Simultaneously implement of both weak magnetic field and aeration for ciprofloxacin removal by Fenton-like reaction

Abstract

This study evaluates the ability of heterogeneous Fenton-like reaction (nano zero-valent iron (NZVI)/H₂O₂) in combination with weak magnetic field (WMF) under continuous oxygen supply by air bubbling for pollutant abatement (using ciprofloxacin as a model pollutant). The considered operating variables were initial pH, catalyst dosage, reaction time and different intensities of magnetic field. Results indicated that NZVI/H₂O₂/aeration/weak magnetic field could effectively decompose ciprofloxacin at neutral condition and higher removal rates are observed at higher pH and NZVI concentrations. Superimposing a weak magnetic field leads to 20% enhancement in ciprofloxacin removal by catalytic Fenton under aeration condition. Employing simultaneously magnetic field induction and aeration exhibit excellent capability to the NZVI oxidation and significantly increased the dissolution rate of iron. Based on Fourier transform infrared spectroscopy, transformation products of NZVI are Fe₃O₄ and FeO(OH). The faster mass transport due to Lorentz and field gradient force, more oxygen diffusion to the iron surface and promoted electrochemical reactions results in more OH° production. Generation of weak magnetic field by permanent magnets and using aeration for both mixing and in situ oxygen supply significantly enhanced the Fenton reaction performance. This combination technology doesn't need any energy input and costly chemicals hence can be used easily for wastewater treatment applications.

Keywords: Aeration; Ciprofloxacin; Fenton; Nano zero-valent iron (NZVI); Weak magnetic field.