Janus enzymatic membrane contactor-reactor for volatile organic compounds remediation

The enzymatic remediation of hydrophobic Volatile Organic Compounds (VOCs) from water is hindered by low mass transfer of the gas phase to the aqueous phase. A resolution to this challenge is the development of a compact stripping process whereby VOCs captured in an oil phase are degraded at the oil/aqueous interface, allowing for continuous mass transfer and simultaneous degradation of the compounds. Here, a novel Janus Enzymatic Membrane Contactor-Reactor (EMCR) is demonstrated by engineering electrospun Cellulose Acetate (CA)/Poly (VinylDiFluoride) (PVDF) mat membranes selectively grafted with Horseradish Peroxidase (HRP) to support the degradation of VOCs. The membranes were tested for the diffusion of phenol in a flat-sheet configuration, connecting a feed of Poly (DimethylSiloxane) (PDMS) and an aqueous phase as permeate. The diffusion rates of the phenol across PDMS/membrane and membrane/aqueous phase interphases, as well as conversion rates with the surface-grafted HRP, were evaluated to optimise the morphology and reactivity of the enzymatic membrane reactors. The best performance was found for the system with immobilised HRP on Janus membrane activated by 1.0 v/v% of GlutarAldehyde (GA), leading phenol degradation rate of 8.7⋅10⁻⁴ ± 2.8⋅10⁻⁵ mg of degraded phenol min⁻¹ mg of enzyme⁻¹The results highlight the effectiveness of coupling the adsorption stage with an enzymatic degradation as a potential strategy for hydrophobic VOC removal from mixed solvent environments.