Abstract
The deterioration of water quality is a global issue impacting ecosystems and human health. Persistent organic pollutants (POPs), especially per- and polyfluoroalkyl substances (PFAS), are concerning due to their widespread presence in water, air, and tissues. The current study aimed at evaluating advanced oxidative hybrid systems, specifically combinations of UV with Fenton's reagent, ozone with Fenton's reagent, UV with Ferrate, and ozone with Ferrate, to effectively degrade PFAS in water samples collected from a section of Hennops River between Irene Farm in Centurion and Mount Amanzi Lodge in Hartbeespoort, in Madibeng Town. Solid phase extraction (SPE) was used for extracting, separating, and preconcentrating samples, which were later quantified using liquid chromatography-mass spectrometry (LC/MS). The results revealed that hybrid combinations, particularly the integration of ozone and the Fenton process, achieved significant degradation efficiencies, with 98.5% degradation at Hennopspride Lodge and 97.7% at the Irene dairy farm. Conversely, photolysis was the least effective technique for PFAS degradation. The analytical methodology utilised demonstrated impressive performance, with low limits of detection (LOD) ranging from 0.0033 ng/L to 0.08 ng/L and limits of quantification (LOQ) between 0.010 ng/L and 0.27 ng/L. Under optimal conditions, the methodology exhibited broad linear dynamic ranges and reliable precision, highlighting its potential for environmental monitoring and remediation. Although certain individual AOPs showed some efficacy in degrading PFAS, the hybrid methods proved more efficient, achieving higher degradation rates, reduced treatment times, and minimising both energy consumption and the quantity of oxidants required.