Effective removal of 17-ethynyl estradiol by nano-iron/multi-wall carbon nanotubes composite

In this work, a new composite material was prepared and used to remove 17 alpha-ethinyl estradiol (EE2). The structure and morphology of multi-walled carbon nanotubes (MWNTS), activated multi-walled carbon nanotubes (A-MWNTS) and nano-iron/multi-wall carbon nanotubes (A-MWNTS/Fe) were characterized by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller. The influencing aspects including equilibrium time, A-MWNTS/Fe dosage, pH, initial EE2 concentration, temperature, different materials, and interference factors on the EE2 removal were investigated. The results show that when the time is 20 min, the dosage of A-MWNTS/Fe is 0.015 g, pH is 6-8, the initial concentration of EE2 is 3 mg L-1, and the temperature is within the range of 15 degrees C-25 degrees C, the removal rate of EE2 reach over 99%. Moreover, the adsorption data are in good agreement with the Langmuir isotherm model and the pseudo-second-order kinetic model. EE2 can be removed by A-MWNTS/Fe because of its high practicability and good application prospect, and the removal rate can reach more than 90%. In summary, A-MWNTS/Fe with facile synthesis method, efficient adsorption performance, and excellent reusability shows potential promise for the treatment of wastewater.