Heterogeneous Photocatalytic Degradation of Nevirapine in Wastewater Using the UV/TiO₂/H₂O₂ Process

This work sought to study the elimination of nevirapine (NVP) from synthetic wastewater using the UV/TiO₂/H₂O₂ system. The main objectives were to evaluate the influence of operating parameters, reaction kinetics, contributing reactive species, degradation pathway, and catalyst reusability. The research surface methodology (RSM) was utilized for optimizing process variables. Five process variables (pH, NVP concentration, TiO₂ dosage, H₂O₂ concentration, and irradiation time) were optimized with the responses set as NVP and Total organic carbon (TOC) removals (%), respectively. 89.23% NVP and 85.71% TOC removals were achieved after 60 min of irradiation under optimum conditions. All the experimental factors were significant for NVP removal. pH was the most dominant factor, with the highest removals obtained under acidic conditions (pH 3). NVP removal conformed to the pseudo-first-order model with a rate constant (k₁) of 0.03676 min^{− 1}. Increasing pH reduced the rate constant by 75.38%, while there was an increase of 43.55% with H₂O₂. NVP degradation was primarily driven by the ^•OH and h⁺_VB. The photocatalyst demonstrated good stability against NVP loss over four cycles. Although the UV/TiO₂/H₂O₂ process has shown promising results in removing pharmaceuticals and dyes in wastewater, its application for the degradation of ARVs remains limited. As far as the authors know, the UV/TiO₂/H₂O₂ process and RSM have not yet been reported for the degradation and optimization of NVP in wastewater, respectively. The findings of this work illustrate that the UV/TiO₂/H₂O₂ system, applied with RSM optimization, can effectively degrade and mineralize NVP in wastewater.