Removal of nevirapine from wastewater using Non-Stationary continuous flow photocatalysis

This study explored the photocatalytic degradation of nevirapine (NVP), a widely used antiretroviral drug, using a continuous flow reactor system with an Ag-AgBr-LDH photocatalyst under visible light irradiation. The effect of light intensity was initially evaluated in batch mode, while the influence of photocatalyst loading, flow rate, and initial pollutant concentration was systematically assessed in continuous flow operation. Results indicated that higher light intensities enhanced degradation efficiency, confirming a strong correlation between photon availability and photocatalytic activity. The optimal performance was achieved with a photocatalyst loading of 3 g/L and a flow rate of 10 mL/min, resulting in the highest observed degradation efficiency. In contrast, elevated initial concentrations of NVP led to reduced degradation, likely due to light attenuation and increased surface adsorption that limited active site availability. A porous glass frit was employed at the reactor outlet to retain the suspended photocatalyst, ensuring continuous operation without material loss.