2023

Wanakai, Indire Sammy; Kareru, Gachoki Patrick; Sujee, Makhanu David; Madivoli, Shigwenya Edwin; Gachui, Maina Ernest; Kairigo, Kinoti Pius

Purpose The presence of antibiotics in water is persistent, bioaccumulative, and harmful to humans and aquatic habitats, so we need to find ways to remove them. This study investigated the kinetics of Rifampicin antibiotic degradation using green synthesized iron oxide nanoparticles. Methods Iron nanoparticles were synthesized using the leaves of Galinsoga parviflora (Gp), Conyza bonariensis (Cb), and Bidens pilosa (Bp). The effect of temperature, pH, time, and adsorbent dose on the rate of degradation of antibiotic by the nanoparticles and their chemical kinetics was evaluated by employing first and second-order kinetics. The efficiency was determined using the percentage degradation of the antibiotic. Results The analysis of degradation was based on the absorbance at the wavelength of absorbance of the Rifampicin antibiotic (475 nm), and the nanoparticles were found to degrade the antibiotic. The antibiotic was degraded by the presence of hydrogen peroxide and the nanoparticles; at a pH of 6.5, 3, and 12, the Conyza bonariensis (CbNPs) nanoparticles were degraded at 78.12, 86.80, and 87.73% within 58, 20, and 30 min, Galinsoga perviflora nanoparticles (GpNPs) at 74.6, 86.8, and 85.9% for 52, 16, and 24 min; and Bidens pilosa nanoparticles (BpNPs) by 79.8, 88.7, and 81.0% for 64, 12, and 24 min, respectively. The dosage of the nanoparticles was found to play a minimal role in degradation, as 20 mg, 10 mg, 5 mg, and 1 mg degraded the antibiotic by 65.5, 48.5, 61.5, and 58.4% for 40, 60, 80, and 144 min. Temperature also effected the degradation of the antibiotic; temperatures of 25, 40, 50, and 60℃ also revealed a reduced time of degradation from 30 to 5 min. Sunlight radiation also had the highest degradation time of 5 min. The degradation of rifampicin using iron oxide nanoparticles was found to be pseudo-second-order, endothermic, and dependent on the reactant dose used during the study, and variation in reaction conditions led to an increase in the percent degradation observed. Conclusion Iron nanoparticles synthesized using Gp, Cb, and Bp could be used as a catalyst in the presence of hydrogen peroxide to degrade rifampicin in aqueous media to carbon IV oxide and water.