Photocatalytic degradation of dairy effluent using AgTiO₂ nanostructures/polyurethane nanofiber membrane

Dairy effluent (DE) is environmentally toxic and needs special attention. Photocatalytic degradation of DE was studied using novel polyurethane (PU)-based membranes. Typically, silver-titanium dioxide nanofibers (AgTiO2 NFs) and silver-titanium dioxide nanoparticles (AgTiO2 NPs) were individually incorporated in PU electrospun nanofibers to overcome the mandatory sophisticated separation of the nanocatalysts, which can create a secondary pollution, after the treatment process.

These nanomembranes were characterized in SEM, TEM, XRD and UV studies. The polymeric electrospun nanofibers were smooth and continuous, with an average diameter of about 550nm, and held their nanofibrous morphology even after more than 2h of photocatalytic degradation of DE, due to the good stability of PU in the aqueous solutions, which indicates good imprisoning of the functional photocatalysts.

The PU-AgTiO2 NPs and PU-AgTiO2 NFs were effective materials for degradation of DE, even after two successive cycles. PU-AgTiO2 NPs and PU-AgTiO2 NFs showed a maximum degradation of 75% and 95%, respectively after 2h. The significant enhancement of degradation in the PU-Ag-TiO2 NPs and PU-Ag-TiO2 NFs is attributed to the photoactivity of Ag-TiO2 material under visible light irradiation.