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Open AccessArticle

Simple Urea Immersion Enhanced Removal of Tetracycline from Water by Polystyrene Microspheres

1,†, 2,†, 3, 4, 4 and 1,*
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, China
School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Int. J. Environ. Res. Public Health 2018, 15(7), 1524;
Received: 26 May 2018 / Revised: 8 July 2018 / Accepted: 8 July 2018 / Published: 19 July 2018
(This article belongs to the Special Issue Municipal Wastewater Treatment)
PDF [2666 KB, uploaded 19 July 2018]


Antibiotics pose potential ecological risks in the water environment, necessitating their effective removal by reliable technologies. Adsorption is a conventional process to remove such chemicals from water without byproducts. However, finding cheap adsorbents with satisfactory performance is still a challenge. In this study, polystyrene microspheres (PSM) were enhanced to adsorb tetracycline by surface modification. Simple urea immersion was used to prepare urea-immersed PSM (UPSM), of which surface groups were characterized by instruments to confirm the effect of immersion. Tetracycline hydrochloride (TC) and doxycycline (DC) were used as typical adsorbates. The adsorptive isotherms were interpreted by Langmuir, Freundlich, and Tempkin models. After urea immersion, the maximum adsorption capacity of UPSM at 293 K and pH 6.8 increased about 30% and 60%, achieving 460 mg/g for TC and 430 mg/g for DC. The kinetic data were fitted by first-order and second-order kinetics and Weber–Morris models. The first-order rate constant for TC adsorption on UPSM was 0.41 /h, and for DC was 0.33 /h. The cyclic urea immersion enabled multilayer adsorption, which increased the adsorption capacities of TC on UPSM by two to three times. The adsorption mechanism was possibly determined by the molecular interaction including π–π forces, cation-π bonding, and hydrogen bonding. The simple surface modification was helpful in enhancing the removal of antibiotics from wastewater with similar structures. View Full-Text
Keywords: microsphere resin; urea immersion; adsorption isotherms; surface characterization; kinetics analysis; multilayer adsorption microsphere resin; urea immersion; adsorption isotherms; surface characterization; kinetics analysis; multilayer adsorption

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

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Ma, J.; Li, B.; Zhou, L.; Zhu, Y.; Li, J.; Qiu, Y. Simple Urea Immersion Enhanced Removal of Tetracycline from Water by Polystyrene Microspheres. Int. J. Environ. Res. Public Health 2018, 15, 1524.

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