Advanced graphene-based nanotechnologies for remediation of per- and polyfluoroalkyl substances (PFAS) and microplastics in water

Abstract Per- and polyfluoroalkyl substances (PFAS) and microplastics (MPs) are certain types of persistent plastic contaminants that are a cause of concern to both the ecosystems and human health. The nanotechnologies of graphene can be used to provide a new method of eliminating these pollutants in water. The review critically evaluates recent advances, key challenges, and future directions in graphene-based nanotechnologies for PFAS and microplastic remediation in water systems. Traditional technologies often fail because they are costly, ineffective or lead to secondary pollution particularly at low levels. Alternatively, graphene materials including pristine graphene, graphene oxide (GO), reduced graphene oxide (rGO), composites, and functionalized materials have a high surface area, tunable chemistry and strong sorption and catalytic capabilities. The emerging 3D structures (i.e., hydrogels, sponges, and membranes) also use porosity to improve p-p, hydrophobic and electrostatic capture. Membrane-based separation, photocatalytic/oxidative degradation, and adsorption are important remediation processes. Under practical circumstances, performance is usually evaluated using adsorption capacity, kinetics, degradation efficiency, recyclability, and selectivity. However, practical implementation faces challenges such as aggregation, regeneration, toxicity, cost, and scalability. Surface functionalization, magnetic composites, photocatalyst integration, and multifunctional 3D designs are some of the strategies that are currently being reviewed. To go from laboratory to field applications, future research should concentrate on creating strong, multi-modal graphene composites that integrate adsorption, catalysis, and filtration while maintaining cost-effectiveness and ecological safety.