Facile covalent preparation of carbon nanotubes / amine-functionalized Fe3O4 nanocomposites for selective extraction of estradiol in pharmaceutical industry wastewater

Abstract

As a typical steroid hormone drug, estradiol (E2) is also one of the most frequently detected endocrine disrupting chemicals (EDCs) in the aquatic environment. Herein, in response to the potential risk of E2 in steroid hormone pharmaceutical industry wastewater to human and wildlife, a novel carbon nanotubes / amine-functionalized Fe3O4 (CNTs/MNPs@NH2) nanocomposites with magnetic responsive have been developed for the enrichment and extraction of E2 in pharmaceutical industry wastewater, where amino-functionalized Fe3O4 magnetic nanoparticles (MNPs@NH2) were used as a magnetic source. The resultant CNTs/MNPs@NH2 possessed both the features of CNTs and desired magnetic property, enabling to rapidly recognize and separate E2 from pharmaceutical industry wastewater. Meanwhile, the CNTs/MNPs@NH2 had good binding behavior toward E2 with fast binding kinetics and high adsorption capacity, as well as exhibited satisfactory selectivity to steroidal estrogen compounds. Furthermore, the change of pH value of aqueous phase in adsorption solvent hardly affected the adsorption of E2 by CNTs/MNPs@NH2, and the adsorption capacity of E2 ranged from 19.9 to 17.2 mg g−1 in the pH range of 3.0 to 11.0, which is a latent advantage of the follow-up development method to detect E2 in pharmaceutical industry wastewater. As a result, the CNTs/MNPs@NH2 serving as a solid phase extraction medium were successfully applied to efficiently extract E2 from pharmaceutical industry wastewater. Therefore, the CNTs/MNPs@NH2 nanocomposites could be used as a potential adsorbent for removing steroidal estrogens from water. More importantly, the developed method would provide a promising solution for the monitoring and analysis of EDCs in pharmaceutical industry wastewater.