Light-assisted catalytic ozonation for efficient degradation of ciprofloxacin using NiO/MoS2 nanocomposite

Abstract

In this study, the hydrothermal method was used to prepare NiO/MoS2 nanocomposite which was employed for the first time in the photocatalytic ozonation (PCO) process to degrade ciprofloxacin antibiotic. The synthesized nanocatalyst was analyzed with various characterization techniques. Response surface methodology (RSM) was utilized to conduct the statistical analysis and optimization of the influential parameters in the degradation process. The maximum efficiency for ciprofloxacin removal (100%) was attained at pH = 5.8, by employing 0.37 g L-1 of the NiO/MoS2 nanocatalyst, an ozone (O3) flow rate of 0.2 g L-1h−1 and duration of 12 min. The results indicated a significant synergistic effect in the analyzed system, which supports the proposal that utilizing the photocatalyst and ozone together through the PCO process is a more efficient method. Also, according to the kinetic analysis data, the PCO process conformed to obey the pseudo-first-order model. Furthermore, the nanocatalyst exhibited a high level of recyclability and stability, retaining 85.44% efficiency after undergoing five successive photocatalytic ozonation cycles. In conclusion, the obtained results confirm that the O3/Vis/NiO/MoS2 system is a promising approach for the treatment of wastewaters containing emerging pharmaceutical contaminants.