Photocatalytic degradation of perfluoroalkyl substances in water by using a duo-functional tri-metallic-oxide hybrid catalyst. (April 2022)

• Record Type: Journal Article
• Authors: Samuel, Melvin S.; Shang, Mingwei; Niu, Junjie
• Is Part Of: Chemosphere. Volume 293(2022)
• Publication Date: 2022-04
• Subjects: Adsorption -- Perfluoroalkyl substances (PFASs) -- Photocatalytic degradation -- Water treatment; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.133568
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The recalcitrant nature of perfluoroalkyl substances (PFASs) urges scientists to discover solutions to permanently remove PFAS contaminations from water with less energy in contrast to incineration. Herein, a duo-functional tri-metallic-oxide ( f -TMO) hybrid photocatalyst was developed via a facile process, which displayed both high adsorption capacity and high defluorination rate of a series of PFASs including PFOA, PFOS, PFHpA, PFHxA and PFBA due to the generated holes/electrons (h + /e − ) and multi-radicals such as O2 - and SO4 - . Particularly the Langmuir adsorption capacities up to 827.84 and 714.46 mg g −1 along with the adsorption efficiency of 99.8% and 99.4% for PFOS and PFOA were respectively achieved. A defluorination ratio of as high as 74.8% with PFOA and a ratio up to 67.6% with PFOS were respectively received. Over 98% PFOA molecules were degraded within as fast as 15 min under initial concentrations ranging from 1 ppb to 1000 ppb, which demonstrates an excellent degradation kinetics. As for the sulfonic acid of PFOS, an as high as 95.5% degradation efficiency was obtained within 300 min. The degradation rates were 4.5 mg L −1 h −1 for PFOA and 0.54 mg L −1 h −1 for PFOS, respectively. In parallel, the f -TMO photocatalyst still exhibited a >96.2% degradation efficiency after eight regeneration cycles. The high physical adsorption capacity and high defluorination rate make this f -TMO catalyst promising applications in removing various PFASs from a broad range of residential and industrial water systems. Highlights: High adsorption capacity of 827.8 and 714.5 mg g −1 for PFOS and PFOA, respectively. High removal efficiency of 99.8% and 99.4% for PFOS and PFOA, respectively. Defluorination ratios of 74.8% with PFOA and 67.6% with PFOS were received. Fast degradation kinetics under low PFAS concentrations.