Adsorption and catalytic oxidation of pharmaceuticals by nitrogen-doped reduced graphene oxide/Fe3O4 nanocomposite

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 341; pp. 361 - 370
• Main Authors: Peng, Guilong, Zhang, Menghan, Deng, Shubo, Shan, Danan, He, Qiang, Yu, Gang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2018
• Subjects: Adsorption; Degradation; Ketoprofen; Norfloxacin; Persulfate; Degradation; Adsorption; Norfloxacin; Ketoprofen; Persulfate
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.02.064

[Display omitted] •N-RGO/Fe3O4 is prepared by N modified reduced graphene oxide with Fe3O4.•N-RGO/Fe3O4 nanocomposite has high adsorption capacity for pharmaceuticals.•Maximum adsorption capacity of N-RGO/Fe3O4 for norfloxacin is 158.1 mg/g.•N-RGO/Fe3O4 exhibits the catalytic oxidation of the adsorbed pharmaceuticals.•N-RGO/Fe3O4 can activate persulfate to generate both OH and SO4−. A novel nanocomposites (N-RGO/Fe3O4) with the function of adsorption and catalytic degradation of pharmaceuticals in water was successfully synthesized through a facile hydrolysis process. The nitrogen modified reduced graphene oxide (N-RGO) incorporated with magnetic Fe3O4 nanoparticles could enhance its adsorption and catalytic activity, and allowed the magnetic separability. The as-prepared N-RGO/Fe3O4 exhibited relatively fast adsorption for norfloxacin (NOR) and ketoprofen (KP), and the maximum adsorption capacity on the N-RGO/Fe3O4 was 158.1 mg/g for NOR and 468.0 mg/g for KP according to the Langmuir fitting. The N-RGO/Fe3O4 composite could activate persulfate (PS) to generate active radicals. NOR degradation kinetics and pathway by N-RGO/Fe3O4/PS system were also investigated. A complete removal of NOR (20 mg/L) was achieved within 210 min with the addition of 10 mmol/L S2O82− and 100 mg/L N-RGO/Fe3O4, and the removal efficiency of total organic carbon (TOC) was 89%. Electron spin resonance (ESR) tests verified that both OH and SO4− were produced in the catalytic oxidation process, and OH played a significant role in the N-RGO/Fe3O4/PS system.