption of PFHxA onto graphene-based materials synthesised from graphite using a scalable, resource-efficient route and compares their performance with three commercial reduced graphene oxides. The graphene samples were characterised by BET surface area analysis, SEM, XPS, and Raman spectroscopy, revealing significant differences in surface area, pore volume, and surface chemistry that govern adsorption behaviour. Batch adsorption experiments in different water matrices (tap water, river water, and treated wastewater) under controlled pH conditions showed that graphene materials with higher surface area and optimised oxygen-containing functional groups achieved enhanced PFHxA removal, even in complex, real-world waters. Based on the physicochemical properties of both the adsorbent and adsorbate, hydrophobic interactions may contribute to adsorption alongside pore-filling effects, hydrogen bonding, and other intermolecular forces. Among the tested sorbents, the SG-X material, with its high BET surface area and hydrophobic character, and the CG-A material, which retained high performance across a broad pH range, exhibited the most promising adsorption capacities and operational robustness. These findings demonstrate the potential of engineered graphene-based adsorbents as a sustainable remediation option for short-chain PFASs, supporting circular and low-chemical-intensity approaches to protecting water quality under diverse environmental conditions.
Shirvanimoghaddam et al. (Fri,) studied this question.