Stimulation of peroxymonosulfate using nickel ferrite nanoparticles for the degradation of Lomefloxacin hydrochloride and caffeine

Abstract

Lomefloxacin Hydrochloride (LFH), an antibacterial agent, and caffeine (CAF), a cognitive enhancer, are excreted by humans and end up in municipal sewage effluents and surface waters. This pharmaceutical concentration in bodies of water/treatment plants poses a serious threat to both aquatic habitats and humans. A laboratory batch study on the degradation of LFH, CAF and LC (CAF and LFH mixed solution) was carried out using NFO nanoparticles to stimulate potassium peroxymonosulfate (PMS). The NFO nanoparticles were synthesized through a co-precipitation method and characterised using FTIR, XRD, FESEM/EDX, TGA/DTA/DTG, BET, AFM, VSM, and Zeta potential. The particle size distribution from FESEM (using ImageJ software) revealed that 83.3% of particles are ≤ 100 nm, its mean and standard deviation were estimated to be 43.87 nm and 20 to 25 nm. The NFO nanoparticles’ specific surface area was estimated to be 112.02 m²/g, and the magnetic properties of the NFO nanoparticles were investigated using VSM analysis. The parametric study included bare NFO, PMS without catalyst, pH, catalyst dosage, PMS variation with optimized catalyst, initial concentration of LFH and CAF, and reaction time, with nearly 94.34% LFH was degraded in 220 min, 100% CAF was degraded in 80 min, 78.07% LC was degraded in 40 min. The degraded compounds m/z of LFH, CAF and LC were identified using LC–MS. The recycling and regeneration of NFO nanoparticles were investigated to determine the stability of the NFO nanoparticles in the degradation of LFH and CAF in which the degradation efficiency decreased to 90.68% and 64.1% respectively upon the third wash with distilled water. As a result, the NiFe<inf>2</inf>O<inf>4</inf>/PMS system showed improved degradation even after three recycle runs, making it an efficient and economical system for degrading LFH, CAF and even to multi-pharmaceutical pollutants.