Development of ceramic membranes with controllable PFAS mass transfer for passive sampling applications

Abstract

Polar organic chemical integrative sampler (POCIS) represents a promising passive sampling approach for the monitoring of per- and polyfluoroalkyl substances (PFAS) in water. However, the use of polymer membranes has limited the long-term application of conventional POCIS in the field. This work aimed to develop ceramic membranes with controllable PFAS diffusion and mass transfer suitable for PFAS passive sampling applications. Our results showed that PFAS diffusion through ceramic membranes was strongly dependent on membrane structures and properties, particularly membrane porosity. Through controlling membrane fabrication conditions, including particle size and morphology of the membrane material and sintering temperature, ceramic membranes with a range of PFAS diffusivities and mass transfer rates were obtained that varied by over two orders of magnitude, which substantially expanded the limits of polyethersulfone (PES) membranes. Further, modification of ceramic membranes with a thin TiO2 layer did not influence the PFAS mass transfer. Integrative passive samplers consisting of ceramic membranes and a sorbent receiving phase were then developed and assessed through calibration studies. The passive samplers showed linear uptake of PFAS over an extended period of time up to 25 days, and the PFAS sampling rates were affected by both the type of ceramic membranes and the PFAS structures. Results of this study demonstrated the proof-of-concept of the use of ceramic membranes in PFAS passive sampling applications.