Mechanistic approach of SO4•−/•OH radical toward target pollutants degradation simultaneously enhanced activity and stability of perovskite-like catalyst SrCuxNi1-xO3

Abstract

• A novel catalyst SrCu x Ni 1-x O 3 were synthesized by citric solgel method. • In-situ generated reactive species SO 4 •– and • OH both play major role on degradation. • Treatment system 0.6SCN/PMS provided very low treatment cost 50.72 $/m 3 of aqueous solution. • The possible degradation pathways of acrylonitrile and acrylamide were proposed. In this study, the degradation of highly toxic pollutants acrylonitrile (ACN) and acrylamide (ACM) by peroxymonosulfate (PMS) activation with series perovskite-like catalyst SrCu x Ni 1-x O 3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were studied systematically in the batch experiments. Synthesized catalysts were characterized by various analytical techniques e.g., XRD, FTIR, FESEM with EDAX, TEM, XPS and EPR spectroscopy. Subsequently, effects of key parameters viz., PMS dosage, catalyst dosage, pH and reaction temperature were evaluated on the degradation efficiency and simultaneously evaluated the PMS utilization efficiencies along with PMS consumption. Catalyst 0.6SCN exhibited the highest catalytic activity and maximum removal of acrylonitrile (96%) and acrylamide (81%) along with 86% PMS consumption were observed at optimum operatizing conditions. In addition, stability and recyclability of 0.6SCN catalyst were assessed and removal efficiency of acrylonitrile suppressed 6% and acrylamide suppressed 11% over the fourth cycle of experiments along with very low leaching of Cu and Ni observed. Furthermore, electron paramagnetic resonance (EPR) and quenching experimental studies reveal that in-situ generated both reactive species (SO 4 •– and • OH) were accountable for the removal of acrylonitrile and acrylamide synergistically in 0.6SCN/PMS system. Reaction pathways of acrylamide and acrylonitrile degradation were proposed based on the intermediate detected through GC–MS analysis and literature studies. Finally, the operating cost of treatment process was assessed 50.62$/m 3 of wastewater in 0.6SCN/PMS system.