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

Abstract

This work sought to study the elimination of NVP from simulated wastewater using the UV/TiO 2 /H 2 O 2 system. The main objectives were to evaluate the in uence of operating parameters, reaction kinetics, contributing reactive species, degradation pathway, and catalyst reusability. The research surface methodology (RSM) was utilized for optimizing process variables and for statistical analysis. Five process variables (pH, NVP concentration, TiO 2 dosage, H 2 O 2 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 under optimum conditions. All the experimental factors were signi cant 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-rst-order model with a rate constant (k 1 ) of 0.03676 min -1 . Increasing pH reduced the rate constant by 75.38%, while there was an increase of 43.55% with H 2 O 2 . NVP degradation was largely driven by the • OH and h +VB . The photocatalyst demonstrated good stability against NVP loss over four cycles. Although the UV/TiO 2 /H 2 O 2 process has shown promising results in the removal of pharmaceuticals and dyes in wastewater, its application for the degradation of ARVs remains limited. As far as the authors know, the UV/TiO 2 /H 2 O 2 process and RSM have not yet been reported for the degradation and optimization of NVP in wastewater, respectively. The ndings of this work illustrate that the UV/TiO 2 /H 2 O 2 system, applied with RSM can effectively degrade and mineralize NVP in wastewater. Article Highlights89.23%, Nevirapine and 85.71%, TOC removals were achieved using the UV/TiO 2 /H 2 O 2 process combined with RSM.The degradation process was favorable under acidic pH Nevirapine removal resembled pseudo-rst-order kinetics

Photocatalytic degradation of Emtricitabine, Lamivudine, and Tenofovir in water using the UV/TiO2/H2O2 hybrid system

“…The mixed phase TiO2 (anatase (A) 77%: rutile (R)23%) synthesized in our previous work was employed in this study (Ncube et al 2023). The authors demonstrated a band gap of 3.16 eV, which approximated 3.15 eV reported for the commercial mixed-phase TiO2-P25 (Coutts et al 2016), while being lower than the widely reported 3.2 eV for single-phase TiO2.…”

“…To prepare working standards, appropriate quantities of FTC, LVD and TFV stock solutions were spiked into ultra-pure water (UPW) in a 600 ml beaker to achieve environmentally relevant concentrations (FTC, LVD) and to match the LC/MS sensitivity (TFV) (Nannou et al 2020;Alvarez-Corena et al 2016). Mixed-phase TiO2 (77% A/23% R) synthesized in our previous work was employed as the photocatalyst (Ncube et al 2023).…”

“…Enhanced removals of textile dye and pharmaceutical residues have been achieved in other studies using UV/TiO2/H2O2 (Lan et al 2022;Collivignarelli et al 2020;Lumbaque et al 2020). In our previous work, the UV/TiO2/H2O2 was successfully utilized to degrade the ARV drug nevirapine (NVP) in wastewater, achieving ≈ 89% removals (Ncube et al 2023). These results were encouraging, considering the non-polar and hydrophobic nature of NVP.…”

“…1) was used in this study. The dimensions of the reactor and material of construction are detailed in our previous study (Ncube et al 2023).…”

“…The photocatalytic degradation method used in the study was utilized in our previous work (Ncube et al 2023). Pollutant spiked water was introduced to the reactor (Fig.…”