Biochar-Supported FeS/Fe3O4 Composite for Catalyzed Fenton-Type Degradation of Ciprofloxacin

Abstract

The Fenton-type oxidation catalyzed by iron minerals is a cost-efficient and environment-friendly technology for the degradation of organic pollutants in water, but their catalytic activity needs to be enhanced. In this work, a novel biochar-supported composite containing both iron sulfide and iron oxide was prepared, and used for catalytic degradation of the antibiotic ciprofloxacin through Fenton-type reactions. Dispersion of FeS/Fe 3 O 4 nanoparticles was observed with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). Formation of ferrous sulfide (FeS) and magnetite (Fe 3 O 4 ) in the composite was validated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Ciprofloxacin (initial concentration = 20 mg/L) was completely degraded within 45 min in the system catalyzed by this biochar-supported magnetic composite at a dosage of 1.0 g/L. Hydroxyl radicals (·OH) were proved to be the major reactive species contributing to the degradation reaction. The biochar increased the production of ·OH, but decreased the consumption of H 2 O 2 , and helped transform Fe 3+ into Fe 2+ , according to the comparison studies using the unsupported FeS/Fe 3 O 4 as the catalyst. All the three biochars prepared by pyrolysis at different temperatures (400, 500 and 600 • C) were capable for enhancing the reactivity of the iron compound catalyst.

Study on the adsorption of Zn(II) and Cu(II) in acid mine drainage by fly ash loaded nano-FeS

“…1 e and f, the FeS crystals exhibit a flaky morphology and are uniformly dispersed across the surface of the fly ash, with an average length ranging from 40 to 80 nm. This morphology bears a resemblance to the nano FeS synthesized by Wang et al 33 , thereby suggesting, in conjunction with SEM analysis, the efficacy of the ultrasonic precipitation method in loading nano FeS onto fly ash particles. The uniform distribution of nanocrystals on nFeS-F signifies that using fly ash as a carrier can notably enhance the dispersion and stability of nano-FeS, regulate particle size, and effectively mitigate nanoparticle agglomeration.…”

l‐cysteine‐modified Fe3O4 nanoparticles as a novel heterogeneous catalyst for persulfate activation on BTEX removal

“…This indicated that the SFe bond broke during the reaction process and S element existed in a stable form like metal sulfate. The form changing of S element promoted the electron transfer between nFe 3 O 4 core and the solution, iron and iron at the interface, thereby promoting Fe 3+ /Fe 2+ cycle and the catalytic capacity of nFe 3 O 4 (Wang et al, 2019). HO• attacked the benzene ring of BTEX forming various intermediate phenols.…”

Unlocking the potential of catalysts in thermochemical energy conversion processes

“…Some studies demonstrate that iron sulphide (FeS) can be coupled with catalysts to address the unsatisfactory performance of Fe 3 O 4 catalyst which could encourage the production of OH for the breakdown of organic contaminants. 84,85 In a recent work, the honeycombshaped Fe 3 O 4 /FeS composite catalyst made from pollen exhibited phenol degradation efficiency of 95% at 5 minutes and 99% at 60 minutes. 86 The use of catalysts in plastic waste pyrolysis has considerably increased traction.…”