Ultrasound assisted green synthesis of silver nanoparticle attached activated carbon for levofloxacin adsorption

The ultrasound assisted green synthesis method was investigated to produce an antibacterial adsorbent for levofloxacin removal from wastewater. The effects of AgNO3/corncob extract ratio, reaction time and US power on synthesis of AgNPs were evaluated. The optimum conditions for the synthesis of silver nanoparticle having the maximum yield were obtained (AgNO3/corncob extract ratio: 1:1 v/v, reaction time: 35 min. US power: 46 W). Silver nanoparticles were synthesized by using corncob extract as reducing agent and deposited to activated carbon under sonication. The specific surface area of silver nanoparticle attached activated carbon increased 33% compared to that of activated carbon due to the pore development effect of ultrasound irradiation. The superior adsorption capacity of silver nanoparticle attached activated carbon can be attributed to its large specific surface area (1842.62 m(2)/g) and average pore diameter (1.18 nm). The adsorption of levofloxacin to activated carbon or silver nanoparticle attached activated carbon showed the best correlation with Langmuir isotherm and pseudo-second order kinetic model. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.