Efficient removal of tetracycline by reusable magnetic microspheres with a high surface area

A novel hypercrosslinked magnetic resin Q100 with a high surface area of 1153.8 m(2)/g was prepared and characterized. Another magnetic resin (Q80) and two non-magnetic commercial resins (NDA150 and XAD-4) were selected as adsorbents for comparison to investigate the adsorption behavior and predominant factors controlling the adsorption of tetracycline (TC) onto the adsorbents. The adsorption kinetics of TC onto all resins followed a pseudo-second-order equation. Q100 exhibited much faster kinetics (k(2) = 0.18) than the commercial resins XAD-4 (k(2) = 0.031) and NDA150 (k(2) = 0.021) because of the much smaller particle size of Q100. Moreover, Q100 also had the largest adsorption of the four resins due to its high surface area and abundant mesopore structure. For all of the adsorbents used in the present work, pH 5-6 was suitable for TC adsorption, whereas pH > 12 could be used for regeneration. An increased ionic concentration could enhance the adsorption of TC on the four resins for the salting out effect. The recyclabilities of the four resins were also evaluated, and Q100 was found to be more reusable for TC removal than the other three resins. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.