Persulfate activation via iron sulfide nanoparticles for enhanced trichloroethylene degradation and its applications in groundwater remediation

Trichloroethylene (TCE) is known for its carcinogenic properties and limited environmental degradation. Therefore, TCE degradation was carried out using a catalyzed system, i.e., an advanced oxidation process (AOP) for an aqueous solution. This study focuses on activating sodium persulfate (PS) by laboratory-synthesized iron sulfide nanoparticles (FeS-NPs) with a particle size of 115.17 nm for enhanced TCE degradation. Field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analyses were employed to investigate physio-chemical properties and surface morphologies of synthesized FeS-NPs catalyst. PS/FeS-NPs exhibited outstanding performance, achieving a remarkable degradation (99.07 %) of TCE in 60 min of reaction time, surpassing the degradation demonstrated by commercially available PS/FeS (25 %). The dominant involvement of Fe transformation and SO4•ˉ, OH•, and 1O2 radicals in TCE degradation was validated through scavenging and electron paramagnetic resonance (EPR) investigation. Moreover, the PS/FeS-NPs system was found efficient (97⁓99 %) in both acidic and basic solutions, although it is noteworthy that highly basic (pH 11) mediums may impact the degradation efficiency (13.8 %). Recycling and stability experiments revealed significant efficiency of the PS/FeS-NPs system during the second run (90.02 %) and third run (68.25 %). These core revelations validate the efficiency of FeS-NPs in TCE degradation in an aqueous solution. Conclusively, the PS/FeS-NPs system encouraged TCE degradation outcomes, depicting strong potential for prolonged benefits in the remediation of TCE-polluted water.