Efficient Removal of Tetracycline from Aqueous Media with a Fe3O4 Nanoparticles@graphene Oxide Nanosheets Assembly

• Main Authors: Xinjiang Hu, Yunlin Zhao, Hui Wang, Xiaofei Tan, Yuanxiu Yang, Yunguo Liu
• Format: Article
• Language: English
• Published: MDPI AG 2017-12-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: tetracycline; antibiotic wastewater; Fe3O4@GO; humic acid; ionic strength
• Online Access: https://www.mdpi.com/1660-4601/14/12/1495

A readily separated composite was prepared via direct assembly of Fe3O4 magnetic nanoparticles onto the surface of graphene oxide (GO) (labeled as Fe3O4@GO) and used as an adsorbent for the removal of tetracycline (TC) from wastewater. The effects of external environmental conditions, such as pH, ionic strength, humic acid (HA), TC concentration, and temperature, on the adsorption process were studied. The adsorption data were analyzed by kinetics and isothermal models. The results show that the Fe3O4@GO composite has excellent sorptive properties and can efficiently remove TC. At low pH, the adsorption capacity of Fe3O4@GO toward TC decreases slowly with increasing pH value, while the adsorption capacity decreases rapidly at higher pH values. The ionic strength has insignificant effect on TC adsorption. The presence of HA affects the affinity of Fe3O4@GO to TC. The pseudo-second-order kinetics model and Langmuir model fit the adsorption data well. When the initial concentration of TC is 100 mg/L, a slow adsorption process dominates. Film diffusion is the rate limiting step of the adsorption. Importantly, Fe3O4@GO has good regeneration performance. The above results are of great significance to promote the application of Fe3O4@GO in the treatment of antibiotic wastewater.