Adsorption characteristic of ciprofloxacin antibiotic onto synthesized alpha alumina nanoparticles with surface modification by polyanion

In the present study, we reported the first adsorption characteristic of Ciprofloxacin (CFX) antibiotic onto synthesized alumina nanoparticles with surface modification by a polyanion. Strong polyanion poly(styrenesulfonate) (PSS), was used for surface modification of synthesized alumina nanoparticles. The alumina which was structural alpha phase, was confirmed by X-ray diffraction (XRD). The functional vibration groups of AlO and OH was characterized by Fourier transform infrared spectroscopy (FT-IR). The sphere morphology and particle size of about 40 nm was evaluated by Transmission electron microscopy (TEM), while the specific surface area of 6.08 m2/g was determined by Brunauer–Emmett–Teller (BET) method. Surface modification of nanoalumina with PSS enhanced a significant increase in CFX removal from aqueous solution. Some important parameters which influenced to the CFX removal including pH, contact time and adsorbent dosage, were systematically optimized. Under experimentally selected parameters, the removal efficiency and adsorption capacity of CFX using PSS-modified nanoalumina (PMNA) reached maximum of 97.8% and 34.5 mg/g, respectively. Adsorption isotherms of CFX onto PMNA were fitted well by the two-step adsorption model while adsorption kinetics of CFX followed the pseudo-second order. Based on the change in surface charge monitored by zeta potential, surface modification by FT-IR and adsorption isotherms, we suggest that CFX adsorption onto PMNA was induced by both electrostatic and non-electrostatic interactions but electrostatic attraction was dominant. The PMNA were reusable with high removal efficiency for CFX >96%. Removal efficiency for CFX in an actual hospital wastewater sample using PMNA achieved over 75%. Our results indicate that PMNA is a new and excellent adsorbent for antibiotic removal in wastewater treatment. •The α-Al2O3 nanoparticles were successfully synthesized and modified by polyanion PSS to form PMNA.•High removal efficiency of ciprofloxacin (CFX) was 97.8 % and adsorption capacity was 34.5 mg/g.•The PMNA can be reusable with removal efficiency for CFX greater than 96 %.•Removal efficiency of CFX from an actual hospital wastewater sample using PMNA reached to 75%.•Adsorption isotherm and kinetic of CFX were in accordance with two-step and pseudo-second order models, respectively.