Catalytic oxidation processes for the degradation of Progesterone using V2O5 catalyst and C/Ti anode: Optimization and degradation dynamics

Abstract

Progesterone (PGT) is a steroid hormone produced naturally by humans. Advent of pharmaceuticals has given rise to synthetic production of PGT as a medicine for various pregnancy related issues. As a result of synthetic production and utilization rate of PGT, they have become an emerging contaminant in water sources worldwide. Conventional wastewater treatment is not equipped to remove steroid contaminants. Hence, current study attempted the degradation of10 mgL− 1 of PGT in water using photocatalysis (PC) followed by electrocatalytic oxidation (EC) using Vanadium Pentoxide (V2O5) and carbon coated titanium (C/Ti) anode. Characterization involved XRD and FTIR spectral studies that established the stability of the catalyst with the fact that no adsorptive removal of PGT had taken place. Optimization studies found UV-C irradiation, pH 5, 50 mg L− 1 catalyst, 180 min PC, 210 min EC and 69 mA.cm− 2 managed to accomplish 97% COD and 71.5% TOC removal. Comparative studies showed that PC + EC (UV-C) was 50% and 25% more efficient than EO and EC, respectively, for TOC removal. PC pretreatment to EC was found capable of bringing down the current consumption requirement of electrolysis by 23 mA.cm− 2. High resolution mass spectrometry (HRMS) studies were utilized to propose the degradation pathway that involved hydroxylation, demethylation, dehydroxylation and decarboxylation mechanisms.