Applications of Modified In-Situ Dual Effect of Photocatalysis and PhotoFenton for the Degradation of Ciprofloxacin

Abstract

A novel approach to degrade Ciprofloxacin by using Fe-Ag-TiO2 composite beads was used to carry out modified in-situ dual process (i.e. modified photocatalysis and photo-Fenton). The composite preparation includes the usage of waste materials like clay (acts as binder), foundry sand (FS) and fly ash (FS) for supplementation of iron which induces photo-Fenton. TiO2 was modified using Ag to increase the visible activity of the composite and coated on the surface using dip-coating method. Increase in reaction rate along with reduction of treatment time was observed for the degradation of Ciprofloxacin. 99.4% of degradation was yielded by Fe-Ag-TiO2 composite beads at optimized experimental conditions (H2O2: 300 mgL-1 , area covered by beads: 100%, A/V ratio: 1.134 cm2 mL-1 , Flow rate: 3.5 L/min, pH: 3.5) as the process was carried out under solar irradiations for 60 minutes. Composite was characterized by various techniques like SEM-EDAX, and XRD to assert the Ag, Fe along with distribution of TiO2. Ag reduced the energy band gap of TiO2 from 3.19 eV to 2.72 eV which was calculated from UV-DRS spectra. The systematic leaching of iron took place in this process and was confirmed by iron estimation during the reaction process. Composite beads were stable and active even after the 30 recycles as confirmed by SEM-EDAX. The toxicity of treated antibiotic sample was tested by zone inhibition test which confirmed the elimination of toxicity of treated samples. The mineralization of compound was studied by estimation of various ions like fluoride, nitrate and nitride along with estimation of intermediates formed during the process as identified by GC-MS analysis.