Sonocatalytic degradation of ciprofloxacin using synthesized TiO2 nanoparticles on montmorillonite

TiO2/Montmorillonite (TiO2/MMT) nanocomposite as sonocatalyst was produced by immobilizing synthesized TiO2 on the surface of montmorillonite. The characteristics of produced nanocomposite were investigated using XRD, XRF, FTIR, TEM, SEM, EDX, UV-vis DRS and nitrogen adsorption-desorption analyses. The synthesized TiO2 and TiO2/MMT samples were applied as catalysts for sonocatalytic degradation of ciprofloxacin (CIP). The performance of the TiO2/MMT was greater than pure TiO2 sample in treatment of CIP solution. The degradation efficiency of the CIP by sonocatalytic process was affected by solution pH, catalyst dosage, initial CIP concentrations and ultrasonic power. Degradation efficiency of 65.01% was obtained at the pH of 6, catalyst dosage of 0.2 g L-1, initial CIP concentration of 10 mg L-1 and ultrasonic power of 650 W L-1. It was observed that the presence of inorganic and organic scavengers suppressed the performance of sonocatalytic process. The stability of the nanocomposite was studied in several successive experiments, and the degradation efficiency declined only 61.48% after 4 repeated experiments. The main degradation by-products were recognized by GC-MS method to propose the possible sonocatalytic mechanism for the degradation of CIP. (C) 2016 Elsevier B.V. All rights reserved.