Using recyclable magnetic carbon nanotube to remove micropollutants from aqueous solutions

© 2017 Elsevier B.V. Magnetic carbon nanotubes (MCNs) were synthesized using a new hydrothermal method. The new developed MCNs were evaluated for removal of Metolachlor, Bisphenol-A, Tonalide, Triclosan, Ketoprofen and Estriol from aqueous solutions. Using response surface methodology, a predicting removal model was developed based on solution pH, contact time, adsorbate concentration and adsorbent dose. Experimental results showed high agreement with the predicted ones at optimum conditions. In addition, experimental results were modeled by Freundlich and Langmuir isotherms, which directed a better fit to the Langmuir isotherm. MCN presented good adsorption capacity in which Bisphenol-A, Ketoprofen and Tonalide were the most effectively removed micropollutants, with 98, 96 and 96% removal within 47 min, respectively. Thermodynamic studies showed that the adsorption process was endothermic and spontaneous for the micropollutants. Adsorbate regeneration studies were done with methanol, ethanol, HCl, NaOH and hydrogen peroxide in five regenerating cycles. Methanol had the highest level of adsorbent recovery. MCN can be used as a sustainable adsorbent for adsorption of the studied micropollutants