title: Chemical adsorption of oxytetracycline from aqueous solution by modified molecular sieves.
abstract: The removal of oxytetracycline (OTC) from aqueous solution on modified molecular sieve via adsorption was investigated in the present work. The copper(II) modified molecular sieve had the much higher adsorbed amount than unmodified one. The bigger pore, the more adsorption sites benefitted for the adsorbed amount of OTC. The exchanged amount of copper(II) and the acid-base property of solution were important factors influencing the removal efficiency. The adsorption kinetics, the adsorption isotherm, the adsorption thermodynamics and the proposed adsorption mechanism were studied. The analysis of adsorption isotherm indicated it is a monolayer adsorption. The fitting with adsorption kinetics, pseudo-second-order model, deduced chemical adsorption is the main rate controlling step. And the new formation of Cu-O chemical bond and the changes at bands of N-H vibration and C-N vibration by Fourier transform infrared spectrometer further confirmed the proposal adsorption mechanism was the chemical complexation of copper(II) in modified 13X with NH2group of OTC. As the real exchanged amount of copper(II) was 149.07 mg·g-1and the solution pH 7.0, the adsorption capacity of modified 13X for OTC reached the maximum of 2,396 mg·g-1(with the initial concentration of 1,000 mg·L-1).
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Junmin
authors.initials: J
authors.lastname: Lv
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Helanshan Rd. 539, Yinchuan 750021, China E-mail: yulongma796@sohu.com.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Chang
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Junzhuo
authors.initials: J
authors.lastname: Fang
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Cai
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory Cultivation Base of Energy Sources and Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
authors.forename: Subing
authors.initials: S
authors.lastname: Fan
mesh_terms: D000143:Acids / Q000737:chemistry; D000327:Adsorption; D003300:Copper / Q000737:chemistry; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008962:Models, Theoretical; D010118:Oxytetracycline / Q000302:isolation & purification*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation*; D014961:X-Ray Diffraction
chemical_list: D000143:Acids; D012996:Solutions; D014874:Water Pollutants, Chemical; D003300:Copper; D010118:Oxytetracycline